tag:theconversation.com,2011:/au/topics/botany-386/articlesBotany – The Conversation2023-11-09T13:32:30Ztag:theconversation.com,2011:article/2163262023-11-09T13:32:30Z2023-11-09T13:32:30ZCranberries can bounce, float and pollinate themselves: The saucy science of a Thanksgiving classic<figure><img src="https://images.theconversation.com/files/558166/original/file-20231107-21-cmo43c.jpg?ixlib=rb-1.1.0&rect=15%2C9%2C2029%2C1140&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cranberries grow on vines in sandy bogs and marshes.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/Mm6QhN">Lance Cheung, USDA/Flickr</a></span></figcaption></figure><p>Cranberries are a staple in U.S. households at Thanksgiving – but how did this bog dweller end up on holiday tables? </p>
<p>Compared to many valuable plant species that were domesticated over thousands of years, cultivated cranberry (<em>Vaccinium macrocarpon</em>) is a young agricultural crop, just as the U.S. is a young country and Thanksgiving is <a href="https://theconversation.com/how-advertising-shaped-thanksgiving-as-we-know-it-86819">a relatively new holiday</a>. But <a href="https://soilcrop.tamu.edu/people/desalvio-serina/">as a plant scientist</a>, I’ve learned much about cranberries’ ancestry from their botany and genomics.</p>
<h2>New on the plant breeding scene</h2>
<p>Humans have cultivated <a href="https://doi.org/10.1007/s10437-018-9314-2">sorghum for some 5,500 years</a>, <a href="https://www.nsf.gov/news/news_summ.jsp?cntn_id=114445">corn for around 8,700 years</a> and <a href="https://doi.org/10.1534/g3.120.401362">cotton for about 5,000 years</a>. In contrast, cranberries were domesticated around 200 years ago – but people were eating the berries before that.</p>
<p>Wild cranberries are native to North America. They were an important food source for Native Americans, who used them in puddings, sauces, breads and a <a href="https://www.cranberries.org/exploringcranberries/into/maki_back.html">high-protein portable food called pemmican</a> – a carnivore’s version of an energy bar, made from a mixture of dried meat and rendered animal fat and sometimes studded with dried fruits. Some tribes <a href="https://lakotarednations.com/2017/11/wo-lakota-making-wasna/">still make pemmican today</a>, and even <a href="https://tankabar.com/">market a commercial version</a>. </p>
<p>Cranberry cultivation began in 1816 in Massachusetts, where Revolutionary War veteran Henry Hall found that <a href="https://www.youtube.com/watch?v=nt7NA7G808Y&t=5s">covering cranberry bogs with sand</a> fertilized the vines and retained water around their roots. From there, the fruit spread throughout the U.S. Northeast and Upper Midwest. </p>
<p>Today, <a href="https://www.ers.usda.gov/data-products/chart-gallery/gallery/chart-detail/?chartId=102649">Wisconsin produces roughly 60%</a> of the U.S. cranberry harvest, followed by Massachusetts, Oregon and New Jersey. Cranberries also are grown in Canada, where they are <a href="https://canadianfoodfocus.org/in-season/whats-in-season-cranberries/">a major fruit crop</a>.</p>
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<a href="https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Four men in waders, holding long rakes, thigh-deep in a flooded bog, its surface covered with floating cranberries." src="https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=305&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=305&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=305&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=383&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=383&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558168/original/file-20231107-29-f3xdq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=383&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Farmers often flood cranberry bogs to harvest the fruit, which they rake loose from the vines.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/bBmqts">Michael Galvin, Massachusetts Office of Travel and Tourism/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>A flexible and adaptable plant</h2>
<p>Cranberries have many interesting botanical features. Like roses, lilies and daffodils, cranberry flowers are hermaphroditic, which means they <a href="https://www.gardeningknowhow.com/garden-how-to/info/hermaphroditic-plant-information.htm">contain both male and female parts</a>. This allows them to self-pollinate instead of relying on birds, insects or other pollinators. </p>
<p>A cranberry blossom has four petals that peel back when the flower blooms. This exposes the anthers, which contain the plant’s pollen. The flower’s resemblance to the beak of a bird earned the cranberry its original name, <a href="https://gobotany.nativeplanttrust.org/species/vaccinium/macrocarpon/">the “craneberry</a>.” </p>
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<a href="https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A flower with four curved white petals tinged with pink." src="https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=742&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=742&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=742&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=932&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=932&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558169/original/file-20231107-23-zvban6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=932&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A blossom on a cranberry bush in Wisconsin.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Cranberry_Blossom_%289180939392%29.jpg">Aaron Carlson/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>When cranberries don’t self-pollinate, they rely on bumblebees and honeybees to transport their pollen from flower to flower. They can also be propagated sexually, by planting seeds, or asexually, through rooting vine cuttings. This is important for growers because seed-based propagation allows for higher genetic diversity, which can translate to things like increased disease resistance or more pest tolerance. </p>
<p>Asexual reproduction is equally important, however. This method allows growers to create clones of varieties that perform very well in their bogs and grow even more of those high-performing types.</p>
<p>Every cranberry <a href="https://www.wisfarmer.com/story/news/2018/07/13/farm-technology-days-five-fun-cranberry-facts/784392002/">contains four air pockets</a>, which is why they float when farmers flood bogs to harvest them. The air pockets also make raw cranberries bounce when they are dropped on a hard surface – a good indicator of whether they are fresh.</p>
<p>These pockets serve a biological role: They enable the berries to float down rivers and streams to disperse their seeds. Many other plants disperse their seeds via animals and birds that eat their fruits and excrete the seeds as they move around. But as anyone who has tasted them raw knows, cranberries are ultra-tart, so they have <a href="https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_viopa2.pdf">limited appeal for wildlife</a>. </p>
<h2>Reading cranberry DNA</h2>
<p>For cranberries being such a young crop, scientists already know <a href="https://doi.org/10.1002/9781119616801.ch8">a lot about their genetics</a>. The cranberry <a href="https://www.genome.gov/genetics-glossary/Diploid">is a diploid</a>, which means that each cell contains one set of chromosomes from the maternal parent and one set from the paternal parent. It has 24 chromosomes, and its genome size is less than one-tenth that of the human genome. </p>
<p>Insights like these help scientists better understand where potentially valuable genes might be located in the cranberry genome. And diploid crops tend to have fewer genes associated with a single trait, which makes breeding them to emphasize that trait much simpler. </p>
<p>Researchers have also described the genetics of the cultivated cranberry’s wild relative, which is known as the “<a href="https://plants.usda.gov/DocumentLibrary/plantguide/pdf/cs_vaox.pdf">small cranberry” (<em>Vaccinium oxycoccos</em>)</a>. Comparing the two can help scientists determine where the cultivated cranberry’s agronomically valuable traits reside in its genome, and where some of the small cranberry’s cold hardiness might come from. </p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CxGCZq0xv16/?utm_source=ig_web_copy_link","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>Researchers are <a href="https://www.vacciniumcap.org/">developing molecular markers</a> – tools to determine where certain genes or sequences of interest reside within a genome – to help determine the best combinations of genes from different varieties of cranberry that can enhance desired traits. For example, a breeder might want to make the fruits larger, more firm or redder in color.</p>
<p>While cranberries have only been grown by humans for a short period of time, they have been evolving for much longer. They entered agriculture with a long genetic history, including things like <a href="https://doi.org/10.1371/journal.pone.0264966">whole genome duplication events and genetic bottlenecks</a>, which collectively change which genes are gained or lost over time in a population. </p>
<p>Whole genome duplication events occur when two species’ genomes collide to form a new, larger genome, encompassing all the traits of the two parental species. Genetic bottlenecks occur when a population is greatly reduced in size, which limits the amount of genetic diversity in that species. These events are extremely common in the plant world and can lead to both gains and losses of different genes. </p>
<p>Analyzing the cranberry’s genome can indicate when it diverged evolutionarily from some of its relatives, such as the blueberry, lingonberry and huckleberry. Understanding <a href="https://theconversation.com/modern-tomatoes-are-very-different-from-their-wild-ancestors-and-we-found-missing-links-in-their-evolution-130041">how modern species evolved</a> can teach plant scientists about how different traits are inherited, and how to effectively breed for them in the future.</p>
<h2>Ripe at the right time</h2>
<p>Cranberries’ close association with Thanksgiving was simply a practical matter at first. Fresh cranberries are ready to harvest from mid-September through mid-November, so Thanksgiving falls within that perfect window for eating them. </p>
<p>Cranberry sauce was first loosely described in accounts from the American colonies in the 1600s, and appeared in a <a href="https://www.smithsonianmag.com/history/what-americas-first-cookbook-says-about-our-country-its-cuisine-180967809/">cookbook for the first time in 1796</a>. The berries’ tart flavor, which comes from <a href="https://rucore.libraries.rutgers.edu/rutgers-lib/60677/">high levels of several types of acids</a>, makes them more than twice as acidic as most other edible fruits, so they add a welcome zing to a meal full of blander foods like turkey and potatoes.</p>
<p>In recent decades, the cranberry industry has branched out into <a href="https://theconversation.com/can-cranberries-conquer-the-world-a-us-industry-depends-on-it-87912">juices, snacks and other products</a> in pursuit of year-round markets. But for many people, Thanksgiving is still the time when they’re most likely to see cranberries in some form on the menu.</p><img src="https://counter.theconversation.com/content/216326/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Serina DeSalvio does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Cranberries add color and acidity to Thanksgiving menus, but they also have many interesting botanical and genetic features.Serina DeSalvio, Ph.D. Candidate in Genetics and Genomics, Texas A&M UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2106162023-09-20T12:25:33Z2023-09-20T12:25:33ZTake a break from your screen and look at plants − botanizing is a great way to engage with life around you<figure><img src="https://images.theconversation.com/files/548424/original/file-20230914-27-ilf6bk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You may be surprised by what's growing on a familiar trail.</span> <span class="attribution"><span class="source">Benjamin Goulet-Scott</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>When you hear about the abundance of life on Earth, what do you picture? For many people, it’s animals – but awareness of plant diversity is growing rapidly.</p>
<p>Our planet has <a href="https://www.mobot.org/mobot/research/apweb/">nearly 300,000 species of flowering plants</a>. Among animals, only beetles can compete with that number. There are more species of ferns than birds, more mints than mammals, and more beans than butterflies. Measured in total mass, plants make up <a href="https://doi.org/10.1073/pnas.1711842115">82% of all life on land across the globe</a>.</p>
<p>We are plant scientists and co-founders of <a href="https://www.letsbotanize.org/">Let’s Botanize</a>, an educational nonprofit that uses plant life to teach about ecology, evolution and biodiversity. In the past several years we have witnessed a <a href="https://doi.org/10.1002/ppp3.10257">botanical boom</a>, with <a href="https://theconversation.com/the-pandemics-gardening-boom-shows-how-gardens-can-cultivate-public-health-181426">participation in plant-based hobbies surging</a>. From cultivating houseplants to foraging for wild foods and <a href="https://www.fox10phoenix.com/news/over-2-in-5-us-households-now-growing-food-following-pandemic-boom">outdoor gardening</a>, plant appreciation is on the rise.</p>
<p><a href="https://www.merriam-webster.com/dictionary/botanize">Botanizing</a> is spending time alongside plants in order to observe and appreciate them as living organisms – like birding, but with subjects that stay in place. When you botanize, a simple walk in the woods becomes an immersive experience shared with many species. Getting to know your nonhuman neighbors is a way to engage with a changing planet.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/reel/Cw2xvLgO-u9/?hl=en","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Plant collecting and colonialism</h2>
<p>Botanizing has a deep and checkered history. Humans have been analyzing and classifying plants for <a href="https://huh.harvard.edu/book/chapter-2-brief-history">thousands of years</a>, often to figure out what they can safely eat or cultivate. </p>
<p>When Europeans began exploring and colonizing other parts of the world, they were interested in finding plants that were useful as food, medicine or for other purposes. For example, in the early 17th century, the Dutch East India Company <a href="https://historibersama.com/the-voc-genocide-historia/">forcibly colonized the Banda Islands</a> in what is now Indonesia in order to monopolize the cultivation and lucrative trade of nutmeg (<em>Myristica fragrans</em>).</p>
<p>In 19th-century England, Victorians became obsessed with plants, especially ferns. This craze came to be known as <a href="https://www.historic-uk.com/CultureUK/Pteridomania-Fern-Madness/">pteridomania, or fern fever</a>. It coincided with the height of European imperialism across the globe, which included widespread collection of valuable plants from faraway places. </p>
<p>Today, however, many botanic gardens and <a href="http://arbnet.org/whats-arboretum">arboreta</a> – gardens that focus on trees and shrubs – have shifted their mission to public education, scientific research and biodiversity conservation. They can be good resources for learning to botanize.</p>
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<figcaption><span class="caption">An estimated 40% of the world’s plant species are at risk of extinction, including many that haven’t yet been identified.</span></figcaption>
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<h2>Why botanize?</h2>
<p>Plants provide raw materials for the homes we live in, the food we eat and the oxygen we breathe. Without them, life as humans know it could not exist. </p>
<p>Nonetheless, many people think of plants more as a backdrop to life, rather than as a central part of it. Scientists and educators call this phenomenon <a href="https://doi.org/10.1002/ppp3.10153">plant awareness disparity</a> – a widespread cognitive bias that leads people to underestimate the diversity and importance of plants. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Light glistening off orange staghorn sumac leaves covered in morning dew." src="https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545167/original/file-20230829-26-f0vm7l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Staghorn sumac (<em>rhus typhina</em>) absorbing the last bits of nutrients from its dying leaves on a brisk fall morning as it prepares for winter dormancy.</span>
<span class="attribution"><span class="source">Let's Botanize, Inc.</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
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<p>Research has shown the value of being outside in <a href="https://doi.org/10.1080/09638237.2020.1755027">natural green areas</a> or <a href="https://doi.org/10.1016/j.envres.2020.110420">around plants indoors</a>. Even traditional western doctors are starting to <a href="https://time.com/6171174/nature-stress-benefits-doctors/">prescribe nature walks</a> to reduce stress and improve physical well-being. Botanizing can provide a reason to get outdoors, and spending time closely observing plants’ minute structures is a great <a href="https://theconversation.com/mindfulness-meditation-and-self-compassion-a-clinical-psychologist-explains-how-these-science-backed-practices-can-improve-mental-health-198731">mindfulness practice</a>. </p>
<p>We also see botanizing as a valuable alternative to spending time on social media. As many experts have observed, online platforms have become so individually tailored by algorithms that each user participates in their own version of reality, a trend that has enabled increasingly <a href="https://doi.org/10.1007/s42001-020-00084-7">combative and antisocial behavior</a>. Botanizing is an opportunity to take a break from these tailored worlds and deeply engage with local human and nonhuman communities.</p>
<p>Finally, since plants form the foundation of life on Earth, caring for plants is a way of caring for our planet. Botanizing is one simple way to inspire change in other aspects of our lives that prioritizes sustainability. </p>
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<a href="https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Unfurling fiddlehead of the interrupted fern" src="https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545170/original/file-20230829-18-f0vm7l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ferns don’t produce flowers or fruits. Instead they reproduce by freely dispersing spores. Spores are produced in small structures called sporangia, which line the edges of the leaflets in this interrupted fern (<em>claytosmunda claytoniana</em>).</span>
<span class="attribution"><span class="source">Let's Botanize, Inc.</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Tools of the trade</h2>
<p>There are many ways to botanize. Typically it involves trying to identify a plant species, observing its form and structure or assessing how it survives in the landscape. Plants are everywhere and don’t move, so this can be done in virtually any setting, including your windowsill or sidewalk.</p>
<p>So, how do you start? You can focus on plant structure, ecology, interactions, colors, textures or scents – or tastes, if you’re bold. You don’t need to travel far or spend a lot of money. There’s much to learn from your houseplants, <a href="https://theconversation.com/how-do-spices-get-their-flavor-202591">the food you cook</a>, the wood grain of your furniture, the plants growing in your sidewalks, gardens or local green spaces. </p>
<p>Here are a few essential tools: </p>
<p>– A <a href="https://www.nhbs.com/blog/the-nhbs-guide-to-hand-lenses">hand lens</a> is a window into the minutia of the botanical world. It’s as essential for a botanist as binoculars are for a birder. We recommend one with 10x magnification – that is, one that magnifies what you’re looking at by a factor of 10.</p>
<p>– A local field guide is your reference textbook. A good field guide to your local plants will have images and detailed text that you can use to cross-reference your identifications. </p>
<p>– A plant identification app can help confirm your identifications. Machine learning algorithms are getting increasingly good at matching plant images with species. One popular choice is <a href="https://play.google.com/store/apps/details?id=org.inaturalist.seek&hl=en&gl=US">the Seek app</a>, which is <a href="https://www.inaturalist.org/pages/what+is+it">powered by iNaturalist</a>, an online social network where people share information about living species and get help with identifications.</p>
<p>– Almost every region of the U.S. has local botanical clubs that typically hold regular meetings and organize workshops, online groups, botanizing days and more. Joining one is a great way to meet and learn from people with similar interests. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Light passing through a white flower with red stamens." src="https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545176/original/file-20230829-21-lde0bw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Flowers like this magnolia (<em>magnolia sieboldii</em>) have evolved to entice insects and other pollinators visually. The magnolia’s blood-red stamens produce pollen, and its cream-colored column of fused carpels produces seeds.</span>
<span class="attribution"><span class="source">Let's Botanize, Inc.</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To germinate your initial interest, we recommend searching for a spark plant – one that excites, engages or is meaningful to you. It can be a plant that you are familiar with but haven’t seen growing in real life, one that is totally new to you, or one that you associate with a special moment. </p>
<p>If botanizing is to reclaim its place as a nature-based hobby, we believe it is important to reimagine it as a critically evolved 21st century pastime. That means looking at plants with appreciation – not simply as products for human use but as foundational and interconnected members of life on Earth.</p><img src="https://counter.theconversation.com/content/210616/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacob S. Suissa is co-founder of the educational not-for-profit Let's Botanize, Inc.</span></em></p><p class="fine-print"><em><span>Ben Goulet-Scott is co-founder of the educational not-for-profit Let's Botanize, Inc. </span></em></p>Botanizing is the practice of observing and appreciating plant life. Two plant scientists explain how it benefits people and the planet.Jacob S. Suissa, Assistant Professor of Plant Evolutionary Biology, University of TennesseeBen Goulet-Scott, Higher Education & Laboratory Coordinator at Harvard Forest, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2045302023-07-12T20:03:56Z2023-07-12T20:03:56ZFrench botanist Théodore Leschenault travelled to Australia in 1800-1803. His recently recovered journal contains a wealth of intriguing information<figure><img src="https://images.theconversation.com/files/526088/original/file-20230515-27-ummfq5.jpg?ixlib=rb-1.1.0&rect=141%2C28%2C3626%2C2274&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Charles-Alexandre Lesueur, Leschenault aboard the Géographe. Pencil on paper. Muséum d'histoire naturelle, Le Havre, inv. 13033.</span> </figcaption></figure><p><em>Content warning: this article describes outdated and potentially offensive terminology when referring to First Nations people.</em></p>
<p>In the storeroom of a square-towered château in Burgundy, my genial hosts gestured towards a large, wooden chest of drawers. I pulled open a compartment and began sorting through bundles of old papers – house records from the 18th and 19th centuries. I was there, in 2015, on the trail of Théodore Leschenault, a botanist who had travelled to Australia in the years 1800 to 1803 with the expedition of discovery led by Nicolas Baudin. </p>
<p>The château belonged to Leschenault’s descendants, who had invited me to explore the family archives. There was a register detailing his divorce from his young wife Marguerite due to their “incompatible temperaments”. There were shells and rocks bearing faded ink labels. And there was a printed invitation to a funeral service held for him at the Madeleine church in Paris in 1826 after he died of a stroke. </p>
<p>All this was valuable research material but I felt a slight sense of disappointment. The original manuscript journal of his voyage to Australia was not there.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-the-voyage-of-nicolas-baudin-and-art-in-the-service-of-science-62038">Friday essay: the voyage of Nicolas Baudin and 'art in the service of science'</a>
</strong>
</em>
</p>
<hr>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=766&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=766&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=766&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=962&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=962&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526109/original/file-20230515-2440-9gqh6y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=962&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Langlumé, portrait of Théodore Leschenault.</span>
<span class="attribution"><span class="source">Private Collection</span></span>
</figcaption>
</figure>
<p>Prior to this I had been working on a translation of the only version of the journal thought to exist, an incomplete copy made for the navy by an unknown hand. But then, in late 2016, out of the blue, the original journal in Leschenault’s own handwriting was put up for auction in Royan on the west coast of France. Where the journal had been for the previous 200 years was not revealed.</p>
<p>After bidding closed at €110,000 ($A180,500), the French government stepped in, seizing the journal as its own property, on the grounds that it had funded the original expedition. The journal was deposited with the National Archives of France, which in 2020 provided me with scans to use as the basis for <a href="https://uwap.uwa.edu.au/products/the-french-collector-journal-and-letters-of-theodore-leschenault">a new translation</a> that appears in my book The French Collector.</p>
<p>This journal contains a store of fascinating new information. Two previously unknown chapters describe the first part of Leschenault’s journey from Paris to Le Havre and onward via the Canary Islands and Mauritius to the west Australian coast. They offer much else besides, including insights into his fears and ambitions, an array of scientific observations, and impassioned discussions of slavery and the treatment of Indigenous peoples.</p>
<h2>A collecting frenzy</h2>
<p>Leschenault was 26 when he set out from France with the Baudin expedition to explore the “unknown coasts” of New Holland. Sociable by nature, with a head of blond curls, he came from a wealthy legal family and had been imprisoned during the French Revolution. A child of the Enlightenment, with an anti-religious and empirical cast of mind, he hoped to forge a career as a botanist.</p>
<p>When Leschenault went ashore for the first time on the Australian coastline in June 1801, at <a href="https://en.wikipedia.org/wiki/Geographe_Bay">Geographe Bay</a> in the south-west, he immediately went into a collecting frenzy, picking up so many shells, pebbles and plants he couldn’t carry them all back to the boat. </p>
<p>Here he saw grass trees and <a href="https://www.bushlandperth.org.au/campaigns/celebrating-tuart-woodlands/">tuart trees</a>, black swans and a dingo, and had a much anticipated first encounter with some Wardandi Noongar men. Over the next two years, Leschenault collected thousands of plant and animal specimens as the expedition explored three sides of the continent.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=371&fit=crop&dpr=1 600w, https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=371&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=371&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/535240/original/file-20230703-27-5yd59p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In June 1801, Leschenault saw grass trees for the first time.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-a-rare-bird-how-europeans-got-the-black-swan-so-wrong-161654">Friday essay: a rare bird — how Europeans got the black swan so wrong</a>
</strong>
</em>
</p>
<hr>
<p>All the officers and scientists on the voyage were required to keep a record of their experiences. Some are terse maritime affairs – lists of bearings, wind directions and similar data. Leschenault’s is among the most eloquent and wide-ranging. These writings all supplement the official record of the expedition, the <em>Voyage de découvertes aux terres australes</em>, published by François Péron and Louis Freycinet between 1807 and 1816.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526110/original/file-20230515-27-p8ikxd.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Journal of Théodore Leschenault, 1800-1802.</span>
<span class="attribution"><span class="source">Archives Nationales (France): MAR/5JJ/56/B.</span></span>
</figcaption>
</figure>
<p>Leschenault’s original journal is a battered-looking object, a large notebook with torn cloth covers, muddy-brown in colour, with the words “private journal” written on the front. Inside, the paper is well preserved and his handwriting spills in neat, brown ink along hand-ruled lines.</p>
<p>The two previously unknown chapters contain an invaluable ragbag of materials about the voyage. Into these chapters he copied a whole sheaf of loose-leaf jottings he had done earlier: private letters, interviews with travellers, short essays on different phenomena (atmospheric humidity, sea temperatures and phosphorescence), philosophical reflections, descriptions of plants and animals, alongside a more conventional daily narrative.</p>
<p>The emotional register of these early chapters shifts according to his imagined audience. When he sees the sea for the first time at Le Havre, for example, he describes for friends and family his terror at the thought that he might drown beneath the waves. But his language becomes more austere when detailing natural phenomena for scientific readers.</p>
<h2>Colonisation and slavery</h2>
<p>Some of the most unexpected passages in the new chapters relate to slavery and the effects of colonisation. In Australia, he quickly came to the conclusion that the local peoples, “far from a state of civilisation” and prone to treachery, disproved the idea of the “noble savage”. But the early chapters reveal that he arrived with sympathetic preconceptions.</p>
<p>While on Tenerife, one of the Canary Islands, he learnt about the fate of the island’s original Guanche inhabitants – which gave him reason for concern. Spanish invaders had come with firearms and confronted a peaceful community of farmers. “Oppression and despair drove this people to extinction,” he writes. “Now we are setting out to visit unknown peoples; perhaps the moment of their discovery will be the start of their misfortune”. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-the-myth-of-the-noble-savage-55316">Explainer: the myth of the Noble Savage</a>
</strong>
</em>
</p>
<hr>
<p>Leschenault contemplates the bleakest of fates for Indigenous Australians, before changing his mind: “But no, that can’t be true, today governments are more enlightened, they will be just […]”</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526111/original/file-20230515-19-i2fvqh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Inside the journal.</span>
<span class="attribution"><span class="source">Archives Nationales (France): MAR/5JJ/56/B.</span></span>
</figcaption>
</figure>
<p>Leschenault also takes an interest in a marginal figure among the scientific staff, the teenage assistant gardener and former slave who was referred to by the derisive nickname Merlot (“little blackbird”). He sympathetically recovers the youth’s original name, Bognam-Nonen-Derega (meaning “everlasting happiness”), copies down details about life in his home village (in what is perhaps now eastern Nigeria) and records the story of how he was kidnapped at the age of 12 and sold to English slavers. Later, on Mauritius, Leschenault directly addresses moral questions around slavery. </p>
<p>It is, he declares, “an outrage against nature” but he understands why, for economic reasons, it cannot be abolished immediately. His sympathies are prone to fluctuation though: when he interviews an albino Mauritian slave girl, his manner seems much less compassionate.</p>
<p>The recently recovered journal traces Leschenault’s travels over the course of two years but comes to an abrupt end in Sydney, at the half-way point of the expedition. What happened afterwards – did he start to write a second volume, now lost? </p>
<p>When he abandoned the expedition due to illness at Timor in June 1803, he gave all his papers to Baudin: drawings, botanical notebooks, possibly even a sequel to the journal. But the whole bundle of papers disappeared without a trace. Perhaps they linger in some storeroom, awaiting their moment to re-emerge into the light …</p><img src="https://counter.theconversation.com/content/204530/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Gibbard has received funding for his research from the Australian Research Council.</span></em></p>Two previously unknown chapters of a 19th century French botanist’s journal offer insights into his fears and ambitions, scientific observations, and discussions of the effects of colonisation.Paul Gibbard, Senior Lecturer in French Studies, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2066162023-06-16T02:47:04Z2023-06-16T02:47:04ZWhy does grass grow more slowly in winter?<figure><img src="https://images.theconversation.com/files/529716/original/file-20230602-27-104el8.jpg?ixlib=rb-1.1.0&rect=0%2C21%2C4859%2C3195&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A reader of The Conversation recently wrote in to ask:</p>
<blockquote>
<p>Why does grass grow slower in winter?</p>
</blockquote>
<p>It is a great question and at first the answer might seem obvious. There is less sunlight and it is colder in the winter months. This affects grass and plant growth in general. </p>
<p>However, there is more to it than meets the eye. Different grasses respond to and cope with winter in different ways.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529715/original/file-20230602-29-weta8e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=589&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It can be hard to keep up with lawn growth in summer. Winter, however, is a different story.</span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ive-created-a-monstera-how-to-care-for-the-swiss-cheese-plant-in-your-life-202851">I’ve created a monstera! How to care for the ‘Swiss cheese plant’ in your life</a>
</strong>
</em>
</p>
<hr>
<h2>Grass: a recent arrival</h2>
<p>Grasses are relatively recent arrivals in plant evolution, first appearing in fossil records about <a href="https://academic.oup.com/plphys/article/125/3/1198/6109905">65 million years ago</a> and becoming widespread in parts of Asia by about <a href="https://academic.oup.com/plphys/article/125/3/1198/6109905">30 million years ago</a>.</p>
<p>Geologically, and in plant evolutionary time scales, this is quite recent. It means much of grass evolution has occurred under modern geological, environmental and climatic conditions. So, more than most plants, grasses have adapted to a modern, if pre-human, world. This affects their climatic responses.</p>
<p>Some of our best-known grasses evolved from ancestors that first appeared on Earth hundreds of millions of years ago.</p>
<p>Their physiology developed to cope with an Earth that had a very different atmosphere from that of today.</p>
<p>These plants have a type of photosynthesis called <a href="https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/native-pastures/what-are-c3-and-c4-native-grass">C3 metabolism</a>.</p>
<h2>What is C3 metabolism?</h2>
<p>C3 metabolism is about how the plant does the job of turning light, water and air into food (photosynthesis).</p>
<p>About <a href="https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095545945;jsessionid=F1D6CE7E04A3DF20C48A6949F4A2F683#:%7E:text=C3%20plants%20make%20up%20over,let%20in%20more%20carbon%20dioxide">95%</a> of all plants you can think of – trees, shrubs, annuals, fruits, vegetables and many traditional (often called cool season) grasses – have C3 metabolism.</p>
<p>Plants with this form of photosynthesis tend to grow well in a wide range of environmental conditions, even if the temperature is cooler and there are higher than usual levels of carbon dioxide in the air.</p>
<p>They tend to remain green all year round if water is available, and may continue to grow well through late autumn. Many are frost-tolerant, but they may become dormant in hot dry weather. </p>
<p>C3 grasses, such as ryegrass, do slow their growth for the winter months as sunlight becomes less intense. Their metabolic processes (in this case, photosynthesis) slow down when the temperature <a href="https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/native-pastures/what-are-c3-and-c4-native-grass">drops</a>. </p>
<p>Biological reactions are chemical reactions, after all. The rate of a reaction is temperature-dependent – speeding up when it’s warmer and slowing down or even stopping when it gets colder. </p>
<p>But they tend to do better in winter than their cousins, the C4 grasses. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529717/original/file-20230602-21-o6v4bp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some grasses struggle in the cold more than others.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>I’ve heard many lawn grasses are C4 grasses. What does that mean?</h2>
<p>As the level of CO₂ in the atmosphere declined and geological events led to the development of tropical regions around the equator, a different group of plants evolved. These plants used a form of photosynthesis called C4 metabolism.</p>
<p><a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.13033">C4</a> plants grow very well under lower CO₂ levels in the atmosphere, use water more efficiently, and can cope with poor soils better than C3 grasses. </p>
<p>But they struggle in the cold. They grow best in warmer, wetter conditions.</p>
<p>While only about <a href="https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095545945;jsessionid=F1D6CE7E04A3DF20C48A6949F4A2F683#:%7E:text=C3%20plants%20make%20up%20over,let%20in%20more%20carbon%20dioxide">5%</a> of all plants have C4 photosynthesis, some of them are important grass species, such as:</p>
<ul>
<li><p>bermuda grass</p></li>
<li><p>buffalo grass</p></li>
<li><p>paspalum</p></li>
<li><p><a href="https://www.anbg.gov.au/gnp/interns-2004/themeda-triandra.html">kangaroo grass</a></p></li>
<li><p>couch grass, and </p></li>
<li><p>zoysia grass.</p></li>
</ul>
<p>So if your lawn is sown with one of these grasses, you will definitely see a slowdown in winter, when they become <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC167095/">dormant</a>. </p>
<p>Their leaves tend to turn from bright green to a dull pale green or even yellow. Their growth slows quickly and dramatically in early autumn as the light levels fall, temperatures cool and chlorophyll production starts to decline.</p>
<p>The upside, of course, is they usually grow very well when the weather warms up again.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trees-can-be-weeds-too-heres-why-thats-a-problem-182599">Trees can be weeds too – here's why that's a problem</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/206616/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Different grasses respond to and cope with winter in different ways.Gregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2073752023-06-12T15:00:40Z2023-06-12T15:00:40ZColonialism has shaped scientific plant collections around the world – here’s why that matters<figure><img src="https://images.theconversation.com/files/531254/original/file-20230611-84609-t8xxx2.jpg?ixlib=rb-1.1.0&rect=36%2C0%2C4813%2C3228&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Digitizing plants preserved in the herbarium at La Sapienza University in Rome.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/rome-la-sapienza-museum-complex-herbarium-museum-the-news-photo/1401716985">Mimmo Frassineti/AGF/Universal Images Group via Getty Images</a></span></figcaption></figure><p>Some of the <a href="https://theculturetrip.com/north-america/usa/articles/the-15-most-visited-museums-in-the-world/">world’s most popular museums</a> are natural history collections: Think of dinosaur fossils, gemstones and preserved animals. Herbaria – collections of pressed, dried plant specimens – are a less-known but important type of natural history collection. There are some <a href="https://sweetgum.nybg.org/science/ih/">400 million botanical specimens</a> stored across over 3,500 herbaria around the world, but most are not widely publicized and rarely host public exhibits. </p>
<p>I study <a href="https://scholar.google.com/citations?user=BF2WtIYAAAAJ&hl=en">biodiversity and global change</a>, and these collections have fueled my work. My collaborators and I have used herbarium collections to study how <a href="https://doi.org/10.1098/rstb.2017.0394">flowering times respond to changes in climate</a>, how dispersal traits and environmental preferences <a href="https://doi.org/10.1111/mec.13227">affect the likelihood that plants will become invasive</a>, and <a href="https://doi.org/10.1038/s41586-021-03876-7">how fires affect tropical biodiversity</a>. </p>
<p>I have had easy access to specimens from every corner of the world, but most researchers are not as lucky. This is partly because herbaria as we know them today are largely a European creation. And like other natural history collections, many of them grew as imperial powers expanded their colonial empires and <a href="https://digpodcast.org/2018/04/29/natural-history-museums/">amassed all kinds of resources</a> from their colonies. Today, over 60% of herbaria and 70% of specimens are located in developed countries with colonial histories. </p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/6XV5DyOTlV/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>My colleagues and I wanted to understand how many herbarium specimens <a href="https://www.nature.com/articles/s41562-023-01616-7">are not where the plants originated</a> and are housed in former colonizing countries instead. Our international team of researchers from herbaria on every continent analyzed over 85 million plant specimen records from the <a href="https://www.gbif.org/">Global Biodiversity Information Facility</a>, the largest online repository of biodiversity data, and also surveyed physical herbarium collections across the world. </p>
<p>We found that many former colonial powers have more plant diversity in their herbarium cabinets than they do in nature. Our data suggest that this is not the case, however, for former colonies, whose herbaria often house fewer plant species in their collections than are found naturally in the region. This disparity can limit former colonies’ capacity for botanical research. </p>
<h2>A persistent colonial legacy</h2>
<p>Herbaria are centers of botanical discovery and research, and are critical for understanding the diversity of plants and fungi around the world. The specimens they hold were originally collected to document and classify species. Today scientists use them for additional purposes, such as reconstructing plant evolutionary history, tracking pollution trends and identifying potential new drugs. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/bKcRUloQm0M?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Researchers at the Royal Botanic Garden in Edinburgh explain how the collection supports biodiversity research and conservation projects around the world.</span></figcaption>
</figure>
<p>Botany was <a href="https://www.plantsandculture.org/botanical-gardens-and-colonialism">the science par excellence of colonial empires</a>. Botanists moved numerous living and preserved plant specimens to institutions in colonizing nations which sought to exploit their colonies’ biological resources. </p>
<p>For instance, physician and naturalist <a href="https://www.britishmuseum.org/about-us/british-museum-story/sir-hans-sloane">Hans Sloane</a>, often credited as the inventor of chocolate milk, acquired numerous plant specimens from overseas colonies via his connections with the slave trade. His collections formed the basis of Britain’s <a href="https://www.nhm.ac.uk/">Natural History Museum</a>. Well-known scientists, including <a href="https://www.smithsonianmag.com/science-nature/charles-darwin-botanist-orchid-flowers-validate-natural-selection-180971472/">Charles Darwin</a> and <a href="https://www.nhm.ac.uk/our-science/departments-and-staff/library-and-archives/collections/linnaean-collection.html">Carl Linnaeus</a> and their disciples, relocated large numbers of plants from across the globe to European museums and collections.</p>
<p>Our analyses of online specimen records suggest that botanical collection trends over the past four centuries have been shaped by colonialism. Even though overt colonialism ended after World War II, specimens have largely continued to move from Africa, Asia and South America to institutions in Europe and North America, with a few exceptions.</p>
<p>Similarly, when we examined physical herbarium collections, we found that those in developed nations in the Global North that were former colonizers housed a higher proportion of internationally collected specimens on average. Herbaria in the U.S. and several European nations house specimens of over twice the number of species that naturally occur in these nations. </p>
<p>In nature, plant diversity is typically greatest in regions near the equator and decreases northward and southward toward the poles. Our data suggest that centuries of colonialism had the opposite effect: Plant specimens were moved away from countries with high natural plant diversity to collections in countries where fewer plant species occur naturally. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dried plant with four large leaves and a flower, captioned with a scientific description." src="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=841&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=841&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=841&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1057&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1057&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1057&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Ruellia tubiflora</em>, a tropical plant collected from Venezuela in 2001, preserved in the collection of Chicago’s Field Museum of Natural History.</span>
<span class="attribution"><a class="source" href="https://plantidtools.fieldmuseum.org/en/rrc/catalogue/322388">Field Museum</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The digital divide</h2>
<p>As herbaria digitize their specimens and share data online, they are becoming somewhat more decentralized and democratic. Open-access data repositories, such as <a href="https://www.gbif.org/">the Global Biodiversity Information Facility</a>, allow researchers from around the world to query aggregated specimen metadata and images over the internet. This reduces the need to ship fragile specimens over long distances, and to take extensive and costly research trips. </p>
<p>But digitization requires large investments in equipment and personnel, which small institutions and developing countries often can’t afford. Stable internet connections are not always widely available in developing countries either. Further, our survey of herbaria indicates that digitization still has a long way to go. </p>
<p>We estimated that in general, fewer than 30% of physical collections have information online that at least describes when and where specimens were collected, and fewer than 10% have digital images available online. Most herbaria that responded to our inquiries were located in developed countries, so these figures probably overestimate the state of specimen digitization. The disparity in access to herbarium collections exists in the digital realm as well.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1654573880160157696"}"></div></p>
<h2>Making global plant collections more inclusive</h2>
<p>Many natural history museums and other cultural institutions are working now to <a href="https://www.sapiens.org/culture/museum-restitution/">address their colonial legacies</a>. This often includes acknowledging items in their collections that were acquired <a href="https://www.smithsonianmag.com/smart-news/harvard-museum-apologizes-for-owning-700-hair-samples-of-native-american-children-180981135/">unethically</a> or <a href="https://projectarchaeology.org/2021/03/19/modern-issues-in-archaeology-the-illegal-artifact-trade/">illegally</a>, and sometimes returning them to their original sources. But botanical collections have received less attention, maybe because few of them offer public displays. </p>
<p>Our study shows that there is a large disparity between where plant diversity naturally exists and where it is artificially housed and cataloged. As a result, many countries rely on botanical knowledge and resources housed outside of their own borders. </p>
<p>My colleagues and I believe that herbaria should be part of the ongoing movement to decolonize cultural institutions, natural history museums and related scientific practices. Key steps would include:</p>
<p>– Openly acknowledging the colonial legacy of herbarium collections, and communicating their history;</p>
<p>– Improving access to the vast information held in herbaria worldwide; and</p>
<p>– Building capacity in previously colonized countries by sharing knowledge and resources for contributing to research. These could include, for instance, supporting the local collection and study of plant diversity by providing training for local scientists. </p>
<p>In our view, the science that comes from botanical collections is globally relevant, so access to these resources should be within reach of the global community. Herbarium collections are critical to modern understanding of the world’s plants, and they have played key roles in numerous scientific discoveries and advances. Imagine how much more would be possible if these invaluable resources were available to all.</p><img src="https://counter.theconversation.com/content/207375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Park does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The colonial era profoundly shaped natural history museums and collections. Herbaria, which are scientists’ main source of plant specimens from around the world, are no exception.Daniel Park, Assistant Professor of Biological Sciences, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2069882023-06-05T20:03:48Z2023-06-05T20:03:48ZThe world’s first flowers were pollinated by insects<figure><img src="https://images.theconversation.com/files/529932/original/file-20230604-129052-ofkmgy.jpeg?ixlib=rb-1.1.0&rect=850%2C1047%2C2161%2C1706&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Ruby E Stephens</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Plants existed on Earth for hundreds of millions of years before the first flowers bloomed. But when flowering plants did evolve, more than 140 million years ago, they were a huge evolutionary success.</p>
<p>What pollinated these first flowering plants, the ancestor of all the flowers we see today? Was it insects carrying pollen between those early flowers, fertilising them in the process? Or perhaps other animals, or even wind or water?</p>
<p>The question has been a tricky one to answer. However, in <a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18993">new research</a> published in New Phytologist, we show the first pollinators were most likely insects. </p>
<p>What’s more, despite some evolutionary detours, around 86% of all flowering plant species throughout history have also relied on insects for pollination.</p>
<h2>How to move pollen</h2>
<p>The timing of the evolution of the first flowering plants is still <a href="https://doi.org/10.1093/jxb/erac130">a matter of debate</a>. However, their success is inarguable.</p>
<p>Around 90% of modern plants – some 300,000-400,000 species – are flowering plants, or what scientists call angiosperms. To reproduce, these plants make pollen in their flowers, which needs to be transferred to another flower to fertilise an ovule and produce a viable seed. </p>
<p>Small and highly mobile, insects can be highly effective pollen transporters. Indeed, recent <a href="http://doi.org/10.1016/j.tree.2023.03.008">research on fossil insects</a> shows some insects may have been pollinating plants even before the first flowers evolved.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=196&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=196&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=196&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=246&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=246&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529933/original/file-20230604-25-bz6uu0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=246&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Flowers have evolved every sort of shape and colour to get themselves pollinated.</span>
<span class="attribution"><span class="source">Ruby E Stephens</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Most of today’s flowering plants rely on insects for pollination. The plant’s flowers have evolved to attract insects via colour, scent and even sexual mimicry, and most reward them with nectar, pollen, oils or other types of food, making the relationship beneficial to both parties.</p>
<p>Some flowers, however, rely on other means to transport their pollen, such as vertebrate animals, wind or even water. </p>
<p>Which kind of pollination evolved first? Were insects there at the beginning, or were they a later “discovery”? </p>
<p>While <a href="https://doi.org/10.1073/pnas.0707989105">early evidence</a> suggests it was probably insects, until now this has never been tested across the full diversity of flowering plants – their full evolutionary tree.</p>
<h2>A family tree</h2>
<p>To find an answer, we used a “<a href="https://doi.org/10.1038/s41559-020-1241-3">family tree</a>” of all families of flowering plants, sampling more than 1,160 species and reaching back more than 145 million years.</p>
<p>This tree shows us when different plant families evolved. We used it to map backwards from what pollinates a plant in the present to what might have pollinated the ancestor of that plant in the past.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=597&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=597&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=597&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=750&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=750&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529930/original/file-20230604-80115-8wjczk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=750&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The evolutionary tree for all flowering plant families shows when wind, water and vertebrate pollination evolved from insect pollination.</span>
<span class="attribution"><span class="source">Ruby E Stephens</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We found insect pollination has been overwhelmingly the most common method over the history of flowering plants, occurring around 86% of the time. And our models suggest the first flowers were most likely pollinated by insects. </p>
<h2>Birds, bats and wind</h2>
<p>We also learned about the evolution of other forms of pollination. Pollination by vertebrate animals, such as birds and bats, small mammals and <a href="https://doi.org/10.1086/593050">even lizards</a>, has evolved at least 39 times – and reverted back to insect pollination at least 26 of those times.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A microscope photo showing tiny grass flowers." src="https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=563&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=563&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=563&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=708&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=708&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529929/original/file-20230604-15-o6v4bp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=708&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wind pollinated flowers are often very small and plain, like these grass flowers which can only be seen clearly under a microscope.</span>
<span class="attribution"><span class="source">Ruby E Stephens</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Wind pollination has evolved even more often: we found 42 instances. These plants rarely go back to insect pollination.</p>
<p>We also found wind pollination evolved more often in open habitats, at higher latitudes. Animal pollination is more common in closed-canopy rainforests, near the equator.</p>
<h2>What kind of insects were the first pollinators?</h2>
<p>If you think of a pollinating insect, you probably imagine a bee. But while we don’t know exactly what insects pollinated the first flowering plants, we can be confident they weren’t bees.</p>
<p>Why not? Because most evidence we have indicates bees didn’t evolve until <a href="https://doi.org/10.1016/j.tplants.2022.04.004">after the first flowers</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/flies-like-yellow-bees-like-blue-how-flower-colours-cater-to-the-taste-of-pollinating-insects-167111">Flies like yellow, bees like blue: how flower colours cater to the taste of pollinating insects</a>
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</em>
</p>
<hr>
<p>So what do we know about the pollinators of the first flowering plants? Well, some early flowers have been preserved as fossils – and most of these are very small.</p>
<p>The first flower pollinators must have been quite small, too, to poke around in these flowers. The most likely culprits are some kind of small fly or beetle, maybe even a midge, or some extinct types of insects that have long disappeared.</p>
<p>If only we had a time machine we could go back and see these pollinators in action - but that will require a lot more research!</p><img src="https://counter.theconversation.com/content/206988/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ruby E. Stephens receives funding from the Australian Government's Research Training Program. </span></em></p><p class="fine-print"><em><span>Hervé Sauquet receives funding from the Australian Research Council and Australian Research Data Commons. </span></em></p><p class="fine-print"><em><span>Lily Dun received funding from Australian Research Data Commons. </span></em></p><p class="fine-print"><em><span>Rachael Gallagher receives funding from The Australian Research Council. </span></em></p><p class="fine-print"><em><span>Will Cornwell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research suggests insects have pollinated flowers since the pollen-bearing blooms first evolved more than 140 million years ago.Ruby E. Stephens, PhD Candidate, School of Natural Sciences, Macquarie UniversityHervé Sauquet, Senior Research Scientist, Royal Botanic Gardens Sydney and Adjunct Associate Professor, UNSW SydneyLily Dun, Research Assistant, UNSW SydneyRachael Gallagher, Associate Professor, Hawkesbury Institute for the Environment, Western Sydney UniversityWill Cornwell, Associate Professor in Ecology and Evolution, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2052912023-06-02T02:20:07Z2023-06-02T02:20:07ZNative raspberries, limes and geraniums: how did these curious plants end up in Australia?<figure><img src="https://images.theconversation.com/files/526418/original/file-20230516-29-uk5gcm.jpg?ixlib=rb-1.1.0&rect=61%2C38%2C5102%2C3700&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>While plants can’t walk, they can certainly travel. Some species have travelled vast distances over millennia, moving by different and varied modes. </p>
<p>Some found new habitats when the continent they were riding on slowly crashed into another. Others went on perilous ocean going journeys – think of coconuts washing up on new island shores. Others still have been carried as seeds by birds or other animals – including us. </p>
<p>Many have now become local, endemic to their region of Australia. Some may surprise you. </p>
<h2>Native nuts – how macadamia trees began</h2>
<p>Early in the age of jet aeroplanes, flying to America meant a stop-over in Hawaii to refuel. Here, many Australians tasted macadamia nuts for the first time and probably assumed they were a local delicacy. Imagine their surprise at discovering the truth. Hawaii’s macadamia industry began when a few nuts were <a href="https://www.smithsonianmag.com/smart-news/most-worlds-macadamias-may-have-originated-single-australian-tree-180972349">sent from</a> Australia in the 1880s. </p>
<p>Of course, this was not news to Australia’s First Nations people, many of whom had enjoyed macadamia nuts for millennia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="macadamia nuts" src="https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526421/original/file-20230516-23-gp5zr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Macadamia nuts first gained notice in Hawaii – but they’re Australian as can be.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>There are <a href="https://www.wildmacadamias.org.au/rare-macadamias/the-four-macadamias">four species</a> of Macadamia, of which two are the most important nut producers, namely <em>Macadamia integrifolia</em> and <em>M
. tetraphylla</em>. All species belong to the <em>Proteaceae</em> family, meaning they are related to banksias, grevilleas and proteas. </p>
<p>This family connection reveals the genus has a long evolutionary history, dating back about 100 million years. Macadamias travelled with the continent of Australia as it split off from Antarctica and South America. </p>
<p>In their natural habitat across northern New South Wales and southern Queensland, these subtropical trees can reach heights of 25 metres. But even though they are now widely farmed, they’re <a href="https://www.wildmacadamias.org.au/rare-macadamias/threats-facing-wild-macadamias/">actually threatened</a> in the wild – and may be further threatened by climate change. </p>
<h2>Oranges, lemons – and native citrus?</h2>
<p>Many of us are fond of tart and tasty citrus – oranges from southern China, lemons probably from northern India. All the world’s citrus trees stem from an ancestor species which grew in the foothills of the Himalayas, according to <a href="https://www.nature.com/articles/nature25447">DNA evidence</a>. Over time, these trees spread out and new species split off. Eventually, about 8–10 million years ago, they arrived in Australia. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-tools-and-medicine-5-native-plants-that-illuminate-deep-aboriginal-knowledge-145240">Food, tools and medicine: 5 native plants that illuminate deep Aboriginal knowledge</a>
</strong>
</em>
</p>
<hr>
<p>The most well known is the finger lime, <em>C. australasica</em>, with tiny globes spilling out of the fruit like citrus caviar. But there are others, like the Australian lime, <em>Citrus australis</em> and the desert lime <em>C. glauca</em>. Like many citrus, they can be prickly customers with long painful spines. While most are shrubs and small trees, the Australian lime can <a href="https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2900219">reach heights</a> of 20 metres.</p>
<h2>Native raspberries</h2>
<p>In recent years, the <a href="https://vicflora.rbg.vic.gov.au/flora/taxon/bc19413d-6b07-4c94-84ee-4b5fef7e2f98">native raspberry</a>, <em>Rubus probus</em>, has achieved celebrity status as a prickly, quick growing bramble with a good fruit. </p>
<p>But like its relative, the blackberry, <em>Rubus fruticosus</em>, you have to work hard to get fruit and rarely come away unscathed. </p>
<p>That’s why it was <a href="https://www.abc.net.au/news/2021-10-23/thornless-native-raspberries-native-food-game-changer/100546938">big news</a> when a thornless specimen was found and propagated. This will make a big difference to the cultivation of our native raspberry. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Native raspberry" src="https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526408/original/file-20230516-21-wo5rkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Our native raspberry is becoming popular.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>So how did Australia come to have raspberries? It seems likely their ancestors migrated from North America towards Europe and Asia between 10 and 15 million years ago and eventually made it to Oceania. </p>
<p>Exactly how the genus <em>Rubus</em> made it to Australia is unknown, but the <a href="https://www.frontiersin.org/articles/10.3389/fpls.2019.01615/full">most likely pathway</a> is a few seeds stuck to the feathers of a migrating bird. It could have happened as recently as a few hundred thousand years ago. </p>
<h2>Native geraniums? It’s true</h2>
<p>I associate geraniums with my maternal grandmother, who had the most magnificent red geraniums along her back fence. Family folklore had it they were cuttings from a prize winner at a major horticultural exhibition – and I believe it.</p>
<p>While we associate garden geraniums with Europe, they’re actually African and <a href="https://www.gapswa.org.au/pelargonium-history.html">only arrived</a> in Europe in the 17th century. </p>
<p>But while we all know these geraniums, Australia has its own species. That fact still amazes me after decades of studying plants. </p>
<p>But first, let’s clear up the debate over names. In the 17th century, geraniums and closely-related pelargoniums were grouped together in a single genus. But early in the 18th century, Charles LeHeritier – the botanist who <a href="http://theconversation.com/stringybark-is-tough-as-boots-and-gave-us-the-word-eucalyptus-100528">first described</a> eucalypts – divided them and there has been confusion ever since. </p>
<p>The easiest way of telling them apart is that geraniums have five petals of the same size and shape but pelargoniums have two larger petals and three smaller ones. </p>
<p>Most of the Australian native plants commonly called geraniums are in fact pelargoniums. You may have stumbled across <em>Pelargonium australe</em>, the most common of our seven species, which is <a href="https://resources.austplants.com.au/plant/pelargonium-australe">spread across</a> much of southern Australia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="australian pelargonium" src="https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526406/original/file-20230516-15-12i7wp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Native geranium? The pelargonium australe is the native plant most commonly thought of as a geranium.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Pelargonium_australe_%28Geraniaceae%29_flower.JPG">Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Native orchids: from flying ducks to the Queen of Sheba</h2>
<p>There’s something about orchids. In the 19th century, so many Europeans went mad for their flowers that the name “orchidelirium” was coined. </p>
<p>We have some of the most iconic orchids as natives, such as the remarkable flying duck orchid and the stunning Queen of Sheba. Our 1800 species <a href="https://www.frontiersin.org/articles/10.3389/fpls.2022.912089/full">mostly grow</a> in our tropical and subtropical areas. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="flying duck orchid" src="https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526404/original/file-20230516-23-itjdjz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Australia’s flying duck orchid (Caleana major) is world-famous for its resemblance.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Some orchids <a href="https://ecos.csiro.au/orchid-evolution/">can be traced</a> back to the last years of Gondwana. But curiously, we also have tropical species which must have island hopped from Papua New Guinea and Indonesia more recently. </p>
<p>That’s only the start of our surprising plants. We have native tamarinds, native rivermint, and a <a href="https://anpsa.org.au/plant_profiles/rhododendron-lochiae/">native rhododendron</a>. </p>
<p>And did you know that cloves <a href="https://theconversation.com/lets-show-a-bit-of-love-for-the-lillipilly-this-humble-plant-forms-the-worlds-largest-genus-of-trees-and-should-be-an-australian-icon-191080">come from</a> an Indonesian species of lilly pilly? This species is related to Australian lilly pillies, a genus which evolved as the final fragmentation of Gondwana occurred about 65 million years ago. They rapidly diversified and there are now over 1000 species.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="queen of sheba orchid" src="https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=550&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=550&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=550&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=692&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=692&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526405/original/file-20230516-29-fqdfj8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=692&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Eastern Queen of Sheba orchid is rightly famous.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Plants move slowly. But they move much more than you’d expect. Their success has enriched the biodiversity and novelty of our ecosystems in surprising ways. As for me, I love an Australian macadamia nut – and I’ll always love those imported red geraniums.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lets-show-a-bit-of-love-for-the-lillipilly-this-humble-plant-forms-the-worlds-largest-genus-of-trees-and-should-be-an-australian-icon-191080">Let's show a bit of love for the lillipilly. This humble plant forms the world's largest genus of trees – and should be an Australian icon</a>
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</p>
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<img src="https://counter.theconversation.com/content/205291/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Whether riding on the feathers of birds or evolving on Gondwana, Australia’s plants got here in very different waysGregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2057202023-05-18T14:37:02Z2023-05-18T14:37:02ZDecolonize your garden: This long weekend, dig into the complicated roots of gardening — Listen<p>The May long weekend is the unofficial start of summer. And for those of you with home gardens or access to community space, this is the weekend to dust off your gardening tools and visit the garden centre for the growing season ahead.</p>
<p>As we approach the start of gardening season, it’s good time to ask some questions about its origins.</p>
<p>Whether you plan to get marigolds, plant a vegetable garden or create a pollinator patch — all gardens have complicated roots. </p>
<p>In fact, the practice of gardening is <a href="https://www.architectural-review.com/essays/the-coloniality-of-planting">deeply tied to colonialism</a> — from the <a href="https://www.noemamag.com/the-long-shadow-of-colonial-science">formation of botany as a science</a>, to the <a href="https://www.nature.com/articles/s41559-022-01865-1">spread of seeds, species and knowledge.</a> </p>
<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/92c92d2a-9628-4da6-9b3f-8bf5ec67d7cf?dark=true"></iframe>
<p><em><a href="https://dont-call-me-resilient.simplecast.com/episodes/decolonize-your-garden-this-long-weekend-visit-the-complicated-roots-of-gardening-listen">In this episode of Don’t Call Me Resilient</a>, we explore the complicated roots of the garden, including who gets to garden. We also discuss practical tips about what to plant with an eye to Indigenous knowledge. We speak with researcher Jacqueline L. Scott and also chat with community activist, Carolynne Crawley, who leads workshops that integrate Indigenous teachings into practice.</em></p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=826&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=826&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=826&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1039&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1039&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526840/original/file-20230517-5572-g2q2yt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1039&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Watercolor illustration of Tulipa sylvestris in I Cinque libri di piante.</span>
<span class="attribution"><span class="source">Pietro Antonio Michiel, Venice ca. 1550–1576, Biblioteca Nazionale Marciana.</span></span>
</figcaption>
</figure>
<h2>Coveted tulips</h2>
<p>Some of the most recognizable plants today, such as <a href="https://www.smithsonianmag.com/history/there-never-was-real-tulip-fever-180964915/">tulips</a>, are the result of early colonial conquests. Originally found growing wild in the valleys where current China and Tibet meet Afghanistan and Russia, tulips were first cultivated in Istanbul as early as 1055. </p>
<p>Later, after they were hybridized and commodified by the Dutch, they became highly coveted status symbols because of their gorgeous, but fleeting, blooms. </p>
<p>Exploratory botanical voyages by colonial European powers were integral to the expansion of empire. These trips fueled the big business of collecting global plant samples and also led to the emergence of botany as a scientific discipline. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=585&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=585&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526841/original/file-20230517-21-yooz26.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=585&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">227 figures of plant anatomical segments with descriptive text. Botany. Plant anatomy. Plant morphology. Plants. Roots (Botany). Roots (Botany) – Morphology. Roots (Botany) – Anatomy. Rootstocks. Tubers. Leaves. Leaves – Morphology. Flowers – Morphology. Flowers. Fruit – Morphology. Bulbs (Plant anatomy). Plants – Variation. Botany – France. Stems (Botany).</span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>Botanical gardens served as labs</h2>
<p>Botanical gardens played a key role, serving as the laboratories where plant specimens were organized, ordered and named. <a href="https://doi.org/10.1016/j.fsisyn.2021.100196">“Scientific objectivity”</a> asserted a Eurocentric point of view, disrupting and displacing Indigenous Knowledge and ecological practices. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=481&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=481&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526842/original/file-20230517-12607-80m0ex.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=481&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A 1913 illustrated depiction of African American people picking cotton.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:CottonpickHoustonWhere17.png">Jerome H. Farbar: 'Houston: Where Seventeen Railroads Meet the Sea.' Page 31/40, 'Cotton Pickers'</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The movement and transfer of plants around the world went hand in hand with the transportation of people to provide a labour force, through slavery and indentured servitude. </p>
<p>The plantation system cleared out local ecosystems and replaced traditional farming methods with growing cash crops — like <a href="https://www.nytimes.com/interactive/2019/08/14/magazine/sugar-slave-trade-slavery.html">sugar-cane</a>, <a href="https://thecorrespondent.com/222/the-history-of-tea-is-darker-than-a-builders-brew">tea</a> and <a href="https://www.vox.com/identities/2019/8/16/20806069/slavery-economy-capitalism-violence-cotton-edward-baptist">cotton.</a> These were products meant for European curiosities, markets and profit and not for the local populations.</p>
<h2>Plant and racial hierarchies</h2>
<p>This colonial system of <a href="https://open.oregonstate.education/cultivatedplants/chapter/colonialagriculture/">organizing agriculture</a> laid the groundwork for <a href="https://www.sapiens.org/biology/race-scientific-taxonomy/">categorizing people</a> in a similar way, establishing a social hierarchy which dehumanized non-Europeans, helping justify slavery and Indigenous genocide, and eventually leading to racial categories.</p>
<p>This history has shaped our current relationships to the land, and our gardens. It also informs beliefs about land ownership and access; who has a right to enjoy the land, versus who is expected to be working on it. Who has the literal and figurative space and freedom to garden?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=435&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=435&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=435&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=547&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=547&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526848/original/file-20230517-13420-luw1sy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=547&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On the left is a lawn (Stephen Cobb/Unsplash) and on the right is a native plant garden in Streeterville, Chicago (Shutterstock).</span>
</figcaption>
</figure>
<h2>Shifting attitudes</h2>
<p>But the soil is shifting. There is a growing shift away from <a href="https://www.theglobeandmail.com/canada/article-is-it-time-to-decolonize-your-lawn/">the colonial status symbol of the lawn</a> and <a href="https://chatelaine.com/living/quiet-quitting-garden/">manicured gardens</a>, in favour of <a href="https://broadview.org/lorraine-johnson-interview/">pollinator-friendly</a> <a href="https://www.nytimes.com/2022/07/13/realestate/why-some-of-your-annuals-should-be-native-plants.html">native plants</a>. </p>
<p>There is also a growing understanding that <a href="https://broadview.org/grandfather-teachings-gardening/">centuries-old Indigenous land-based knowledge</a> and practices — like <a href="https://www.theguardian.com/us-news/2019/nov/21/wildfire-prescribed-burns-california-native-americans">controlled burns</a> — can help manage wildfires, and foster a more resilient landscape.</p>
<p>With concerns about our climate crisis growing, one of the possible avenues for <a href="https://theconversation.com/how-urban-gardens-can-boost-biodiversity-and-make-cities-more-sustainable-162810">creating more sustainable cities may very well lie in our gardens</a>.</p>
<p>Could we have an impact simply by thinking a little differently about the seeds we sow and the “weeds” we pull?</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=993&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=993&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=993&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1248&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1248&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526851/original/file-20230517-10717-ww5ofa.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1248&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Monarch butterfly on purple coneflowers.</span>
<span class="attribution"><span class="source">Jeffrey Hamilton/Unsplash</span></span>
</figcaption>
</figure>
<h2>Listen and Follow</h2>
<p>You can listen to or follow <em>Don’t Call Me Resilient</em> on <a href="https://podcasts.apple.com/ca/podcast/dont-call-me-resilient/id1549798876">Apple Podcasts</a>, <a href="https://podcasts.google.com/feed/aHR0cHM6Ly9mZWVkcy5zaW1wbGVjYXN0LmNvbS9qZFg0Ql9DOA">Google Podcasts</a>, <a href="https://open.spotify.com/show/37tK4zmjWvq2Sh6jLIpzp7">Spotify</a> or <a href="https://dont-call-me-resilient.simplecast.com">wherever you listen to your favourite podcasts</a>. </p>
<p><a href="mailto:DCMR@theconversation.com">We’d love to hear from you</a>, including any ideas for future episodes. Join The Conversation on <a href="https://twitter.com/ConversationCA">Twitter</a>, <a href="https://www.facebook.com/TheConversationCanada">Facebook</a>, <a href="https://www.instagram.com/theconversationdotcom/">Instagram</a> and <a href="https://www.tiktok.com/@theconversation">TikTok</a> and use #DontCallMeResilient.</p>
<h2>Resources</h2>
<p><a href="https://www.nationalobserver.com/2021/01/29/news/tiffany-traverse-rare-indigenous-seed-project">Tiffany Traverse on seeds and their endless power to give, heal and grow</a> - <em>Canada’s National Observer</em></p>
<p><a href="https://www.architectural-review.com/essays/the-coloniality-of-planting">The coloniality of planting: legacies of racism and slavery in the practice of botany</a> - <em>The Architectural Review</em></p>
<p><a href="https://www.noemamag.com/the-long-shadow-of-colonial-science/">The Long Shadow Of Colonial Science</a> - <em>Noema Magazine</em></p>
<p><a href="https://www.theglobeandmail.com/canada/article-is-it-time-to-decolonize-your-lawn/">Is it time to decolonize your lawn?</a> - <em>Globe and Mail</em></p>
<p><a href="https://turtleprotectors.com">Turtle Protectors</a> in Toronto’s High Park</p>
<p><a href="https://gardeningoutloud.substack.com/p/guest-episode-1-spring-joy-with-ateqah">Spring joy with Ateqah Khaki</a> - <em>Gardening Out Loud</em></p>
<h2>From the archives - in The Conversation</h2>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-colonial-past-of-botanical-gardens-can-be-put-to-good-use-104786">How the colonial past of botanical gardens can be put to good use</a>
</strong>
</em>
</p>
<hr>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/director-of-science-at-kew-its-time-to-decolonise-botanical-collections-141070">Director of science at Kew: it's time to decolonise botanical collections</a>
</strong>
</em>
</p>
<hr>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-shortage-of-native-seeds-is-slowing-land-restoration-across-the-us-which-is-crucial-for-tackling-climate-change-and-extinctions-199049">A shortage of native seeds is slowing land restoration across the US, which is crucial for tackling climate change and extinctions</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526355/original/file-20230515-24343-lszaxe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An aerial view of small green seedlings in pots.</span>
<span class="attribution"><span class="source">Markus Spiske PG/Unsplash</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/205720/count.gif" alt="The Conversation" width="1" height="1" />
As we approach the start of gardening season, it’s a good time to ask some questions about what to plant and who gets to plant.Vinita Srivastava, Host + Producer, Don't Call Me ResilientAteqah Khaki, Associate Producer, Don't Call Me ResilientLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2042912023-05-04T15:48:23Z2023-05-04T15:48:23ZLearn to think like a plant: five questions to think about if you want to keep your houseplants healthy<figure><img src="https://images.theconversation.com/files/524044/original/file-20230503-27-1ecqyl.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5659%2C3758&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many people struggle to keep their houseplants alive.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-upset-sad-woman-holding-dried-2206537809">Okrasiuk/Shutterstock</a></span></figcaption></figure><p><em>You don’t drown by falling into the water; you drown by staying there (Edwin Louis Cole).</em> </p>
<p>I’d say most potted orchid deaths arise from drowned roots. Conversely, I’ve seen people desiccate cacti believing they don’t need water. True, I scarcely water mine for six months in the year, but in high summer I water them weekly. My potted orchids instead enjoy a good shower all year round. </p>
<p>Houseplants all have their likes and dislikes. But once you know the rules of thumb, there are few homes in which you can’t grow a plant well.</p>
<p>I’m a botanist and my work takes me all over the world in pursuit of plants. Seeing a plant in the wild helps you understand how it is adapted to a given environment and how you can recreate that environment in your home. When I bring a new plant into my home, I ask: how would you grow in nature? And where would you be happiest? </p>
<p>The roots of <a href="https://www.rhs.org.uk/plants/phalaenopsis/growing-guide"><em>Phalaenopsis</em></a> (a popular indoor orchid) cling to tree branches in the wild. An orchid’s roots need air around them and they cannot withstand sitting in water. But showering the orchid regularly and allowing the water to drain freely mimics a tropical rainstorm, so it suits the plant perfectly.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The author with a wild bird's-nest-fern in the jungle." src="https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/524079/original/file-20230503-17-5ogyn2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The author with a wild bird’s-nest-fern in the jungle.</span>
<span class="attribution"><span class="source">Chris Thorogood</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>In a rainforest in the Philippines, I once saw an <a href="https://www.rhs.org.uk/plants/912/alocasia/details"><em>Alocasia</em></a> (a popular foliage plant with striking veins) growing just metres from a <a href="https://www.rhsplants.co.uk/plants/_/asplenium-nidus/classid.2000028174/">bird’s-nest-fern</a> (another houseplant with glossy green fronds). </p>
<p>The <em>Alocasia</em> was growing on the shady forest floor and the bird’s-nest-fern was sprouting from the fork of a tree above it. The <em>Alocasia</em> likes filtered light, and much like orchids, the bird’s-nest-fern enjoys good drainage.</p>
<p>To grow a houseplant well, you must learn to think like a plant. So, here are my top tips for keeping your houseplants healthy.</p>
<h2>1. Where should your plant go?</h2>
<p>There’s a bewildering variety of plants available now that <a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1002/ppp3.10257">houseplants are taking over our homes</a>. But it’s good to remember the old adage “right plant, right place”. </p>
<p>It’s no good growing a cactus in a shady corner – it simply won’t work. Start with the conditions you have in your home and go from there.</p>
<p>A bright, humid place such as a kitchen or bathroom windowsill is perfect for most tropical or subtropical houseplants. <a href="https://www.rhs.org.uk/plants/types/cacti-succulents">Cacti and succulents</a>, which are adapted to live in deserts, instead need as much sunlight as possible all year round.</p>
<p>Many houseplants also thrive on a spell outdoors – typically from June to August. I place my succulents outside against a warm wall during summer. </p>
<p>But avoid moving a plant into full sun too quickly. Even a <a href="https://www.rhs.org.uk/plants/banana/growing-guide">banana plant</a>, which flourishes under tropical sun, can scorch if you change its conditions too abruptly.</p>
<figure class="align-center ">
<img alt="An Alocasia growing in the Philippines." src="https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/523886/original/file-20230502-4164-4e90m3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An Alocasia growing in the Philippines.</span>
<span class="attribution"><span class="source">Chris Thorogood</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>2. When and how should you water?</h2>
<p>Plants generally prefer liberal watering in the summer months when they’re growing actively, and far less in the winter. Taking this to extremes, I keep cacti and succulents in an unheated greenhouse and do not water them at all from October to April. Desert nights are cold, so many of these plants are surprisingly cold-hardy when dry. </p>
<p>By contrast, I keep a large <a href="https://www.rhs.org.uk/plants/140276/monstera/details">Swiss cheese plant</a> in a shady corner, and water it fortnightly in winter and weekly in summer. Like people, it thrives on routine. </p>
<p>But even then, it’s important to water all of your plants with lukewarm – and never cold – water. This enhances absorption and avoids temperature-shock. Using body temperature (37°C) water is a good rule of thumb.</p>
<p>Carnivorous plants, such as the <a href="https://www.rhs.org.uk/plants/5893/i-dionaea-muscipula-i/details">Venus flytrap</a>, that derive their nutrients from trapping and consuming insects instead need rain. They hate tap water.</p>
<figure class="align-center ">
<img alt="The Venus flytrap plant." src="https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/523887/original/file-20230502-22-eguhi6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Venus flytrap plant.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/venus-flytrap-venuss-dionaea-muscipula-carnivorous-1180846009">yakonstant/Shutterstock</a></span>
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<h2>4. Should you feed them?</h2>
<p>Most houseplants will plod along with little or no supplementary plant food (such as a liquid fertiliser). But some, including foliage plants like <a href="https://www.rhs.org.uk/plants/95720/ficus-elastica/details">rubber figs</a> and Swiss cheese plants, will prosper if you do decide to feed them. </p>
<p>This is best given in the summer months when the plants are growing actively. I use tomato feed for just about all my houseplants in the summer. But the feed is very diluted for some plants, such as orchids, that can be sensitive to over-feeding. </p>
<p>Tomato feed for houseplants isn’t conventional but it works for me. Garden centres instead sell concentrated liquid feed specific for potted houseplants. </p>
<h2>5. When to repot?</h2>
<p>Many houseplants can withstand the same pot for a surprisingly long time, especially slow and steady growers like cacti. But if you keep foliage plants in warm conditions – particularly in homes with underfloor heating – they’re likely to need repotting regularly to avoid drying out. </p>
<p>When repotting, choose one or two pot sizes up. This allows for root space, but avoids an excess of stagnant compost.</p>
<figure class="align-center ">
<img alt="A person repotting a Philodendron Monstera." src="https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/524046/original/file-20230503-176-56rt5t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">When repotting your plants, choose one or two pot sizes up.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/repotting-home-plant-philodendron-monstera-deliciosa-2278696015">Simol1407/Shutterstock</a></span>
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</figure>
<p>It’s also important to use the right compost. Most plants do well in multipurpose compost – but not all. </p>
<p>Orchids prefer “orchid bark” that provides drainage and allows plenty of air around the roots. Carnivorous plants require specialist compost because they object to the high concentrations of nutrients formulated in multipurpose. And keep things green by avoiding peat – destroying peat bogs to make garden compost <a href="https://link.springer.com/article/10.1007/s10113-022-01900-8">is environmentally damaging</a>.</p>
<p>To allow your houseplants to flourish further, top-dress your pots with grit or shingle. This will keep <a href="https://www.rhs.org.uk/biodiversity/fungus-gnats">fungus gnats</a> (those pesky little black flies) at bay.</p>
<p>People often tell me they struggle to keep their houseplants alive. But keeping a thriving indoor thicket need not be difficult. Learning which plants to choose, how best to water and feed them, and how regularly they need repotting will all help to keep your indoor plants healthy.</p><img src="https://counter.theconversation.com/content/204291/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Thorogood does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>An expert’s tips on how to keep your indoor plants looking their best.Chris Thorogood, Head of Science and Public Engagement for Oxford Botanic Garden & Arboretum, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2028512023-04-06T06:53:19Z2023-04-06T06:53:19ZI’ve created a monstera! How to care for the ‘Swiss cheese plant’ in your life<figure><img src="https://images.theconversation.com/files/519436/original/file-20230404-22-rx2hys.jpg?ixlib=rb-1.1.0&rect=0%2C45%2C5853%2C3872&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>When I was growing up monsteras (sometimes known as monsteria) were not all that common, but neither were indoor plants. In fact, monsteras were out of fashion back then – but now monsteras are back and, appropriately, in a big way.</p>
<p>The plants that we know as monsteras, fruit salad plant or Swiss cheese plants (due to their holey leaves) are a rainforest plant called <em>Monstera deliciosa</em>. </p>
<p>They’re originally from Central America, around Mexico, but their iconic large leaves can now be found everywhere in popular culture – from fabric prints and earrings to tattoos and mugs.</p>
<p>So, what’s special about this large and lovely plant? And what’s the secret to keeping one happy and healthy?</p>
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<h2>Rainforest climbers</h2>
<p>In their natural habitat, monstera are climbers that can scramble through rainforest trees to <a href="https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b605#:%7E:text=Monstera%20deliciosa%2C%20commonly%20called%20split,is%20native%20to%20Central%20America">heights</a> of 25 metres or more. </p>
<p>Their large perforated leaves can be over a metre long, with regular nodes along the stem and roots often growing from these nodes. The roots help them hook onto other plants as they climb to access light. </p>
<p>There are about <a href="https://www.britannica.com/plant/Monstera">50 species</a> in the Monstera genus and some – such as <em>Monstera adansonii</em> (Adanson’s monstera or five holes plant) and <em>Monstera siltepecana</em> (silver monstera) – are popular indoor plants.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Monstera adansonii is a popular indoor plant.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<p>The name Monstera dates back to the <a href="https://www.aroid.org/genera/monstera/Madison_Monstera_Rec.pdf">1700s</a>, but these days most people associate this part of the name with its massive leaves. They are, after all, real monsters.</p>
<p>These huge leaves develop wherever there is a patch of light and allow the plant to grow quickly and shade out nearby competition. </p>
<p>The species name, deliciosa, refers to its fruit, which <a href="https://plants.ces.ncsu.edu/plants/monstera-deliciosa/">tastes</a> a little like a cross between banana and pineapple. </p>
<p>Monsteras are related to the arum lilies and produce white flowers on a fleshy stem (known as a “spadix”) that is surrounded by a cream or white leaf-like structure or bract (known as a “<a href="https://www.gardeningknowhow.com/garden-how-to/info/what-is-a-spathe.htm">spathe</a>”).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The fruit can be eaten.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Our first and only monstera began its life with us as a rather small indoor plant given as a gift in 1980. It remained indoors for a year or two, growing well, but then proved too great a temptation for a curious young son.</p>
<p>It was moved in its container (which was, by then, larger than its original pot) into a protected corner of an outside patio. </p>
<p>It had done well indoors, growing in a good quality potting medium, getting plenty of sunlight and regular water. Its leaves had gone from small philodendron-like features into the large and perforated foliage of the Swiss cheese plant.</p>
<p>The move outdoors did it no harm. Good light, regular water, fresh air and protection from winds and frosts saw it flourish into a plant with many large leaves and measuring nearly two metres in height. It filled a corner beautifully.</p>
<h2>A forgiving plant</h2>
<p>Monsteras are quite forgiving indoor plants. They are quite hardy (like many climbers) but as a tropical plant they like warm, humid conditions and moist, well-drained soils. </p>
<p>They also tolerate shade and so it’s not surprising they do well <a href="https://plants.ces.ncsu.edu/plants/monstera-deliciosa/">indoors</a>. </p>
<p>If you have a humus-rich potting medium and provide a climbing frame for them, they can thrive and survive for many years inside. However, you may need to give them a liquid fertiliser every year or two and re-pot them into a larger container.</p>
<p>While they are hardy and relatively easy to cultivate, Monsteras can decline if they become waterlogged.</p>
<p>This can easily happen if you over-water plants and have the container on a dish that gathers water.</p>
<p>Direct sunlight near a window can burn their leaves or lead to scorched patches. Leaves can also be damaged by warm dry air if plants are placed too close to heaters or heating ducts.</p>
<p>Their large leaves may also need dusting as the surfaces can become quite dirty, especially in bathrooms. The occasional prune will prevent the plant becoming too big indoors and removes yellow, burnt and older leaves.</p>
<p>Like many indoor plants, monsteras can benefit from a bit of R-and-R outdoors in a warm, sheltered spot for a few days.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Yellow leaves are a sign you’re likely doing something wrong.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<h2>Easily propagated</h2>
<p>As a fashionable plant, large monsteras can be quite pricey and variegated forms which grow more slowly are even more <a href="https://theconversation.com/multi-coloured-plants-are-suddenly-a-home-decor-must-have-heres-how-to-keep-them-alive-181163">expensive</a>.</p>
<p>However, <em>Monstera deliciosa</em> can be readily propagated from cuttings.</p>
<p>The easiest and quickest way of getting a new plant is to take a section of stem with a leaf or two attached and, if possible, with a few developing roots. Place it in a good quality potting mix in a large container.</p>
<p>You can also aerial layer monsteras, which is where you wrap potting mix or sphagnum moss around a node, preferably with some roots, in plastic or cling wrap. Make a couple of slash-like cuts in the stem and when roots develop, take your cutting from the stem.</p>
<p>They grow and establish quickly. So quickly, in fact, they’re considered a <a href="https://keyserver.lucidcentral.org/weeds/data/media/Html/monstera_deliciosa.htm">weed</a> along some New South Wales rivers.</p>
<p>After being on the patio for several years, the patio was to be demolished for an extension and our monstera either had to go or be planted in the garden. </p>
<p>We chose the latter and planted it in what we thought was an appropriate spot. </p>
<p>The monster responded as only a successful rainforest climber could. It spread, it climbed, it fruited and wherever there was a patch of light, it oriented a giant Swiss cheese leaf to gain maximum benefit for photosynthesis. </p>
<p>It is now over 40 years old, many metres long as it meanders its way through the garden and has been the source of several successful cuttings for family and friends.</p>
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<img src="https://counter.theconversation.com/content/202851/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The large, iconic leaves of monstera can now be found everywhere in popular culture – from fabric prints and earrings to tattoos and mugs. What makes monstera special and how do you keep one healthy?Gregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2009752023-03-14T12:24:27Z2023-03-14T12:24:27ZClimate change threatens spring wildflowers by speeding up the time when trees leaf out above them<figure><img src="https://images.theconversation.com/files/514776/original/file-20230311-17-7x9lo1.jpg?ixlib=rb-1.1.0&rect=23%2C0%2C3970%2C2952&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Native wildflowers, such as these Dutchman’s breeches (_Dicentra cucullaria_) that bloom early in spring are losing access to sunlight as trees leaf out earlier.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/26pTuFq">Katja Schulz/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>For <a href="https://nativeplantherald.prairienursery.com/2020/04/spring-ephemerals-in-the-woodland/">short-lived spring wildflowers</a> such as <a href="https://www.wildflower.org/plants/result.php?id_plant=anqu">wood anemone (<em>Anemone quinquefolia</em>)</a> and <a href="https://www.wildflower.org/plants/result.php?id_plant=dicu">Dutchman’s breeches (<em>Dicentra cucullaria</em>)</a>, timing is everything. These fleeting plants, known as ephemerals, grow in temperate forests around the world, leafing out and flowering early in spring before the trees towering above them leaf out. Emerge too early, and it will still be winter; emerge too late, and it will be too shady under the forest canopy for essential photosynthesis to happen. </p>
<p>Over their evolutionary history, these plants have figured out the best timing for their survival. But climate change is altering spring growing conditions, and plant life is changing along with it. </p>
<p>There are many examples of plants shifting flowering time in response to warming temperatures, such as <a href="http://dx.doi.org/10.1088/1748-9326/ac6bb4">cherry blossoms opening earlier and earlier</a> each year. However, when one part of an ecosystem shifts, will all the organisms that depend on it successfully shift too? Or will they be out of luck? And what if interconnected species respond to change at different rates, leading to disruptions in long-standing ecological relationships?</p>
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<figcaption><span class="caption">Participants in the federally funded USA National Phenology Network collect, store and share data on the timing of life cycle events in plants and animals and how climate change is altering those cycles.</span></figcaption>
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<p>Researchers have been asking these types of questions about phenology – the timing of biological events – <a href="https://press.uchicago.edu/ucp/books/book/chicago/W/bo8829988.html">related to climate change</a> for years. But most studies have focused on plant-animal interactions, like pollinators coming out at the <a href="https://doi.org/10.1042/ETLS20190139">wrong time for flowers</a>. Far fewer have analyzed plant-plant interactions, such as spring ephemerals that need time to grow before trees leaf out above them and block the sunlight.</p>
<p><a href="https://www.rprimacklab.com/">Our research group</a> has investigated the mismatch between understory wildflowers and canopy trees around Concord, Massachusetts, using historical observations recorded by Henry David Thoreau, the author of “<a href="https://www.gutenberg.org/files/205/205-h/205-h.htm">Walden,” his classic account of life in the woods</a>. We found that trees in Concord were more sensitive to spring temperatures than wildflowers were, and that this resulted in earlier tree leaf-out that <a href="https://doi.org/10.1111/ele.13224">reduced available light in the understory</a>. </p>
<p>This finding was an important first step, but we wanted to know whether these patterns persisted in other temperate forests in North America and across the Northern Hemisphere. Our 2023 study shows that <a href="https://doi.org/10.1111/1365-2745.14021">the answer is yes</a>.</p>
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<a href="https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A plant with small purple flowers on the forest floor." src="https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=509&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=509&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=509&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=640&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=640&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514778/original/file-20230311-16-lzomuu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=640&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Round-lobed hepatica (<em>Hepatica americana</em>) is an early-blooming wildflower with blue, white or pink flowers, most often found in shaded woodlands.</span>
<span class="attribution"><a class="source" href="https://plants.ces.ncsu.edu/plants/hepatica-americana/">Frtiz Flohr Reynolds/NC State Extension</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<h2>North American mismatches</h2>
<p>For this research we used specimens from herbariums – collections of plants that have been pressed, dried and cataloged. The plants we examined were collected across eastern North America over the past 100 years. We evaluated over 3,000 pressed plant specimens to chart leafing-out time for trees and flowering time for spring wildflowers. </p>
<p>The vast scale of this study was made possible because herbaria have digitized millions of photographs of plant specimens and <a href="https://naturalhistory.si.edu/research/botany/news-and-highlights/digitized">made them available online</a> over the past decade. Before this resource existed, researchers had to travel to many museums scattered around the country. </p>
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<figcaption><span class="caption">The herbarium at the Royal Botanic Gardens in Kew, England, is one of the world’s largest and supports genetic research on plants from around the globe.</span></figcaption>
</figure>
<p>Historical weather records are <a href="https://prism.oregonstate.edu">also available online now</a>. This allows researchers to determine spring temperatures for the year and place where each specimen was collected.</p>
<p>Our study enabled us to confirm the results of our work in Concord. We found that as temperatures warm, deciduous trees across eastern north America are advancing their leaf-out timing faster than native wildflowers are responding.</p>
<p>For example, during cooler springs with 24-hour average March and April temperatures of 41 degrees Fahrenheit (5 degrees Celsius), trees leafed out 13 days after native wildflowers. This gave the flowers almost two weeks of full sun on the forest floor. However, during warmer springs, with average temperatures of 58 F (15 C), trees leafed out only 10 days after native wildflowers. This gave the wildflowers about 25% less full sunlight time during which to photosynthesize. </p>
<p>As spring temperatures warm even further with climate change, we expect wildflowers will have even shorter periods of full sunlight. This can mean a sizable decrease in the flowers’ energy supply and ability to survive, grow and reproduce.</p>
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<a href="https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A pink three-lobed wildflower." src="https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514779/original/file-20230311-3323-eiamcv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Trilliums, like this <em>Trillium grandiflorum</em>, bloom from February through June across North America depending on their location.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Trillium_grandiflorum#/media/File:Trillium_grandiflorum_pink1.jpg">Eric Hill/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>We also observed that trees and wildflowers in the warmer southern part of their ranges advanced their leaf-out and flowering times faster, respectively, than those in colder northern locations. In these zones, we found greater timing differences between trees and wildflowers. This means the potential for phenological mismatch, where native wildflowers are more likely to be shaded out by trees, is greater in the southeast U.S. than in areas farther north.</p>
<h2>Parallels and differences on other continents</h2>
<p>For a 2022 study, we collaborated with colleagues from China and Germany to evaluate over 5,000 tree and wildflower specimens collected over the past 120 years. We wanted to see to whether the phenological mismatches that we documented in North America could also be found in temperate forests of <a href="https://doi.org/10.1038/s41467-022-34936-9">East Asia and central Europe</a>. </p>
<p>Our team found a common pattern across all three continents. Trees and wildflowers are active earlier now than in the past, and they are active earlier in warm years and places. </p>
<p>However, in a surprising twist, we didn’t see the North American pattern of trees being more sensitive than wildflowers on the other two continents. In Europe, wildflowers and canopy trees seemed to be shifting together over time. In Asia, the understory wildflowers were shifting more than the trees — meaning they might get more light, not less, in a warmer future.</p>
<p>The differences we found among the three regions were due primarily to variation in the sensitivities of the trees to temperature. Trees in eastern North America responded more strongly to temperature shifts, while Asian trees responded less strongly.</p>
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<p>These results suggest that eastern North American trees have become especially sensitive to temperature as a way of adapting to this region’s <a href="https://earthathome.org/hoe/ne/climate/#">highly variable climate</a>. In contrast, trees in East Asia are apparently more sensitive to other environmental cues, such as day length, when it comes to the timing of spring growth.</p>
<h2>Informing forest management</h2>
<p>Our results pose questions for further research. If spring temperatures aren’t the primary cues determining leaf-out and flowering times of trees and wildflowers in East Asia, what are those cues? How does the declining spring light window for wildflowers in eastern North America affect their energy budgets and ability to survive, grow and flower?</p>
<p>Another question is whether there are any practical management techniques, such as thinning overstory trees or removing invasive plants, that can help wildflowers deal with the ongoing challenges of climate change. Such strategies could help people appreciate and conserve the full range of plants in the forests we depend on and cherish around the world.</p><img src="https://counter.theconversation.com/content/200975/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard B. Primack receives funding from the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Benjamin R. Lee receives funding from the National Science Foundation and Morton Arboretum</span></em></p><p class="fine-print"><em><span>Tara K. Miller received funding from the National Science Foundation. </span></em></p>Many beloved wildflowers bloom in early spring, while trees are still bare and the flowers have access to sunlight. Climate change is throwing trees and wildflowers out of sync.Richard B. Primack, Professor of Biology, Boston UniversityBenjamin R. Lee, Postdoctoral Fellow in Biology, University of PittsburghTara K. Miller, Policy Research Specialist, Repair Lab, University of VirginiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1987242023-03-08T13:40:36Z2023-03-08T13:40:36ZOnce the Callery pear tree was landscapers’ favorite – now states are banning this invasive species and urging homeowners to cut it down<figure><img src="https://images.theconversation.com/files/513447/original/file-20230303-16-jjphd6.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C1933%2C1283&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bradford pear trees in bloom along a driveway in Sussex County, Del.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/9xfPoK">Lee Cannon/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>When people think of spring, they often picture flowers and trees blooming. And if you live in the U.S. Northeast, Midwest or South, you have probably seen a medium-sized tree with long branches, covered with small white blooms – the Callery pear (<em>Pyrus calleryana</em>). </p>
<p>For decades, Callery pear – which comes in many varieties, including “Bradford” pear, “Aristocrat” and “Cleveland Select” – was among the most popular trees in the U.S. for ornamental plantings. Today, however, it’s widely recognized as an <a href="https://www.govinfo.gov/content/pkg/FR-1999-02-08/pdf/99-3184.pdf">invasive species</a>. Land managers and plant ecologists <a href="https://scholar.google.com/citations?user=uRA-SZ0AAAAJ&hl=en&oi=sra">like me</a> are working to eradicate it to preserve biodiversity in natural habitats. </p>
<p>As of 2023, it is illegal to <a href="https://ohiodnr.gov/discover-and-learn/plants-trees/invasive-plants/callery-pear">sell, plant or grow Callery pear</a> in Ohio and <a href="https://www.agriculture.pa.gov/Plants_Land_Water/PlantIndustry/NIPPP/Pages/Callery-Pear.aspx">Pennsylvania</a>, and will become illegal in <a href="https://news.clemson.edu/invasive-bradford-pear-3-other-species-to-be-banned-for-sale-in-sc/">South Carolina</a> on October 1, 2024. <a href="https://news.ncsu.edu/2022/03/bounty-offered-on-bradford-pear-trees/">North Carolina</a> and <a href="https://www.lakeexpo.com/community/community_news/cut-down-your-bradford-pear-and-missouri-conservation-will-send-you-a-free-tree/article_df77978a-b51a-11ec-ab85-b39d20e73240.html">Missouri</a> will give residents free native trees if they cut down Callery pear trees on their property. </p>
<p>How did this tree, once in high demand, become designated by the U.S. Forest Service as “<a href="https://www.invasive.org/weedcd/pdfs/wow/callery_pear.pdf">Weed of the Week</a>”? The devil is in the biological details.</p>
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<figcaption><span class="caption">A Kentucky extension specialist explains why Callery pears initially seemed like a solution, but have proved to be a major problem.</span></figcaption>
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<h2>A quasi-perfect tree</h2>
<p>Botanists brought the Callery pear to the U.S. from Asia <a href="https://arboretum.harvard.edu/stories/the-rise-and-fall-of-the-ornamental-callery-pear-tree/">in the early 1900s</a>. They intentionally bred the horticultural variety to enhance its ornamental qualities. In doing so, they created an arboricultural wunderkind. As The New York Times <a href="https://www.nytimes.com/1964/01/05/archives/bradford-pear-has-many-assets-new-ornamental-fruit-offers-sturdy.html">observed in 1964</a>: </p>
<blockquote>
<p>“Few trees possess every desired attribute, but the Bradford ornamental pear comes unusually to close to the ideal.”</p>
</blockquote>
<p>Modern varieties of Callery pear produce an explosion of white flowers in springtime, followed by deep green summer foliage that turns deep red and maroon in autumn. They also are very tolerant of urban soils, which can be <a href="https://arboretum.harvard.edu/stories/urban-soil-problems-and-promise/">highly compacted</a> and hard for roots to penetrate. The trees grow quickly and have a rounded shape, which made them suitable for planting in rows along driveways and roadsides.</p>
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<a href="https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Tree with leaves mostly shaded red." src="https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/510742/original/file-20230216-22-hkyqya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A Callery pear turning red in fall.</span>
<span class="attribution"><span class="source">Ryan McEwan</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
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<p>During the post-World War II suburban development boom, Callery pear trees became extremely popular in residential settings. In 2005 the Society of Municipal Arborists named the “Chanticleer” variety the <a href="https://www.concreteconstruction.net/projects/infrastructure/arborists-select-urban-tree-of-the-year_o">urban street tree of the year</a>. But the breeding process that created this and other varieties of Callery pear was producing unexpected results.</p>
<h2>Cloning to produce an American original</h2>
<p>To ensure that each Callery pear tree had bright blooms, red foliage and other desired traits, horticulturists created identical clones through <a href="https://www.britannica.com/topic/graft">a process known as grafting</a>: creating seedlings from cuttings of trees with the desired characteristics. </p>
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<figcaption><span class="caption">Grafting is a method for propagating new fruit trees using buds from existing trees and fusing them onto a branch or stem of another tree, which is called the rootstock.</span></figcaption>
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<p>This approach eliminated the messy complexity of mixing genes during sexual reproduction and ensured that when each tree matured, it would have the characteristics that homeowners desire. Every tree of a specific variety was a genetically identical clone.</p>
<p>Grafting also meant Callery pear trees could not make fruits. Some fruit trees, such as peaches and tart cherries, can <a href="https://extension.umaine.edu/fruit/growing-fruit-trees-in-maine/pollination-requirements/">fertilize their flowers with their own pollen</a>. In contrast, Callery pear is self-incompatible: pollen on an individual tree cannot fertilize flowers on that tree. And since all Callery pears of a specific variety planted in a neighborhood would be identical clones, they would effectively be the same tree. </p>
<p>If a tree can’t produce fruits, it can’t disperse into natural habitats. Gardeners and landscapers thought it was perfectly safe to plant Callery pear near natural habitats, such as prairies, because the species was trapped in place by its reproductive biology. But the tree would break free from its isolation and spread seeds far and wide.</p>
<h2>The great escape</h2>
<p>University of Cincinnati botanist <a href="https://culleylab.com/home-page/members-lab/theresa-culley-pi/">Theresa Culley</a> and colleagues have found that as horticulturalists tinkered with Callery pears to produce new versions, they made the individuals different enough <a href="https://doi.org/10.1007/s10530-008-9386-z">to escape the fertilization barrier</a>. If a neighborhood had only “Bradford” pear trees, then no fruits could be produced – but once someone added an “Aristocrat” pear to their yard, then these two varieties could fertilize each other and produce fruits. </p>
<p>When Callery pear trees in gardens and parks started depositing seeds in nearby areas, wild populations of the trees became established. Those wild trees could pollinate one another, as well as neighborhood trees. </p>
<p>In today’s landscape, Callery pear is astonishingly fertile. The prolific flowering that horticulturists intentionally bred into these varieties now yields tremendous crops of pears each year. Although these little pears are generally not edible by humans, birds feed on the fruit, then fly away and excrete the seeds into natural habitats. Callery pear has become one of the <a href="https://www.fws.gov/program/invasive-species">most problematic invasive species</a> in the eastern United States. </p>
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<h2>A thorny problem</h2>
<p>Like other invasives, Callery pears crowd out native species. Once Callery pear seedlings <a href="https://doi.org/10.1007/s10530-022-02861-z">spread from habitat edges into grasslands</a>, they have advantages that allow them to dominate the site. </p>
<p>In <a href="https://mcewanlab.org/">my research lab</a>, we have found that Callery pear leafs out very early in spring and drops its leaves late in fall. This enables it to <a href="https://doi.org/10.3159/TORREY-D-22-00008.1">soak up more sun than native species</a>. We also have discovered that during invasion, these trees <a href="https://doi.org/10.1016/j.apsoil.2021.103989">alter the soil</a> and release chemicals that suppress the germination of native plants. </p>
<p>Callery pear is highly resistant to natural disturbances. In fact, when <a href="https://www.linkedin.com/in/meg-maloney-51b22b112/">my graduate student Meg Maloney</a> tried to kill the trees by using <a href="https://www.youtube.com/shorts/AeaEsDTnMLw">prescribed fires</a> or applying <a href="https://www.youtube.com/shorts/wtkMey4IItE">liquid nitrogen</a> directly to stumps after cutting the trees down, her efforts failed. Instead, the trees sprouted aggressively and <a href="https://muse.jhu.edu/article/883911#info_wrap">seemingly gained strength</a>.</p>
<p>Once Callery pear has escaped into natural areas, its seedlings produce <a href="https://doi.org/10.21273/HORTTECH04892-21">very sharp, stiff thorns</a> that can puncture shoes or even tires. This makes the trees a menace to people working in the area, as well as to native plants. Another nuisance factor is that when Callery pears bloom, they produce a <a href="https://www.npr.org/2015/04/24/401943000/whats-that-smell-the-beautiful-tree-thats-causing-quite-a-stink">strong odor</a> that many people find unpleasant.</p>
<p>Currently, <a href="https://www.invasive.org/alien/pubs/midatlantic/pyca.htm">directly applying herbicides</a> is the only known control for a Callery pear invasion. But the trees are so successful at spreading that poisoning their seedlings may simply create space for other Callery pear seedlings to establish. It is unclear how habitat managers can escape a confounding ecological cycle of invasion, herbicide application and re-invasion.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An open space studded with Callery pear trees, with dead grasses between the trees." src="https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513473/original/file-20230304-14-ct0blo.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A Callery pear invasion is crowding out native species on this agricultural land, converting it to woodland.</span>
<span class="attribution"><a class="source" href="https://extension.okstate.edu/fact-sheets/the-invasive-callery-pear.html">Oklahoma State University Extension</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Banned but not gone</h2>
<p>In response to work by the <a href="https://www.oipc.info/">Ohio Invasive Plants Council</a> and other experts, Ohio has taken the extraordinary step of <a href="https://codes.ohio.gov/ohio-administrative-code/rule-901:5-30-01">banning Callery pear</a> to thwart its ecological invasion into natural habitats. But the trees are common in residential areas across the state and have established vigorous populations in natural habitats. Ecologists will be working well into the future to maintain openness and biodiversity in areas where Callery pear is invading. </p>
<p>In the meantime, homeowners can help. Horticulturists recommend that people who have a Callery pear on their property should <a href="https://dyckarboretum.org/callery-pear-cut-them-down/">remove it and replace it</a> with something that is not an invasive species. Few trees possess every desired attribute, but many <a href="https://moinvasives.org/2018/03/29/plant-this-not-that-10-native-trees-to-plant-in-place-of-callery-pear/">native trees</a> have visually attractive features and will not threaten ecosystems in your region.</p>
<p><em>This article has been updated to reflect current state bans on Callery pear trees as of March 2024.</em></p><img src="https://counter.theconversation.com/content/198724/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ryan W. McEwan does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>They’re beautiful in bloom, but Callery pear trees crowd out native plants and turn productive open land into woody thickets.Ryan W. McEwan, Professor of Biology, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2001402023-02-23T06:15:26Z2023-02-23T06:15:26ZSome houseplants take in nutrients from roots outside the soil – and it may change how we care for them<p>In recent years, we have seen growing interest in houseplants, particularly <a href="https://www.theguardian.com/lifeandstyle/2022/jan/16/how-youthful-plant-lovers-are-shaking-up-staid-old-horticultural-ways">among younger generations</a>. Between 2019 and 2022, houseplant sales in the UK <a href="https://gca.org.uk/garden-centres-saw-green-shoots-of-recovery-in-2021/">increased by more than 50%</a>. Indoor plants are associated with a range of <a href="https://theconversation.com/houseplants-dont-just-look-nice-they-can-also-give-your-mental-health-a-boost-186982">environmental and health benefits</a> including cleaner air, better mental health and clearer thinking.</p>
<p>If you’re a plant parent, you probably know that plants need food and water to grow and survive. You will also know that plants have roots for taking these resources in and leaves to absorb the light energy required for photosynthesis. This sounds simple, but many of us (including me) struggle to keep our plants healthy.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
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</figure>
<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
<hr>
<p>Many common houseplants, especially those in the <a href="http://www.aroid.org/aroid/">aroid family</a> like the <a href="https://en.wikipedia.org/wiki/Monstera_deliciosa">monstera</a> (or the Swiss cheese plant) and <a href="https://en.wikipedia.org/wiki/Philodendron">philodendron</a> evolved in tough conditions. In their tropical or subtropical forest homes, these plants begin life on the ground but quickly climb the nearest tree to escape the dimly lit forest floor. They produce aerial roots that grow from stems above the ground and attach the plant to a tree’s trunk, allowing them to climb.</p>
<p>Knowing whether these roots take up nutrients or not will influence how we care for these plants. Currently, people tend to feed them in the soil with regular watering and plant food. So in a <a href="https://onlinelibrary.wiley.com/doi/10.1111/pce.14568">recent study</a>, my colleague and I compared aerial and soil-formed roots’ ability to take up nitrogen, an important plant food. </p>
<p>We expected the soil roots to better take up nitrogen because the soil is where the nutrients are – certainly in most houseplant potting mixes. Instead, we found that the aerial roots were far more efficient at taking up nitrogen than their soil counterparts.</p>
<h2>Reach for the sky</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A monstera plant growing up a neighbouring tree." src="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Monstera climb aerial roots to access lighter areas of the forest canopy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/monstera-plants-growing-heights-20-metres-788113741">Pomme Home/Shutterstock</a></span>
</figcaption>
</figure>
<p>As they climb, aroids grow more leaves. To sustain this growth, the plant will require more nutrients and water. Trees and shrubs effectively meet their demands for food and water by adding new pipes called xylem and phloem to the stem or roots. </p>
<p>The xylem is a tissue that transports water and nutrients upward, from the roots to the leaves. The phloem carries sugars the opposite way.</p>
<p>But monstera and philodendron (and other aroids) are instead related to grasses, meaning they are unable to make new pipes to take up resources. Without help, they would run out of suck – like trying to suck a thick milkshake through a small straw – leaving them unable to feed their increasing leaf area. </p>
<p>Monsteras and philodendrons overcome this problem by growing roots from the new stems as they grow (effectively adding more straws). These new roots grow downwards towards the soil where, in theory, they will take up nutrients and water. </p>
<p>But until now, this theory has not been tested.</p>
<h2>Caring for your plants</h2>
<p>We grew three common houseplants, a <a href="https://www.rhs.org.uk/plants/59193/philodendron-scandens/details">philodendron</a>, an <a href="https://www.gardenersworld.com/plants/anthurium-andreanum/">anthurium</a> (flamingo flower) and an <a href="https://www.rhs.org.uk/plants/32104/epipremnum-pinnatum-aureum/details">epipremnum</a> (devil’s ivy) both in humid conditions where there was plenty of water in the atmosphere, and in conditions typical of an office building (around 45% humidity).</p>
<p>After a few months, we recorded how big the plants were and then measured exactly how much nitrogen was taken up by each type of root. </p>
<p>Nitrogen uptake is measured by using a label – a bit like feeding flowers food dye. Nitrogen is present in nature in two “sizes”, called <a href="https://en.wikipedia.org/wiki/Isotopes_of_nitrogen">stable isotopes</a>. The heavy one, nitrogen-15, is far less abundant in nature than the lighter nitrogen-14, so when we fed the roots a solution high in the heavy nitrogen, we were able to measure how much of it was taken up compared to the other nitrogen isotope already in the roots. </p>
<p>To compare soil roots with aerial roots, we then fed the heavy nitrogen solution to individual roots and measured the amount of heavy nitrogen that was taken up by each. </p>
<p>Houseplants with more moisture in the air grew bigger and lost less water from their leaves during photosynthesis. In some situations, it was clear the plants were taking up water from their leaves.</p>
<p>Aerial roots were also much better at taking up nitrogen than soil roots. In anthurium and epipremnum, aerial roots took in up to 35% more nitrogen than the soil roots. </p>
<figure class="align-center ">
<img alt="A woman standing on a ladder tending to her houseplants." src="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Epipremnum’s aerial roots took in more nitrogen than the soil roots.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/focused-african-american-woman-tending-epipremnum-2244583755">DimaBerlin/Shutterstock</a></span>
</figcaption>
</figure>
<p>We are now exploring how and why this happens in more detail, but this could be because intense competition between neighbouring trees and shrubs in the plants’ original forest habitat strip soil of its nutrients. Being able to catch nutrients from decomposing leaf litter as they run down stems can thus be an advantage. The soil roots of some tropical trees even grow <a href="https://www.science.org/doi/10.1126/science.235.4792.1062">up the trunks</a> of neighbouring trees.</p>
<p>This suggests that we could be caring for these houseplants all wrong. We tend to ignore their aerial roots when all we need to do is give these roots a good spray with a liquid fertiliser. This will run down the aerial roots towards the stems and into the soil, making sure the soil roots are not neglected entirely.</p>
<p>Houseplants, particularly aroids, are a feature of many of our homes. But to fully experience their benefits, these indoor plants must be healthy. This may involve changing how we look after them.</p><img src="https://counter.theconversation.com/content/200140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Rasmussen does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research finds that some common houseplants take in nutrients from outside the soil.Amanda Rasmussen, Assistant Professor, Faculty of Science, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1896782022-08-31T02:48:18Z2022-08-31T02:48:18ZA new discovery shows major flowering plants are 150 million years older than previously thought<figure><img src="https://images.theconversation.com/files/481941/original/file-20220831-26-twbc84.jpeg?ixlib=rb-1.1.0&rect=210%2C121%2C953%2C594&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Prof Shuo Wang/Shi et al., 2022</span>, <span class="license">Author provided</span></span></figcaption></figure><p>A major group of flowering plants that are still around today, emerged 150 million years earlier than previously thought, according to a new study published today <a href="https://doi.org/10.1016/j.tplants.2022.08.004">in Trends in Plant Science</a>. This means flowering plants were around some 50 million years before the dinosaurs.</p>
<p>The plants in question are known as the buckthorn family or Rhamnaceae, a group of trees, shrubs and vines found worldwide. The finding comes from subjecting data on 100-million-year old flowers to powerful molecular clock techniques – as a result, we now know Rhamnaceae arose more than 250 million years ago.</p>
<h2>A widespread family</h2>
<p>Today, the buckthorn family of shrubs is widespread throughout Africa, Australia, North and South America, Asia and Europe. The <a href="https://www.agric.wa.gov.au/minor-fruits/jujubes-western-australia">important fruit jujube</a> or Chinese date belongs to the Rhamnaceae; other species are used in ornamental horticulture, as sources of medicine, timber and dyes, and to add nitrogen to the soil.</p>
<p>Flowering shoots of the shrub <em>Phylica</em>, now confined to South Africa, have <a href="https://www.nature.com/articles/s41477-021-01091-w">recently been found</a> in amber from Myanmar that is more than 100 million years old.</p>
<figure class="align-center ">
<img alt="Close-up of a leafy green plants with brownish plum-shaped fruit" src="https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481934/original/file-20220831-24-evxxoj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Jujube (Ziziphus jujuba) belongs to the buckthorn family.</span>
<span class="attribution"><span class="source">Alex___photo/Shutterstock</span></span>
</figcaption>
</figure>
<p>Together with Tianhua He, a molecular geneticist at Murdoch University, we combined skills to show these new fossils of <em>Phylica</em> could be used to trace the Rhamnaceae family (to which <em>Phylica</em> belongs) back to its origin almost 260 million years ago.</p>
<p>We did this by comparing the DNA of living plants of <em>Phylica</em> against the rate of DNA change over the past 120 million years, to set the molecular clock for the rest of the family.</p>
<figure class="align-center ">
<img alt="Close-up of a slightly fuzzy, spider-like flower head frozen in amber" src="https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481940/original/file-20220831-24-dygfw.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This Phylica flower was trapped in tree sap along with some charcoal over 100 million years ago. Time has turned it to amber.</span>
<span class="attribution"><span class="source">Prof Shuo Wang/Shi et al. 2022</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Older than we could have imagined</h2>
<p>It was previously believed that <em>Phylica</em> evolved about 20 million years ago and Rhamnaceae about 100 million years ago, so these new dates are much older than botanists could possibly have imagined. Since Rhamnaceae is not even considered an old member of the flowering plants, this means flowering plants arose more than 300 million years ago – some 50 million years before the rise of the dinosaurs.</p>
<figure class="align-center ">
<img alt="Close-up of a spiny plant with daisy-like flowers perched on each stem" src="https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481933/original/file-20220830-18-evxxoj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Phylica pubescens, also known as featherhead.</span>
<span class="attribution"><span class="source">Molly NZ/Shutterstock</span></span>
</figcaption>
</figure>
<p>But how did <em>Phylica</em> get from the Cape of South Africa to Myanmar? Our data on the history of the plant’s evolution show the most likely path is that <em>Phylica</em> migrated to Madagascar, then to the far north of India (most of which is under the Himalayas now), all of which were joined 120 million years ago.</p>
<p>India then separated and drifted north until it collided with Asia. The far northeast section, known as <a href="https://earth-planets-space.springeropen.com/articles/10.5047/eps.2011.10.011">the Burma tectonic plate</a>, became Myanmar about 60 million years ago. Sap, possibly released by fire-injured conifers, flowed over the <em>Phylica</em> flowers and preserved them intact as amber while India was still attached to Madagascar.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-plate-tectonics-mountains-and-deep-sea-sediments-have-maintained-earths-goldilocks-climate-183725">How plate tectonics, mountains and deep-sea sediments have maintained Earth's 'Goldilocks' climate</a>
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</em>
</p>
<hr>
<h2>Forged in fires</h2>
<p>In fact, the vegetation in which Rhamnaceae evolved was probably subjected to regular fires. The first clue was the charcoal <a href="https://www.nature.com/articles/s41477-021-01091-w">researchers have found</a> together with the <em>Phylica</em> fossils in the amber.</p>
<p>The second is that today, almost all living species in the <em>Phylica</em> subfamily have hard seeds that require fire to stimulate them to germinate. </p>
<p>I assessed the fire-related traits of as many living species as possible, then He traced them onto the evolutionary tree he had created, using a technique called ancestral trait assignment. This showed there was a strong possibility the earliest Rhamnaceae ancestor was fire-prone and produced hard seeds. </p>
<p>We have extensively studied the <a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2011.03663.x">evolutionary fire history of banksias</a>, which go back 65 million years, along with <a href="https://link.springer.com/article/10.1007/s10682-017-9905-4">proteas</a>, <a href="http://doi.org/10.1111/1365-2745.12513">pines</a>, <a href="https://doi.org/10.1111/brv.12483">wire rushes</a> and the kangaroo paw family.</p>
<p>Our new results make the buckthorn family of plants by far the oldest to show fire-related traits of all the plants we have studied over the past 12 years.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-is-testing-the-resilience-of-native-plants-to-fire-from-ash-forests-to-gymea-lilies-167367">Climate change is testing the resilience of native plants to fire, from ash forests to gymea lilies</a>
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<img src="https://counter.theconversation.com/content/189678/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Tianhua He was a co-author on the published study.</span></em></p>Millions of years before dinosaur footsteps first set tremors through the Earth, this flowering plant family was already thriving – and you can still find them in gardens today.Byron Lamont, Distinguished Professor Emeritus in Plant Ecology, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1874602022-07-26T04:40:05Z2022-07-26T04:40:05ZI spent a year squeezing leaves to measure their water content. Here’s what I learned<figure><img src="https://images.theconversation.com/files/475758/original/file-20220724-30560-l0ixqx.JPG?ixlib=rb-1.1.0&rect=0%2C0%2C4000%2C3000&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Tomás I. Fuenzalida</span>, <span class="license">Author provided</span></span></figcaption></figure><p>How do you tell if your plants need water? Recently, I asked this question of a group of about 40 biologists at the Australian National University. </p>
<p>Most of them said they would stick their fingers into the soil. If you want to be more scientific about it, most horticulturalists would argue it is best to weigh the pot to determine how much water it contains.</p>
<p>I took a different view. After building special tools to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/pce.14383">measure the “pulse” of plants</a>, I am more inclined to feel the leaves.</p>
<p>Not only can touch provide a new way to follow the flow of water through plant cells, it may also deliver new possibilities for plant monitoring and care. </p>
<h2>The rhythm of plants</h2>
<p>Plants have a natural rhythm, like a very slow heartbeat, caused by changing water pressure inside their cells. </p>
<p>Plants only beat around once a day, dehydrating during the day and rehydrating during the night. This process is too slow to watch for all but the most patient observers.</p>
<p>The pressure inside plant cells is called “turgor” and is usually between five and 20 atmospheres (up to 10 times the pressure inside a car tyre!). But while this pressure is large, plant cells are only a fraction of a millimetre in size. </p>
<p>For this reason, measuring turgor pressure has been traditionally been difficult and only done in lab settings. Put simply, we do not have a plug-and-play method to monitor the beating of plants.</p>
<h2>Squeezing leaves</h2>
<p>Measuring plant water status is pretty important. On a global scale, <a href="https://www.nature.com/articles/nature11983">more water flows through plants than through rivers</a>, and a great part of this flux is regulated by changes in leaf turgor pressure. </p>
<p>Similarly, <a href="https://unesdoc.unesco.org/ark:/48223/pf0000375737">agriculture uses about 70% of all the water managed by humans</a>, and <a href="https://www.annualreviews.org/doi/abs/10.1146/annurev-arplant-102820-012804">many forests around the world are succumbing to drought</a>. It is a key time to study the beating of plants. But where to start?</p>
<p>While doing my PhD studying water movement in plants, I was trying to find a simple way to measure turgor pressure and water content. </p>
<p>Although turgor is a property of single cells, I thought I could monitor a group of cells by carefully squeezing a leaf. </p>
<p>My ideas were simple. Leaves are thicker when they contain more water, so I could monitor the water content by measuring the thickness of the leaf, which I would do by squeezing it with a constant amount of force.</p>
<p>And to monitor the water pressure inside a leaf’s cells, I could measure the force exerted by the leaf when constrained to a given thickness.</p>
<p>As it turned out, these two ideas were not new – only new to me, and perhaps new to plant science. Materials scientists use tests like these all the time: a constant-force test is called a creep experiment, while a constant-thickness test is called a stress relaxation experiment. </p>
<h2>How it works</h2>
<p>A year of tinkering and thinking about this problem allowed me to test my ideas in a very simple way. I bought a micrometer (a workshop tool used to measure distances very accurately), coupled it with a motor, a force sensor and some computer controls, and devoted myself to squeezing leaves. </p>
<p>Preliminary tests worked well, and then I couldn’t stop doing it! </p>
<p>Within the next six months, I had replaced the last chapter of my PhD with this serendipitous project. Colleagues and I successfully validated and <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/pce.14383">published</a> this simple method to monitor plant water status. </p>
<p>In the figure below, you can see the changes in the leaf thickness and turgidity of a grey mangrove (<em>Aviennia marina</em>) measured under changing light conditions.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475748/original/file-20220724-30685-h5ea7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Monitoring the beating of plants is possible using a simple device that squeezes leaves with a constant force (green) or with a constant thickness (blue). The resulting thickness and pressure are related to water content and turgor pressure.</span>
</figcaption>
</figure>
<h2>Touching plants</h2>
<p>Measuring the beating of plants is important, but this is not the only exciting aspect of this project. </p>
<p>More broadly, touch-based measurements could uncover a new wealth of information about plant life. This venture may help us understand climate, save water, and hopefully help us in addressing “<a href="https://theconversation.com/botanists-are-disappearing-just-when-the-world-needs-them-most-186849">plant blindness</a>”. </p>
<p>Plants are very adaptable organisms. Much of their adaptability comes from the ability to modify their body plan to suit different conditions. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/botanists-are-disappearing-just-when-the-world-needs-them-most-186849">Botanists are disappearing – just when the world needs them most</a>
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<hr>
<p>Being modular organisms made up of a collection of different cells, plants often modify the structure of cells and tissues, the strength of their walls, and the concentration of water-retaining compounds inside the cells. All of these properties, like turgor, are difficult to measure.</p>
<p>Touch provides scientists with a simple tool to study these mechanical properties of plant tissues.</p>
<p>A simple robotic system that could stay on a tree and continuously “feel” how the properties of its leaves (and stems, fruits and roots) change over time would have vast applications in research and industry.</p><img src="https://counter.theconversation.com/content/187460/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tomás I. Fuenzalida does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Carefully squeezing plant leaves can reveal how much water they contain – and touch could reveal many other hard-to-measure properties of plants.Tomás I. Fuenzalida, Postdoctoral Fellow, Research School of Biology, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1868492022-07-13T17:03:03Z2022-07-13T17:03:03ZBotanists are disappearing – just when the world needs them most<figure><img src="https://images.theconversation.com/files/473904/original/file-20220713-2711-s6f3ot.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4368%2C2909&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Annika Geijer-Simpson</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Can you recall any of the plants you saw today? </p>
<p>Probably not. As a species, we are not programmed to recognise and register everything we see within our field of vision. This would be an overwhelming amount of information for our brains to process. </p>
<p>You can however, with a little time and practise, be trained to read the plants around you: to recognise which species they belong to and their names, their relationships with other organisms and what they are telling you about the environment they live in. This is to develop what some call a natural literacy.</p>
<p>Most people suffer from what is commonly known as “<a href="https://theconversation.com/plant-blindness-is-obscuring-the-extinction-crisis-for-non-animal-species-118208">plant blindness</a>”, a term coined by US botanists Elisabeth Schussler and James Wandersee. They described it as “the inability to see or notice the plants in one’s own environment”. Unless taught, people don’t tend to see plants – despite the fact that at any given moment, there is likely to be a plant – or something made by plants – nearby. </p>
<p>In our <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.9019">latest study</a>, my fellow researchers and I found that people are not only less aware of plants through a lack of exposure and a loss of knowledge, but demand for an education in botany and opportunities to study it in the UK have diminished too. </p>
<h2>The extinction of botanical education</h2>
<p>Botany, once a compulsory component of many biology degrees and school programmes, is disappearing fast. It has been over a decade since a student was enrolled in a botany degree in the UK. We believe there has been a gradual erosion of knowledge about plants among biology graduates and the general public as a result.</p>
<figure class="align-center ">
<img alt="Students in gowns stand in rows for a university graduation ceremony." src="https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473891/original/file-20220713-20-5vnaux.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Botany graduates are now few and far between.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/university-students-attending-graduation-ceremony-uk-1103646821">Juraj Micka/Shutterstock</a></span>
</figcaption>
</figure>
<p>We examined the number of UK students graduating across a variety of biological science programmes from 2007 to 2019 and found that students studying plant science were outnumbered almost one to 200 by those studying general biology. When we scrutinised the modules offered to students on plant science courses at UK universities, we were surprised to find that only 14% focused solely on plants. Only 1% of modules in plant science and biological science programmes offered any form of training in identifying plant species.</p>
<p>Students are not introduced to the diversity of plant forms and functions at UK universities and are certainly not engaged with how fascinating and dynamic the floral world is. The result is a growing skills gap, with a looming shortage of professionals capable of effectively managing environmental projects. Well-meaning but careless management is not just ineffective, it can add to environmental degradation. </p>
<p>For example, planting thirsty species of tree in the name of capturing carbon from the air can deprive <a href="https://theconversation.com/peat-bogs-restoring-them-could-slow-climate-change-and-revive-a-forgotten-world-139182">precious bog plants</a> of much needed water. Recklessly cutting and strimming grasslands can wipe out populations of rare orchids.</p>
<p>Harnessed properly, there is no doubt that plants and the services they provide can help solve looming climate and ecological crises. Restoring flood meadows and riverside habitats can reduce flooding from the extreme downpours which are likely to become more common in some areas as the Earth warms.</p>
<p>Less teaching about plants and the ensuing disconnection from the natural world will, if not reversed, have irreparable and disastrous consequences. How many generations of botanists remain before we no longer have the expertise to understand when ecosystems are on the brink of irreparable loss and damage?</p>
<p>The <a href="https://www.nature.scot/doc/nature-based-jobs-and-skills-action-plan-2021-2022">Scottish government</a> has highlighted the lack of a skilled workforce to implement nature-based solutions and argues that “nature literacy” must become a core skill for various professionals, from planners, engineers, architects and educators to farmers, foresters and fishers.</p>
<p>The problem is vast. Various other studies have documented falling plant literacy <a href="https://www.pnas.org/doi/10.1073/pnas.2103683118">worldwide</a>. While other studies have identified that plant content is often neglected in <a href="https://www.tandfonline.com/doi/abs/10.1080/00219266.2021.1920301?journalCode=rjbe20">textbooks</a> and students who are unable to recognise even <a href="https://www.mdpi.com/2227-7102/9/2/85">local plant species</a>. Our study revealed that the UK curriculum neglects plant ecology and how to identify species, with most of this education taking place at a rudimentary level in primary schools.</p>
<figure class="align-center ">
<img alt="A student compares a plant's leaves with images in a textbook." src="https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473894/original/file-20220713-9696-79saak.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The UK education system is failing to equip students with the knowledge to identify plant species.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/identifying-leaves-research-japan-1505111552">Cassandra Lord/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Reversing the decline in plant knowledge</h2>
<p>Reviving botanical education is possible by presenting students and the public with evidence of how plants can combat the challenges of the 21st century. An invested and knowledgeable public is one well-equipped to demand environmental policy reform. </p>
<p>Botanists can support this ambition, but ultimately, change needs to come from those who decide policy. This is why botanists must agitate to bring botany back into the classroom and beyond. </p>
<p>One thing we couldn’t fully convey in our paper is just how fascinating and exciting the plant kingdom is. In my experience as an educator, there is no student who cannot be reached. Stories about plants are woven into every society’s history, politics and culture. Plants are relevant to every person on the planet – most just don’t know it yet.</p><img src="https://counter.theconversation.com/content/186849/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sebastian Stroud receives funding from Natural Environment Research Council (NERC). </span></em></p>Botany is disappearing from university modules in the UK.Sebastian Stroud, PhD Candidate in Ecology and Botany, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1827972022-05-12T16:54:18Z2022-05-12T16:54:18ZHow to grow plants on the moon – new study<figure><img src="https://images.theconversation.com/files/462733/original/file-20220512-15-48cxeg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Harvest Moon - October 1 2020.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/kevinmgill/50408130448/in/photolist-2jNoQZo-MaNn86-YmFAiM-8DhMXA-6u8twP-MiwJw6-z9ayob-A79AV8-A7a2FR-zNGdFR-A3TUKE-z9b2gj-A3VzG5-A3TQEA-zNB78E-A52YwG-A3Vw5f-A41GKo-z9qN58-GtP6Kk-z9jMzx-A3UHC7-Z6ScTj-A7a7Et-A54ucw-zNCAx3-8Dk1qN-z9k9ak-A3VrH9-z9bKDW-2hv5QFR-A3V535-z9bskY-A54KyU-A6du3n-A7aJMD-A3Vy6E-A5a789-z9bB3N-A6cZBe-A3UECQ-z9bDW3-A6iYY8-z9bVa9-z9c1KC-zNNdwv-z9kscH-2mPoWzs-fZsXjr-zNCsLS">Kevin Gill/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>What do you need to make your garden grow? As well as plenty of sunshine alternating with gentle showers of rain – and busy bees and butterflies to pollinate the plants – you need good, rich soil to provide essential minerals. But imagine you had no rich soil, or showers of rain, or bees and butterflies. And the sunshine was either too harsh and direct or absent – causing freezing temperatures. </p>
<p>Could plants grow in such an environment – and, if so, which ones? This is the question that colonists on the Moon (and Mars) would have to tackle if (or when) human exploration of our planetary neighbours goes ahead. Now a new study, <a href="https://www.nature.com/articles/s42003-022-03334-8">published in Communications Biology</a>, has started to provide answers. </p>
<figure class="align-right ">
<img alt="Image of Arabidopsis thaliana." src="https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=832&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=832&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=832&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1045&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1045&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462778/original/file-20220512-19-qtqlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1045&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Arabidopsis thaliana on Earth.</span>
<span class="attribution"><span class="source">wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The researchers behind the study cultivated the fast-growing plant <a href="https://elifesciences.org/articles/06100"><em>Arabidopsis thaliana</em></a> in samples of lunar regolith (soil) brought back from three different places on the Moon by the Apollo astronauts. </p>
<h2>Dry and barren soil</h2>
<p>This is not the first time that <a href="https://www.sciencedirect.com/science/article/abs/pii/0273117794903336?via%3Dihub">attempts have been made</a> to grow plants in lunar regolith though, but it is the first to demonstrate why they don’t thrive.</p>
<p>The lunar regolith is very different from terrestrial soils. For a start, it doesn’t contain organic matter (worms, bacteria, decaying plant matter) that is characteristic of soil on Earth. Neither does it have an inherent water content. </p>
<p>But it is composed of the same minerals as terrestrial soils, so assuming that the lack of water, sunlight and air is ameliorated by cultivating plants inside a lunar habitat, then the regolith could have the potential to grow plants.</p>
<p>The research showed that this is indeed the case. Seeds of <em>A. thaliana</em> germinated at the same rate in Apollo material as they did in the terrestrial soil. But while the plants in the terrestrial soil went on to develop root stocks and put out leaves, the Apollo seedlings were stunted and had poor root growth. </p>
<p>The main thrust of the research was to examine plants at the genetic level. This allowed the scientists to recognise which specific environmental factors evoked the strongest genetic responses to stress. They found that most of the stress reaction in all the Apollo seedlings came from salts, metal and oxygen that is highly reactive (the last two of which are not common in terrestrial soil) in the lunar samples. </p>
<figure class="align-center ">
<img alt="Image of the plants grown in the experiment." src="https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=269&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=269&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=269&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=339&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=339&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462779/original/file-20220512-12-vzo0jy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=339&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Experimental results, with different wells for each soil.</span>
<span class="attribution"><span class="source">Paul et al.</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The three Apollo samples were affected to different extents, with the Apollo 11 samples being the slowest to grow. Given that the chemical and mineralogical composition of the three Apollo soils were fairly similar to each other, and to the terrestrial sample, the researchers suspected that nutrients weren’t the only force at play. </p>
<p>The terrestrial soil, called JSC-1A, was not a regular soil. It was a mixture of minerals prepared specifically to simulate the lunar surface, and contained no organic matter. </p>
<p>The starting material was basalt, just as in lunar regolith. The terrestrial version also contained natural volcanic glass as an analogue for the “<a href="https://www.lehigh.edu/%7Einmndust/ani1c.html">glassy agglutinates</a>” – small mineral fragments mixed with melted glass – that are abundant in lunar regolith. </p>
<p>The scientists recognised the agglutinates as one of the potential reasons for lack of growth by the seedlings in the Apollo soil compared to the terrestrial soil, and also for the difference in growth patterns between the three lunar samples. </p>
<p>Agglutinates are a common feature of the lunar surface. Ironically, they are formed by a process referred to as “lunar gardening”. This is the way that the regolith changes, through bombardment of the Moon’s surface by cosmic radiation, solar wind and minuscule meteorites, also known as space weathering. </p>
<p>Because there is no atmosphere to slow down the tiny meteorites hitting the surface, they impact at high velocity, causing melting and then quenching (rapid cooling) at the impact site. </p>
<p>Gradually, small aggregates of minerals build up, held together by glass. They also contain tiny particles of iron metal (nanophase iron) formed by the space weathering process. </p>
<p>It is this iron that is the biggest difference between the glassy agglutinates in the Apollo samples and the natural volcanic glass in the terrestrial sample. This was also the most probable cause of the metal-associated stress recognised in the plant’s genetic profiles.</p>
<p>So the presence of agglutinates in the lunar substrates caused the Apollo seedlings to struggle compared with the seedlings grown in JSC-1A, particularly the Apollo-11 ones. The abundance of agglutinates in a lunar regolith sample depends on the length of time that the material has been exposed on the surface, which is referred to as the “<a href="https://articles.adsabs.harvard.edu//full/1978LPSC....9.2287M/0002287.000.html">maturity</a>” of a lunar soil.</p>
<p>Very mature soils have been on the surface for a long time. They are found in places where regolith has not been disturbed by more recent impact events that created craters, whereas immature soils (from below the surface) occur around fresh craters and on steep crater slopes. </p>
<p>The three Apollo samples had different maturities, with the Apollo 11 material being the most mature. It contained the most nanophase iron and exhibited the highest metal-associated stress markers in its genetic profile.</p>
<h2>The importance of young soil</h2>
<p>The study concludes that the more mature regolith was a less effective substrate for growing seedlings than the less mature soil. This is an important conclusion, because it demonstrates that plants could be grown in lunar habitats using the regolith as a resource. But that the location of the habitat should be guided by the maturity of the soil.</p>
<p>And a last thought: it struck me that the findings could also apply to some of the impoverished regions of our world. I don’t want to rehearse the old argument of “Why spend all this money on space research when it could be better spent on schools and hospitals?”. That would be the subject of a different article. </p>
<p>But are there technology developments that arise from this research that could be applicable on Earth? Could what has been learned about stress-related genetic changes be used to develop more drought-resistant crops? Or plants that could tolerate higher levels of metals?</p>
<p>It would be a great achievement if making plants grow on the Moon was instrumental in helping gardens to grow greener on Earth.</p><img src="https://counter.theconversation.com/content/182797/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monica Grady is Professor of Planetary and Space Sciences at the Open University. She receives funding from the STFC and the UK Space Agency. She is Chancellor of Liverpool Hope University and a Senior Research Fellow at the Natural History Museum. Follow her on twitter @MonicaGrady</span></em></p>Take note, future colonisers: you may be able to grow stuff in certain places on the Moon.Monica Grady, Professor of Planetary and Space Sciences, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1798122022-04-13T12:13:16Z2022-04-13T12:13:16ZRedwood trees have two types of leaves, scientists find – a trait that could help them survive in a changing climate<figure><img src="https://images.theconversation.com/files/457498/original/file-20220411-11-h2ic9b.jpg?ixlib=rb-1.1.0&rect=16%2C0%2C5542%2C3709&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coastal redwoods in Felton, California.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/coastal-redwoods-stand-in-the-henry-cowell-redwoods-state-news-photo/915647562">Carolyn Van Houten/The Washington Post via Getty Images</a></span></figcaption></figure><p>Coast redwoods are amazing trees that scientists have studied for generations. We know they are <a href="https://doi.org/10.1038/nature02417">the tallest living trees</a> and have survived for millennia, <a href="https://academic.oup.com/jof/article-abstract/29/6/939/4719848">resisting fire</a> and <a href="https://nzjforestryscience.springeropen.com/articles/10.1186/s40490-014-0017-4">pests</a>. Because redwoods are long-lived, large and decay-resistant, the forests they dominate store <a href="https://doi.org/10.1016/j.foreco.2016.05.018">more above-ground mass, and thus presumably more carbon</a>, than any other ecosystem on Earth. </p>
<p>Nonetheless, while working on a recently published study, colleagues at the <a href="https://scholar.google.com/citations?user=qeqqJqwAAAAJ">University of California</a>, <a href="https://scholar.google.com/citations?user=S3LivCgAAAAJ&hl=es">Davis</a>, and <a href="https://scholar.google.com/citations?user=5dqacuQAAAAJ&hl=en">Cal Poly</a> <a href="https://kerhoulasforestlab.weebly.com/">Humboldt</a> and <a href="https://scholar.google.com/citations?hl=en&user=Qv4DpXAAAAAJ">I</a> learned a secret that had been sitting right under our noses. </p>
<p>Redwoods, it turns out, have two types of leaves that look different and perform very different tasks. This previously unknown feature helps the trees adapt to both wet and dry conditions – an ability that could be key to their survival in a changing climate.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-swLTsWXPII?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Redwoods can live for more than 2,000 years and grow to more than 350 feet tall.</span></figcaption>
</figure>
<h2>Just enough water</h2>
<p>Wherever trees grow, sooner or later their leaves get wet. For trees in wet environments, this can be a problem if films of water <a href="https://doi.org/10.1111/j.1365-3040.1995.tb00377.x">cover their stomata</a>. These tiny pores allow carbon dioxide to enter leaves so the tree can combine it with water to make plant tissue through <a href="https://www.usda.gov/media/blog/2015/03/17/power-one-tree-very-air-we-breathe">photosynthesis</a>. Many trees that are common to wet forests have leaves with adaptations that <a href="https://doi.org/10.1073/pnas.95.24.14256">prevent these water films from forming</a>. </p>
<p>In contrast, trees growing in dry environments take advantage of brief bouts of leaf wetness to <a href="https://doi.org/10.1111/nph.15307">take up valuable water</a> directly across the surfaces of their leaves, <a href="http://dx.doi.org/10.1111/pce.13439">through special leaf structures</a>, and even <a href="https://doi.org/10.1111/pce.14041">through their stomata</a>. But some trees, including coast redwoods, live in both wet and dry environments with intense seasonal variation. </p>
<p>For broad-leaved trees like the <a href="https://doi.org/10.1104/pp.114.242040">holm oak</a>, which grows in Mediterranean climates with dry summers and rainy winters, this seasonal wetness challenge is relatively easy to overcome. Their stomata are on the sheltered undersides of their leaves, which keeps them clear of water, while the leaves’ top surfaces absorb water. But redwoods are conifers, or cone-bearing trees, with <a href="https://ucanr.edu/sites/forestry/California_forests/http___ucanrorg_sites_forestry_California_forests_Tree_Identification_/Coast_Redwood_Sequoia_sempervirens_198/">thin, flat needlelike</a> leaves, and they need a different way to balance the competing goals of repelling and absorbing water. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Oval-shaped opening on a wavy green surface." src="https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=615&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=615&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=615&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=772&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=772&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457504/original/file-20220411-11-gw6ixl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=772&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A single stoma on a tomato leaf, shown via electron microscope.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Stoma#/media/File:Tomato_leaf_stomate_1-color.jpg">Photohound/Wikipedia</a></span>
</figcaption>
</figure>
<p>We knew we wanted to explore how redwoods met the paradoxical challenge of leaf wetness, how much water redwoods could absorb and which leaf features caused differences in water uptake capacity. What we learned came as a total surprise.</p>
<h2>Big trees with big secrets</h2>
<p>Scientists have long known about redwoods’ <a href="https://doi.org/10.1111/j.1365-3040.2004.01207.x">ability to absorb water through their leaves</a>. But figuring out how much water redwoods can absorb this way, and how the capacity to do so might vary from one type of climate to another, is a real challenge in this species. </p>
<p>First, a big redwood has over 100 million leaves with a <a href="https://doi.org/10.1016/j.foreco.2016.05.018">massive amount of surface area</a> for water absorption. And these leaves <a href="https://doi.org/10.1016/j.foreco.2016.05.018">drastically change structure with height</a>, going from long and flat to short and awllike. So we couldn’t get this right by simply picking leaves at ground level.</p>
<p>To complicate matters further, gravity is always pushing down on the giant column of water rising upward through a redwood’s trunk. As a result, leaves at the top of the tree <a href="https://doi.org/10.1038/nature02417">always have less available water</a> than those lower down. The treetop’s inherent dryness should pull water into the leaf more quickly than into water-rich leaves at the bottom, just as a dry sponge picks up water faster than a damp one. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing historic and current distribution of coast redwoods." src="https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=716&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=716&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=716&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=899&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=899&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457508/original/file-20220411-26-5iu2ea.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=899&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Coast redwoods’ range extends from southern Oregon to California’s Big Sur coast.</span>
<span class="attribution"><a class="source" href="https://www.parks.ca.gov/?page_id=24723">California Department of Parks and Recreation</a></span>
</figcaption>
</figure>
<p>For an accurate picture of how redwoods absorbed water, we needed leaves from trees in wet and dry environments, and from multiple heights on those trees. To get them to their natural gravity-based water levels for analysis, we put our leaf samples in a <a href="https://doi.org/10.1111/pce.13327">fog chamber</a> – in this case, an ice chest hooked up to a room humidifier – and measured weight gain over time to see how much water they could absorb.</p>
<h2>A trail of clues</h2>
<p>As we took apart clusters of redwood shoots to immerse them in fog, we divided each cluster into pieces. Redwood shoot clusters fan out from a woody core and are segmented into individual shoots of multiple ages, each with its own set of leaves. We separated shoots along <a href="https://doi.org/10.1093/treephys/tpu011">the woody central axis</a> from the much more common pliable shoots on the outer edges of each cluster. </p>
<p>It quickly became obvious that shoots from the center axis had leaves that could absorb water three times faster than peripheral leaves. When we looked inside the leaves with a microscope, we understood that they were two completely different types. They don’t look the same on the outside either, but this was so unexpected that we needed to see their internal structure to really convince ourselves. </p>
<p>The axial leaves were packed with water storage cells, but their phloem – tubes in the leaves that export photosynthetic sugars to the tree – appeared to be blocked and useless. If a tree has leaves, the conventional wisdom is that they are there for photosynthesis, but we wondered whether the axial leaves had a different purpose.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two types of redwood shoots" src="https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457500/original/file-20220411-13-ve7ex9.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Redwoods’ broad peripheral leaves, shown at left, make up about 95% of the trees’ leaf area and do all the photosynthesis. Their axial leaves, at right, are adept at absorbing water.</span>
<span class="attribution"><span class="source">Alana Chin</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>With some additional measurements, we found that redwoods’ axial leaves are specialized for absorbing water. Differences between the surfaces of axial and peripheral leaves, especially their wax coverage, cause the differences in their water absorption rates.</p>
<p>Unlike the axial leaves, redwoods’ peripheral leaves have waxy surfaces with lots of stomata. This helped to explain how they <a href="https://academic.oup.com/treephys/article/30/10/1260/1658568">photosynthesize year-round</a> regardless of the long wet season in much of their current habitat.</p>
<p>Further analysis showed that the redwoods’ axial leaves account for only about 5% of the trees’ total leaf area, and barely produce enough energy through photosynthesis to maintain themselves. But they contribute up to 30% of the trees’ total water absorption capacity. Together these two types of leaves balance the dueling requirements of photosynthesis and water absorption, allowing redwoods to thrive in both wet and dry habitats. </p>
<p>[<em>More than 150,000 readers get one of The Conversation’s informative newsletters.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-150K">Join the list today</a>.]</p>
<p>Using large-scale <a href="https://www.youtube.com/watch?v=B4JAyIAhgIU&t=89s">tree measurements</a> and <a href="https://doi.org/10.1890/14-1016.1">equations for estimating redwood leaf area</a>, we estimated that these thirsty giants can absorb as much as 105 pounds (48 kilograms) of water in the first hour of a rainfall wetting their leaves. That’s equivalent to 101 pints of beer.</p>
<h2>The significance to redwoods</h2>
<p>Understanding what causes the variation in redwood leaves’ uptake capacity can help us gauge differences in water uptake capabilities among trees and environments, now and in the future. In my opinion, this is the most potentially useful part of our study.</p>
<p>Redwoods vary their two leaf types to suit their local climates. In wet rainforests in the northern part of their range, above Mendocino County, the trees invest in fewer of the axial leaves that are specialized for absorbing water. These leaves are concentrated in the trees’ lower crowns, leaving the photosynthetically <a href="https://doi.org/10.1093/treephys/tpp037">high-performing treetops</a> free to maximize sugar production in the bright sun. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Leaf under a microscope, covered with white dots." src="https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=510&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=510&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=510&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=641&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=641&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457510/original/file-20220411-6515-ece0z9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=641&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wax on the surface of a redwood leaf. The white dots are water-resistant plugs in the stomata.</span>
<span class="attribution"><span class="source">Marty Reed</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In dry forests on the southern margins of redwoods’ range, trees have more axial leaves in their water-stressed tops. This allows them to take better advantage of briefer leaf-wetting events, but it means they photosynthesize less per leaf area than redwoods in wetter areas. </p>
<p>Redwoods’ ability to shift leaf types to match regional climatic differences may help them adjust to climate change in an <a href="https://theconversation.com/californias-water-supplies-are-in-trouble-as-climate-change-worsens-natural-dry-spells-especially-in-the-sierra-nevada-173142">ever-drier California</a>. That would be good news for conserving these epic trees, and it may be a promising feature to investigate as scientists try to <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.15592">link drought tolerance traits</a> to regional differences among redwood populations.</p><img src="https://counter.theconversation.com/content/179812/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alana Chin received funding from the NSF GRFP</span></em></p>New research shows that coast redwood trees have a surprising adaptation that helps them thrive in both wet and dry environments.Alana Chin, Postdoctoral Fellow in Plant Ecology, Swiss Federal Institute of Technology ZurichLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1693372022-01-17T13:16:08Z2022-01-17T13:16:08ZWhy do plants grow straight?<figure><img src="https://images.theconversation.com/files/438139/original/file-20211216-19-1l3wauj.jpg?ixlib=rb-1.1.0&rect=12%2C0%2C2032%2C1523&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">_Allium schoenoprasum_, better known as chives.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/Tvikbd">Andreas Rockstein/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
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<blockquote>
<p>Why do plants grow straight? – Sara H., age 5, New Paltz, New York</p>
</blockquote>
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<p>Have you ever been at a sporting event or concert and had to wiggle and reposition to get in just the right spot to see the action? Maybe you needed to shift left or right to see between two people. Perhaps you even had to squat on your seat to see over the person in front of you.</p>
<p>Well, plants often have to do something similar so that they can “see” as much light as possible. Plants need light to perform photosynthesis – making sugars from water and carbon dioxide in the air to feed themselves.</p>
<p>If sunlight is directly above them, then plants will grow straight up toward it. </p>
<p>Sometimes, though, it’s not that simple. For example, you might have seen house plants bending towards a window rather than growing straight and tall. When light comes from an angle, plants will curve toward it to get better access to the light they need to grow. Hormones in the plant’s tissues, called <a href="https://www.britannica.com/science/auxin">auxins</a>, make cells on the dark side of the plant grow taller, bending the plant toward the light. </p>
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<figcaption><span class="caption">Plants contain hormones called auxins that make them grow in the direction of light sources.</span></figcaption>
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<p>In a forest, plants may branch out so that their leaves are in open patches of sun, rather than in the shade. This often happens if taller bushes and trees tower over them, or if they are growing in a crowd of other plants. It’s much like humans seeking out sunny spots or reaching their hands toward a campfire to warm up when they feel cold outdoors.</p>
<p>[<em>More than 140,000 readers get one of The Conversation’s informative newsletters.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140K">Join the list today</a>.]</p>
<p>Humans twist or bend by changing our body positions temporarily, but when plants twist, bend or elongate, they are actually growing toward the light. The types of plants that reposition themselves to see the light are species that grow in a slow but determined way.</p>
<p>Other types of plants may not grow straight because they have different strategies. For example, strawberries grow close to the ground and spread sideways by sending out <a href="https://kids.britannica.com/kids/article/strawberry/433049">runners</a> – stems that spread out just above the ground to create new plants. </p>
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<a href="https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Stone house with ivy reaching up one wall to second story." src="https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438143/original/file-20211216-13-fq1fxz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Ivy is climbing up the side of this house in Aberdeen, Scotland, to expose its leaves to as much sun as possible.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/2QJYU">Stuart Caie/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Other plants, like ivy, grow as vines that climb up trees, walls and fences and use them for support. Climbing vines may grow straight, to the side or at angles, depending on what kinds of support structures they find to grow on. The purpose is to expose their leaves to as much sunlight as possible.</p>
<p>In my recent book, “<a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674241282">Lessons from Plants</a>,” I explore how plants are usually positioning themselves to see the light. It’s fascinating that we humans, too, are often positioning ourselves to see something interesting. </p>
<p>So the next time you see a plant growing straight, take notice of whether light is directly above it. Or if you see a plant that’s not straight, notice whether it’s bending toward light coming from the direction it’s facing. Or maybe it’s a vine climbing on a structure and using that support to take a different route toward the sun.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/169337/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beronda L. Montgomery receives funding from National Science Foundation, grant no. MCB-1515002 to BLM.</span></em></p>Plants need light to feed themselves, so they grow in ways that help them collect as much of it as they can. Sometimes that’s straight up, but not always.Beronda L. Montgomery, Professor of Biochemistry and Molecular Biology & Microbiology and Molecular Genetics, and Assistant Vice President of Research & Innovation, Michigan State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1747522022-01-12T13:38:21Z2022-01-12T13:38:21ZFive fascinating insights into the inner lives of plants<figure><img src="https://images.theconversation.com/files/440454/original/file-20220112-25-zmd311.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7289%2C4772&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-plant-growing-sunlight-609086588">Romolo Tavani/Shutterstock</a></span></figcaption></figure><p>Approximately 4.5 billion years ago, Earth’s land surface was barren and devoid of life. It would take another 2 billion years for the first single-celled organisms to appear in the ocean, including the first algae <em><a href="http://www.jsjgeology.net/Grypania-spiralis.htm">Grypania spiralis</a></em>, which was about the size of a 50 pence piece.</p>
<p>Plants composed of many cells have only been around for a mere 800 million years. To survive on land, plants had to protect themselves from UV radiation and develop spores and later seeds which allowed them to disperse more widely. These innovations helped plants become one of the most influential lifeforms on Earth. Today, plants are found in every major ecosystem on the planet and scientists describe more than 2,000 new species every year.</p>
<p>David Attenborough’s new documentary <a href="https://www.bbc.co.uk/programmes/m0013cl7">The Green Planet</a> casts the spotlight on plants and their ability to inspire us. In just one recent example, engineers have successfully mimicked the shape of winged maple seeds <a href="https://www.semanticscholar.org/paper/Maple-Seed-Performance-as-a-Wind-Turbine-Holden-Caley/4f5e2060500f2cd06ab63bbdf74024fdbf0c0f16">to design</a> new wind turbines.</p>
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<p>Plants retain many secrets which scientists have yet to discover. But here are five discoveries which helped us see our distant green cousins in a new light.</p>
<h2>1. Plants ‘talk’ to each other</h2>
<p>Of course, plants do not possess vocal cords and so cannot talk like we do. But they do use chemical and electronic signals to coordinate responses to their environment.</p>
<p>When plant cells are damaged, like grass cut by a lawnmower, they release protein fragments which can be detected by surrounding plants. It’s like a neighbourhood watch system: when one plant is harmed, the others are notified that there is danger nearby. This can trigger an immune response or other defences.</p>
<p>Similarly, plants can detect pollinators in their vicinity and release chemicals to attract them. These signals make plants very complex communicators.</p>
<figure class="align-center ">
<img alt="A tropical flowering plant covered in large, green ants." src="https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Plants can attract insects to do their bidding.</span>
<span class="attribution"><span class="source">Thom Dallimore</span>, <span class="license">Author provided</span></span>
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</figure>
<h2>2. Plants can move</h2>
<p>In his seminal book <a href="https://www.cambridge.org/core/books/power-of-movement-in-plants/9B9B104AB3638E43936A34F1FB73E393">The Power of Movement in Plants</a>, published in 1880, Charles Darwin described the ability of plants to move away or towards light. Scientists call this phototropism. Plant movements are now known to not only be guided by light, but also water, nutrients and in response to grazing by animals and competition from other plants. </p>
<p>Plants may appear frozen in place, destined to remain where their seeds germinate. But in fact, plants constantly adjust their leaves, roots and stems to improve their chances of survival. For example, the shaded sides of stems always grow longer to ensure the plant grows towards light in a process mediated by hormones. Roots show the opposite effect, causing them to grow away from the light. </p>
<p>In some extreme cases, plants can even move across an entire forest. Nomadic vines grow upwards from the bottom of a tree trunk then detach from the soil. Later, they put down aerial roots and descend again, allowing them to <a href="https://www.jstor.org/stable/2261006?seq=1#metadata_info_tab_contents">move between trees</a>.</p>
<h2>3. Plants can grow in outer space</h2>
<p>The idea of traversing space and living on other planets has long excited the human imagination. But no planets with the same environment as Earth have been found. We know plants are experts at modifying environments to suit the needs of more complex life. As early forests began photosynthesising, they oxygenated Earth’s atmosphere and drew down CO₂, making the planet more hospitable.</p>
<p>Could growing plants on distant planets make them more suitable to our needs? During the space race between the USSR and the US in the 1950s and 1960s, scientists studied how plants grow and develop in space. So far, scientists have grown 17 different species of plants in specialised chambers, including crops like <a href="https://www.nasa.gov/feature/nasa-astronaut-paints-a-picture-of-success-growing-plants-in-space">corn, wheat, tomatoes and lettuce</a>. Big challenges to growing Earth’s plants outside our atmosphere remain, including radiation during space flight and differences in gas movements in space compared to Earth. If you think it’s hard to keep a plant alive at home, try doing it in space.</p>
<p>The ability to terraform a planet – making it suitable for humans to live on – remains elusive. But major progress in plant science over the last few years make this an achievable target, perhaps within the lifetime of people alive today.</p>
<h2>4. One in ten plants grow on other plants</h2>
<p>Often towering tens of metres tall are some of the largest organisms on the planet. Redwood trees, for example, can grow over 100 metres tall. Scientists first began studying their lofty forest canopies by training monkeys or employing skilled climbers to collect samples. Some even used shotguns to shoot down samples. </p>
<p>It was not until the 1980s that canopy research became a scientific discipline in its own right, with the use of rope climbing techniques borrowed from mountaineering. Later, cranes, balloons and drones joined the toolset of many scientists. But why risk your life to climb a tree? What’s up there? </p>
<p>It’s estimated that up to <a href="https://www.sciencedirect.com/science/article/pii/S0169534717300599">80% of species</a> in a forest either use or live their entire lives in the forest canopy. One in ten of all known species of vascular plants – species which use vein-like vessels to transport water and nutrients throughout their body – grow on top of other plants. </p>
<figure class="align-center ">
<img alt="A tree whose bark is concealed by green and fuzzy plants growing on its surface." src="https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A tree in Papua New Guinea covered in epiphytic ferns and orchids.</span>
<span class="attribution"><span class="source">Thom Dallimore</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These are called epiphytes. They are not parasites, but instead use their host for physical support. This gives them an advantage over plants growing in the forest understorey, where light is scarce. Most orchids grow on trees and a single tree can hold as many as 50 species of epiphyte. Often, these epiphytes put out more leaves than their host tree. </p>
<h2>5. Plants can indicate global change</h2>
<p>Organisms are very sensitive to changes in their environment and plants in particular have been used to detect these changes for centuries. When leaves start to change colour in autumn, it usually heralds the arrival of cooler and darker months. </p>
<p>Certain species of ferns are particularly vulnerable to changes in their local climate. Filmy ferns grow in shaded regions of tropical forests, usually near the bases of trees or on wet rocks. They rely on water and low temperatures, and are good indicators of oncoming drought and rising temperatures.</p>
<p>Since the 1980s, the global average temperature has been rising as a direct result of burning fossil fuels like coal, which was deposited by plants millions of years ago during the early formation of forests. We are living in a time of change and understanding how plants respond to changes in climate can help us to prepare ourselves for the future.</p><img src="https://counter.theconversation.com/content/174752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sven Batke does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>David Attenborough’s new BBC documentary The Green Planet shows plants are stranger than they first appear.Sven Batke, Lecturer in Biology, Edge Hill UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1602682021-11-10T04:21:56Z2021-11-10T04:21:56ZOil, wood, bark, exploitation: a new exhibition explores human relations with the Eucalyptus<figure><img src="https://images.theconversation.com/files/430709/original/file-20211108-69725-7j3red.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Collection of timber samples from the Powerhouse Museum’s historic collection, 1886-1932. </span> <span class="attribution"><span class="source">Zan Wimberley</span></span></figcaption></figure><p>The Eucalyptus tree smells like minty life. Its branches bend and wrap like human arms, its scribbly or papery bark cries out to be touched and it emits a blue, oily haze. It would be hard to find an Australian who hasn’t sat beneath its shady canopy, tugged at its leaves to squeak out a tune, or used its oil to minimise a congested cold.</p>
<p>Eucalyptusdom, a multi-sensory exhibition of museum collection objects and new artworks at Sydney’s Museum of Applied Arts and Sciences, is a testament to the utilitarian and cultural life of the tree.</p>
<p>Plant science tells us that <a href="https://www.smithsonianmag.com/science-nature/the-whispering-trees-180968084/">trees emit chemicals</a> and gases to communicate with one another, that they spread their roots across astonishing distances and share nutrients via mycelium that spread information to other trees, often from a mother tree to smaller saplings. This adds to cultural and philosophical knowledge that connects with the animism and independent agency of the tree.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/you-dont-have-to-be-barking-to-think-trees-are-like-us-38232">You don't have to be barking to think trees are like us</a>
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</em>
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<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=466&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=466&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=466&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=586&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=586&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430707/original/file-20211108-25-1yplrxb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=586&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hand-coloured photographic transparency, one of eight depicting various aspects of research and industry related to Eucalyptus oil distillation in Australia, circa 1880–1960.</span>
<span class="attribution"><span class="source">Powerhouse Collection</span></span>
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</figure>
<p>While this exhibition celebrates human relations with the Eucalyptus, rather than the tree’s own nonhuman life, it does other things such as walking the tightrope towards decolonising the museum’s collection.</p>
<p>This is important work. It refers to (re)telling stories of Aboriginal culture and often means admitting the truth about how museum objects were collected, classified, named and curatorially interpreted, sometimes in culturally insensitive ways.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=411&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=411&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=411&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=517&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=517&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430704/original/file-20211108-10010-rp96b5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=517&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mittji by Wukun Wanambi, commissioned for the exhibition Eucalyptusdom, acquired 2021.</span>
<span class="attribution"><span class="source">Zan Wimberley</span></span>
</figcaption>
</figure>
<p>The exhibition also includes three important Australian cultural figures: the poetic writer Ashley Hay who has <a href="https://www.newsouthbooks.com.au/books/gum-131849/">written a book called Gum</a>, the great artist <a href="https://profiles.uts.edu.au/Jonathan.Jones">Jonathan Jones</a>, and revered Australian architect <a href="https://www.ozetecture.org/richard-leplastrier-projects">Richard Lepastrier AO</a>. </p>
<p>Lepastrier co-designed the exhibition and Hay has contributed literary writings to replace exhibition labels, which have long been criticised for their didactic, androcentric and eurocentric tone. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430703/original/file-20211108-9947-15hujws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">View of Eucalyptusdom, showing the exhibition’s architectural design, developed in collaboration between Richard Leplastrier AO, Jack Gillmer (Worimi, Biripi Nations) of SJB, Adam Haddow of SJB and Vania Contreras, spatial designer.</span>
<span class="attribution"><span class="source">Zan Wimberley</span></span>
</figcaption>
</figure>
<p>And then there is Jones, who has created yet another installation to stop viewers in their tracks. It’s in a side room of the exhibition, which has the unfortunate effect of seeming like an afterthought, but reverberates with his subtle and finessed (re)presentation of Australian Indigenous history. </p>
<p>On the walls hang eight ink drawings: thick with representations of ceremonial smoke and explained as sentinels. In the centre of the room is a pile of traditional tools, more like a pyre, made from mandang (wood), alongside piles of gum leaves. Jones, a Wiradjuri and Kamilaroi artist, collaborated with Wiradjuri man, Dr Uncle Stan Grant, to create this work, which includes a sound component.</p>
<p>The pyre is bleached and pale and connects to guardian ancestor Dharramalin, who is central to men’s business. The soundscape presents as the ancestor voice, a roar of thunder and animalistic, aggressive power.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/renewable-jet-fuel-could-be-growing-on-australias-iconic-gum-trees-59377">Renewable jet fuel could be growing on Australia's iconic gum trees</a>
</strong>
</em>
</p>
<hr>
<p>Other commissioned Indigenous artworks and soundscapes in this exhibition, include textiles and wearable garments (one made of bark), alongside objects such as jars of eucalyptus sap, tapestry and video portraits.</p>
<p>There are also glass plate photographs of settlers felling eucalyptus trees; more than 100 eucalyptus wood specimens from the 1800s collected by the museum and various botanists; painted porcelain plates depicting eucalypts and letters and receipts regarding economic botany from London’s Kew Gardens. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430706/original/file-20211108-9947-1pafxme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Porcelain plates, designed by Marian Ellis Rowan, Melbourne, made by.
Worcester Royal Porcelain Company Ltd, 1910-14.</span>
<span class="attribution"><span class="source">Powerhouse Collection</span></span>
</figcaption>
</figure>
<p>These historically fascinating objects draw a story of settler culture but also lay bare the absence of Indigenous stories therein.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mountain-ash-has-a-regal-presence-the-tallest-flowering-plant-in-the-world-96021">Mountain ash has a regal presence: the tallest flowering plant in the world</a>
</strong>
</em>
</p>
<hr>
<h2>Decolonising plants</h2>
<p>This exhibition presents current and ongoing discussions in “botanical aesthetics”, where plant or tree stories from the settler past sit in (dis)harmony with Indigenous truths and cultural knowledge.</p>
<p>This extends to a wider debate about decolonising plants: understanding the institutional practices that informed and still exist in herbaria, such as following <a href="https://www.britannica.com/science/taxonomy/Classification-since-Linnaeus">Linnaean naming systems</a> (Latin and common names) without acknowledging Indigenous names.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430705/original/file-20211108-19-1lwb6np.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Collection of timber samples from the Museum’s historic collection, 1886-1932.</span>
<span class="attribution"><span class="source">Zan Wimberley</span></span>
</figcaption>
</figure>
<p>It reminds audiences of the absence of information regarding the Indigenous botanical collectors who guided the colonial botanists to their rare and bountiful specimens. It refers to the imperial colonial history of malevolent and strident plant collecting that wrought damage to lands and peoples across the world.</p>
<p>Eucalyptusdom is a theatre of colonial collecting but also an introduction to exciting Indigenous artworks. It works as an instruction on how to decolonise plants, in this case the Eucalyptus tree.</p>
<p>While it doesn’t completely escape the subtle dangers of re-colonising the objects and artworks – there is not much dialogue or critique between them – nevertheless, it is a heady and immersive vegetal experience.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430712/original/file-20211108-23-qd59dw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">View of Eucalyptusdom showing commissioned work, Let Me Pass Onto You by Vera Hong in background and a collection of carved timber objects from the Museum’s historic collection in the foreground.</span>
<span class="attribution"><span class="source">Zan Wimberley</span></span>
</figcaption>
</figure>
<p>Economic botany and colonial botanical curiosity are marked in the exhibition by a cabinet of glass jars containing barks and kinos (a gum-like oozing substance from the tree). These were collected under the direction of Joseph Maiden, director of Sydney’s Royal Botanical Gardens in the late 19th century.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430734/original/file-20211108-9517-1neo1n3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Timber Court, Australian Flora, Technological Museum, Harris Street, Ultimo c1908.</span>
<span class="attribution"><span class="source">Powerhouse Collection</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/photos-from-the-field-capturing-the-grandeur-and-heartbreak-of-tasmanias-giant-trees-144743">Photos from the field: capturing the grandeur and heartbreak of Tasmania's giant trees</a>
</strong>
</em>
</p>
<hr>
<p>Such specimens are the perfect reminder of the problems of decolonising collections because they are exquisite objects of aesthetic desire. I don’t know anyone who would want them destroyed or locked away. They feed a human (mostly western) desire to gather, to sort, to order and to name.</p>
<p>The joy of ordering objects is a way of ordering thoughts, for some of us. However, collecting has a violent colonial history and it still feels uncomfortable to view them alongside new Indigenous artworks that work to redress that violence.</p>
<p>This discomfort is perhaps the exhibition’s greatest strength. It reminds those of us who are tree-lovers and/or plant-mad that we have responsibilities to respect the Eucalyptus and to acknowledge that Indigenous people always knew this tree.</p>
<p><em>Eucalyptusdom is at The Powerhouse until May 2022.</em></p><img src="https://counter.theconversation.com/content/160268/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Prudence Gibson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Eucalyptusdom is a testament to the utilitarian and cultural life of a remarkable tree.Prudence Gibson, Author and Research Fellow, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1692412021-10-05T00:20:36Z2021-10-05T00:20:36ZWhy sweet-toothed possums graze on stressed, sickly-looking trees<figure><img src="https://images.theconversation.com/files/424590/original/file-20211004-19-ac5yb.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5463%2C3637&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>From time to time, I’m contacted by people who have a favourite garden tree that seems suddenly to be in serious decline and lacking healthy foliage. Often the decline has been occurring over many months, but when first noticed, the change seems to have been dramatic.</p>
<p>The symptoms described accord with grazing — where animals nibble at foliage until it’s quite degraded — so I ask if they have seen brushtail possums in the tree. </p>
<p>More often than not the answer is a firm, “No!” </p>
<p>However, just because you haven’t seen them, it doesn’t mean the possums aren’t there. One owner, who said they weren’t aware of any possums, checked at night with a torch; they counted 56 possums in a single, sick-looking river red gum.</p>
<p>It’s not uncommon for one tree within a group of the same species to be grazed while other trees are left alone. </p>
<p>In the early evening, a steady stream of possums can be seen coming from all directions and from nesting sites in other trees hundreds of metres away, all homing in on the one sickly specimen.</p>
<p>To the human eye, this seems very strange behaviour. Wouldn’t the possums be better off grazing on a healthy tree? </p>
<p>But possums are real tree experts and know exactly what they are doing.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A mother and baby possum in a tree." src="https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424592/original/file-20211004-12705-1sc0487.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Possums are real tree experts and know exactly what they are doing.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-if-trees-are-cut-down-in-the-city-where-will-possums-live-161810">Curious Kids: if trees are cut down in the city, where will possums live?</a>
</strong>
</em>
</p>
<hr>
<h2>It’s all about the sugar content</h2>
<p>The common brushtail possum, <em>Trichosurus vulpecula</em>, will eat both plants and small animals if given the chance, but plants form the bulk of their <a href="https://environment.des.qld.gov.au/wildlife/animals/a-z/common-brushtail-possum">diet</a>. Eucalypt leaves are a favourite, but they’ll nibble the leaves of other plants in our gardens.</p>
<p>So what is going on when one tree is grazed in preference to others? One of the main drivers revolves around sugar. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A possum is in a gum tree." src="https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424591/original/file-20211004-19-jey76j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Eucalypt leaves are a favourite for possums.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>When plants photosynthesise, one of the first products of the process is sugar. Sugars are carbohydrates made up of carbon, hydrogen and oxygen atoms and one of the most common is glucose (C₆H₁₂O₆), which is the common sugar used in coffee, tea and cooking.</p>
<p>Sugar may be copping a bit of stick at present for its role in human diets, but in terms of plant metabolism, glucose is a marvellous molecule. </p>
<p>It is made from simple and ready available ingredients. It is soluble in water and can be easily transported around inside the plant. And it stores significant energy.</p>
<p>This makes it a very accessible and desirable molecule within the plant, but too much glucose in solution can cause problems for the plant and <a href="https://www.mytutor.co.uk/answers/51774/GCSE/Biology/Why-do-plants-convert-glucose-to-starch-in-photosynthesis/">attract grazers</a> keen on an easy sugar hit.</p>
<p>The plant has evolved an elegant solution to these problems. It simply takes two or more glucose molecules and bonds them together to make starch‚ which is not very soluble in water, contains lots of energy and so is an ideal storage form of carbohydrate. </p>
<p>The plant converts any excess glucose that it has into <a href="https://sciencing.com/where-is-starch-stored-in-plant-cells-12428011.html">starch</a> for later use when things might be tougher.</p>
<h2>What’s this got to do with possums, again?</h2>
<p>When a plant is stressed, one of its first responses is to mobilise its resources. Among other things, it often converts its starch reserves back to sugar. As soon as this happens, the stressed plant becomes sweeter than its healthier neighbours — and brushtail possums know it.</p>
<p>Some stressed trees emit <a href="https://research.libraries.wsu.edu/xmlui/bitstream/handle/2376/983/v75sp%20p70%20Kelsey.PDF?sequence=1">chemicals</a> that can be picked up by grazers. In other cases, the grazers may come upon a stressed tree by chance. </p>
<p>In either case, the grazer gets an increased sugar hit and so will return to the tree when the opportunity presents; other grazers may follow. </p>
<p>In the case of brushtail possums, a possum may return to the same tree night after night and, despite territorial disputes, may be joined by other possums in a feeding feast.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A possum is in a tree." src="https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424594/original/file-20211004-25-1t6wmew.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Plants form the bulk of the possum diet.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A stressed tree is a grazer’s delight</h2>
<p>Initially, the tree may have been stressed by drought, poor nutrition or waterlogged soils. The increased grazing then adds to the level of stress. </p>
<p>And when lots of leaves are removed, many trees such as eucalypts, elms, oaks and even deciduous conifers will respond by producing new leaves and shoots. These lovely new leaves and shoots are soft and loaded with sugars — a grazer’s delight.</p>
<p>With more stress, the tree converts more and more starch into sugar and produces yet more new leaves and shoots — so the <a href="https://www.doc.govt.nz/documents/science-and-technical/everybodyspossum.pdf">grazers</a> get a sweet and nutritious reward for their efforts. They will keep returning to the same tree.</p>
<p>All of this extra grazing comes at a price to the tree, which is exhausting its starch reserves, but getting little or no reward from the sugar produced.</p>
<p>Eventually, the tree will succumb. It may die from starvation due to the loss of its reserves and the failure of new foliage to survive long enough to photosynthesise. Or it may die from another environmental stress or a pest or disease attack.</p>
<p>Grazing can be lethal to a tree, but you can see why the grazers keep coming back. </p>
<p>Stressed trees are an easy and rewarding energy source. Perhaps, like us, the possums become addicted to a high sugar diet and simply can’t resist returning to the tree — even if, in the end, the tree is grazed to death.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hidden-housemates-when-possums-go-bump-in-the-night-57478">Hidden housemates: when possums go bump in the night</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/169241/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When a plant is stressed, it mobilises its resources and often converts its starch reserves back to sugar. As soon as this happens, the stressed plant becomes sweeter than its healthier neighbours.Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1673742021-09-10T03:21:42Z2021-09-10T03:21:42ZThe daily dance of flowers tracking the sun is more fascinating than most of us realise<figure><img src="https://images.theconversation.com/files/420390/original/file-20210910-21-16krrwb.jpg?ixlib=rb-1.1.0&rect=18%2C6%2C4174%2C2785&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Julien Christ/Unsplash</span></span></figcaption></figure><p>When I was a child, I was intrigued by <a href="https://www.anbg.gov.au/cpbr/cd-keys/RFK7/key/RFK7/Media/Html/entities/Lophostemon_confertus.htm">the Queensland box</a> (<em>Lophostemon confertus</em>) growing in our backyard. I noticed its leaves hung vertical after lunch in summer, and were more or less horizontal by the next morning. </p>
<p>This an example of heliotropism, which literally means moving in relation to the sun. We can see it most clearly as spring arrives and various species burst into flower — you might even get the feeling that some flowers are watching you as they move.</p>
<p>Many of us probably first got to know of heliotropism at home, kindergarten or primary school by watching the enormous yellow and black flowering heads of aptly name sunflowers, which moved as they grew. </p>
<p>These flowers track the course of the sun spectacularly on warm and sunny, spring or summer days. Sometimes they move through an arc of almost 180⁰ from morning to evening. </p>
<p>So with the return of sunny days and flowers in full bloom this season, let’s look at why this phenomenon is so interesting. </p>
<h2>The mechanics of tracking the sun</h2>
<p>A number <a href="https://echelonflorist.com/flower-talk/lessons-flowers-facing-sun-phototropic-plants/">flowering species</a> display heliotropism, including alpine buttercups, arctic poppies, alfalfa, soybean and many of the daisy-type species. So why do they do it?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420395/original/file-20210910-27-1px5oh7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is <em>Heliotropium arborescens</em>, named for its heliotropism. They were very popular in gardens a century or more ago, but have fallen from favour as they can be poisonous and weedy.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Flowers are really in the advertising game and will do anything they can to attract a suitable pollinator, as effectively and as efficiently as they can. There are several <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/heliotropism">possible reasons</a> why tracking the sun might have evolved to achieve more successful pollination. </p>
<p>By tracking the sun, flowers absorb more solar radiation and so <a href="http://lifeofplant.blogspot.com/2011/03/heliotropism.html">remain warmer</a>. The warmer temperature suits or even rewards insect pollinators that are more active when they have a higher body temperature. </p>
<p>Optimum flower warmth may also boost pollen development and germination, leading to a higher fertilisation rate and more seeds. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-theres-a-lot-more-to-love-about-jacarandas-than-just-their-purple-flowers-150851">Why there's a lot more to love about jacarandas than just their purple flowers</a>
</strong>
</em>
</p>
<hr>
<p>So, the flowers are clearly moving. But how? </p>
<p>For many heliotropic flowering species, there’s a special layer of cells called the pulvinus <a href="https://depts.washington.edu/cims/research/Bio-Intelligent-Materials.pdf">just under the flower heads</a>. These cells pump water across their cell membranes in a controlled way, so that cells can be fully pumped up like a balloon or become empty and flaccid. Changes in these cells allow the flower head to move.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Venus fly trap" src="https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420399/original/file-20210910-13-yn5t11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fly traps have somewhat similar mechanics to heliotropism.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>When potassium from neighbouring plant cells is moved into the cells of the pulvinus, water follows and the cells inflate. When they move potassium out of the cells, they become flaccid. </p>
<p>These potassium pumps are involved in many other aspects of plant movement, too. This includes the opening and closing of stomata (tiny regulated leaf apertures), the rapid movement of mimosa leaves, or the closing of a fly trap. </p>
<h2>But sunflowers dance differently</h2>
<p>In 2016, <a href="https://www.npr.org/sections/thetwo-way/2016/08/05/488891151/the-mystery-of-why-sunflowers-turn-to-follow-the-sun-solved">scientists discovered</a> that the pin-up example of heliotropism — the sunflower — had a different way of moving. </p>
<p>They found sunflower movement is due to significantly different growth rates on opposite sides of the flowering stem. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sunflower facing a setting sun" src="https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420389/original/file-20210910-15-1q475ls.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sunflowers move differently to other heliotropic flowers.</span>
<span class="attribution"><span class="source">Aaron Burden/Unsplash</span></span>
</figcaption>
</figure>
<p>On the east-facing side, the cells grow and elongate quickly during the day, which slowly pushes the flower to face west as the daylight hours go by — following the sun. At night the west-side cells grow and elongate more rapidly, which pushes the flower back toward the east over night. </p>
<p>Everything is then set for the whole process to begin again at dawn next day, which is repeated daily until the flower stops growing and movement ceases. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-secret-life-of-puddles-their-value-to-nature-is-subtle-but-hugely-important-154561">The secret life of puddles: their value to nature is subtle, but hugely important</a>
</strong>
</em>
</p>
<hr>
<p>While many people are aware of heliotropism in flowers, heliotropic movement of leaves is less commonly noticed or known. Plants with heliotropic flowers don’t necessarily have heliotropic leaves, and vice versa. </p>
<p>Heliotropism evolves in response to highly specific environmental conditions, and factors <a href="https://www.scienceabc.com/nature/sunflowers-always-face-follow-sun.html">affecting flowers</a> can be different from those impacting leaves. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420401/original/file-20210910-25-2xp1vf.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The leaves of Queensland box, <em>Lophostemon confertus</em>, which track the sun.</span>
<span class="attribution"><span class="source">Krzysztof Ziarnek, Kenraiz/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>For example, flowers are all about pollination and seed production. For leaves, it’s for maximising photosynthesis, avoiding over-heating on a hot day or even reducing water loss in harsh and arid conditions.</p>
<p>Some species, such as the Queensland box, arrange their leaves so they’re somewhat horizontal in the morning, capturing the full value of the available sunlight. But there are also instances where leaves align vertically to the sun in the middle of the day to minimise the risks of heat damage.</p>
<h2>Plants are dynamic</h2>
<p>It’s easy to think of plants as static organisms. But of course, they are forever changing, responding to their environments and growing. They are dynamic in their own way, and we tend to assume that when they do change, it will be at a very slow and steady pace.</p>
<p>Heliotropism shows us this is not necessarily the case. Plants changing daily can be a little unsettling in that we sense a change but may not be aware of what is causing our unease. </p>
<p>As for me, I still keep a watchful eye on those Queensland boxes!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/it-is-risen-the-story-of-resurrection-ferns-and-my-late-colleague-who-helped-discover-them-in-australia-157775">It is risen: the story of resurrection ferns and my late colleague who helped discover them in Australia</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/167374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The phenomenon is called heliotropism, and sunflowers are most famous for it. But why do they track the sun? And how?Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1659732021-08-23T20:10:20Z2021-08-23T20:10:20ZCockatoos and rainbow lorikeets battle for nest space as the best old trees disappear<figure><img src="https://images.theconversation.com/files/417171/original/file-20210820-19-18i0nus.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C3888%2C2580&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The housing market in most parts of Australia is notoriously competitive. You might be surprised to learn we humans are not the only ones facing such difficulties.</p>
<p>With spring rapidly approaching, and perhaps a little earlier due to climate change, many birds are currently on the hunt for the best nesting sites. </p>
<p>This can be hard enough for birds that construct nests from leaves and twigs in the canopies of shrubs and trees, but imagine how hard it must be for species that nest in <a href="https://www.environment.nsw.gov.au/resources/nature/Factsheet5TreeHollows.pdf">tree hollows</a>. </p>
<p>They are looking for hollows of just the right size, in just the right place. Competition for these prime locations is cut-throat.</p>
<h2>Sulphur-crested cockatoos battling for spots</h2>
<p><a href="https://backyardbuddies.org.au/backyard-buddies/sulphur-crested-cockatoo/">Sulphur-crested cockatoos</a>, <em>Cacatua galerita</em>, are relatively large birds, so naturally the hollows they nest in need to be quite large. </p>
<p>Unfortunately, large hollows are <a href="https://theconversation.com/dont-disturb-the-cockatoos-on-your-lawn-theyre-probably-doing-all-your-weeding-for-free-154265">only found in old trees</a>.</p>
<p>It can take 150 years or more before the hollows in the eucalypts that many native parrot species nest in are large enough to accommodate nesting sulphur-crested cockatoos. Such old trees are becoming rarer as old trees on farms die and old trees in cities are cleared for urban growth.</p>
<p>In late winter, early spring you quite often find sulphur crested-cockatoos squabbling among themselves over <a href="https://www.ari.vic.gov.au/__data/assets/pdf_file/0024/328191/Nest-box-fact-sheet-general-guide.pdf">hollows in trees</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A cockatoo sits in a hollow." src="https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417183/original/file-20210820-15-xxomtp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It can take 150 years or more before the hollows in the eucalypts that many native parrot species nest in are large enough to accommodate nesting sulphur-crested cockatoos.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>These squabbles can be very loud and raucous. They can last from a few minutes to over an hour, if the site is good one. Once a pair of birds takes possession and begins nesting, they defend their spot and things tend to quieten down. </p>
<p>The stakes are high, because sulphur-crested cockatoos <a href="https://www.researchgate.net/publication/248902220_Overlap_and_competition_for_nest_holes_among_Eclectus_Parrots_Palm_Cockatoos_and_Sulphur-Crested_Cockatoos">cannot breed</a> if they don’t have a nesting hollow.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dont-disturb-the-cockatoos-on-your-lawn-theyre-probably-doing-all-your-weeding-for-free-154265">Don't disturb the cockatoos on your lawn, they're probably doing all your weeding for free</a>
</strong>
</em>
</p>
<hr>
<h2>Enter the rainbow lorikeets</h2>
<p>In parts of southeastern Australia, <a href="https://www.birdlife.org.au/bird-profile/rainbow-lorikeet">rainbow lorikeets</a>, <em>Trichoglossus moluccanus</em> (and/or <em>Trichoglossus haematodus</em>), have expanded their range over the past couple of decades. It is not uncommon to see sulphur-crested cockatoos in dispute with them over a hollow.</p>
<p>The din can be deafening and if you watch you will see both comedy and drama unfold. The sulphur-crested cockatoos usually win and drive the lorikeets away, but all is not lost for the lorikeets. </p>
<p>Sometimes the hollows prove unsuitable — usually if they are too small for the cockatoos — and a few days later the lorikeets have taken up residence. Larger hollows are rarer and so more highly prized.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A rainbow lorikeet shelters in the hollow of a tree." src="https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417173/original/file-20210820-27-1tm0503.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It is not uncommon to see sulphur-crested cockatoos in dispute with rainbow lorikeets over a hollow.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>How hollows form</h2>
<p>Many hollows begin at the stubs of branches that have been shed either as part of the tree’s growth cycle or after storm damage. The wood at the centre of the branch often lacks <a href="https://www.environment.nsw.gov.au/resources/nature/Factsheet5TreeHollows.pdf">protective defences</a> and so begins to decay while the healthy tree continues to grow over and around the hollow. </p>
<p>Other hollows develop after damage to the trunk or on a large branch, following lightning damage or insect attack. Parrots will often peck at the hollow to expand it or stop it growing over completely. Just a bit of regular home maintenance.</p>
<p>Sulphur-crested cockatoos can often be seen pecking at the top of large branches on old trees, where the branch meets the trunk. They can do considerable damage. When this area begins to decay, it can provide an <a href="https://treenet.org/resources/how-much-do-you-need-vascular-connection-between-roots-and-crown/">ideal hollow</a> for future nesting.</p>
<p>Sadly, for the cockatoo, it may take another century or so and the tree might shed the limb in the interim. Cockatoos apparently play a long game and take a very long term perspective on future nesting sites.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A cockatoo sits in a hollow." src="https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=644&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=644&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417187/original/file-20210820-23-1bqcje5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=644&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Every effort must be made to ensure old, hollow-forming trees are preserved.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Which trees are best for hollows?</h2>
<p>In watching the local battles for parrot nesting sites, some tree species are the scenes of many a conflict. </p>
<p>Sugar gums, <em><a href="https://vicflora.rbg.vic.gov.au/flora/taxon/e03f7916-3683-4b87-b9b0-3043b9ccc72d">Eucalyptus cladocalyx</a></em>, were widely planted as wind breaks in southern Australia and they were often lopped to encourage a bushier habit that provided greater shade. </p>
<p>Poor pruning often leads to hollows and cavities, which are now proving ideal for nesting — but it also resulted in poor tree structure. Sugar gums are being removed and <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059332">nesting sites lost</a> in many country towns and peri-urban areas (usually the areas around the edges of suburbs with some remaining natural vegetation, or the areas around waterways).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A rainbow lorikeet hides in a hollow." src="https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417186/original/file-20210820-13-r3hhz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many species need hollows for nests.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Old river red gums, <em>(Eucalyptus camaldulensis)</em> growing along our creeks and rivers are also great nesting sites. They are so big they provide <a href="http://theconversation.com/the-river-red-gum-is-an-icon-of-the-driest-continent-118839">ideal sites</a> for even the largest of birds.</p>
<p>These, too, are ageing and in many places are declining as riverine ecosystems suffer in general. Even the old elms, <em>Ulmus</em>, and London plane trees, <em>Platanus x acerifolia</em> — which were once lopped back to major branch stubs each year, leading hollows to develop — are disappearing as they age and old blocks are cleared for townhouses.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-river-red-gum-is-an-icon-of-the-driest-continent-118839">The river red gum is an icon of the driest continent</a>
</strong>
</em>
</p>
<hr>
<h2>Protecting tree hollows</h2>
<p>Cavities in trees are not that common. Large cavities are especially valuable assets. They are essential to maintaining biodiversity because <a href="https://www.environment.nsw.gov.au/resources/nature/Factsheet5TreeHollows.pdf">it is not just birds</a>, but mammals, reptiles, insects and arachnids that rely on them for nesting and refuge. </p>
<p>If you have a tree with a hollow, look after it. And while some trees with hollows might be hazardous, most are not. Every effort must be made to ensure old, hollow-forming trees are preserved. Just as importantly, we must allow hollow-forming trees to persist for long enough to from hollows.</p>
<p>We consider our homes to be our castles. Other species value their homes just as highly, so let’s make sure there are plenty of tree hollows in future.</p><img src="https://counter.theconversation.com/content/165973/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Spring is rapidly approaching and many birds are hunting for the best nesting sites. Competition is fierce — especially for species that nest in tree hollows.Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1614282021-07-01T19:53:48Z2021-07-01T19:53:48ZFriday essay: trees have many stories to tell. Is this our last chance to read them?<figure><img src="https://images.theconversation.com/files/407390/original/file-20210621-35631-mvc3ec.jpg?ixlib=rb-1.1.0&rect=34%2C13%2C4566%2C3062&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://images.unsplash.com/photo-1509414556967-312906f278a0?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1048&q=80">Unsplash/David Clode</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>As tree scientist, I am fascinated by the magnificent biology of trees. I also find it enthralling and encouraging that trees are being <a href="https://www.theguardian.com/stage/2021/jun/24/call-the-copse-the-sudden-flourishing-of-culture-about-trees">appreciated by writers</a> around the world right now. </p>
<p>Three fresh books (chosen from a wider field of titles on the topic) exemplify how trees can be written about as more than just background or an incidental part of a landscape, but as integral to meaning. </p>
<p><a href="https://www.goodreads.com/book/show/56888808-my-forests">My Forests: Travel with Trees</a> by Janine Burke, <a href="https://www.goodreads.com/book/show/57598967-the-heartbeat-of-trees?ac=1&from_search=true&qid=ZbJsrP0kwo&rank=1">The Heartbeat of Trees</a> by Peter Wohlleben, and <a href="https://publishing.monash.edu/product/tree-story/">Tree Story</a>, a collection curated by Charlotte Day and Brian Martin — are mixed in style and content. But all make clear the close relationships between people and trees and the vital importance of those connections. </p>
<p>It is not surprising that at a time of significant climate change, where natural ecosystems around the world are being devastated and after 18 months of a global pandemic, books on trees are proving popular. </p>
<p>There is an air of desperation in these three titles. Things are changing fast, trees and forests grow slowly, we are wasting time.</p>
<h2>Hardy annuals</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="book cover trees" src="https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=985&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=985&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=985&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1238&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1238&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407370/original/file-20210621-21-x0iy57.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1238&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.abebooks.com/servlet/BookDetailsPL?bi=30895877014&searchurl=isbn%3D0048230871%26sortby%3D17&cm_sp=snippet-_-srp1-_-title1">Abe Books</a></span>
</figcaption>
</figure>
<p>Books about trees are published every year. Some are <a href="https://www.goodreads.com/en/book/show/38747850-trees">beautifully illustrated</a> with photos or <a href="https://www.goodreads.com/book/show/40537481-the-architecture-of-trees?from_search=true&from_srp=true&qid=lRoZX1zXg6&rank=1">hand-drawn images</a> of special trees in large coffee table formats. Some, like J. R. R. Tolkien’s <a href="https://www.goodreads.com/book/show/33.The_Lord_of_the_Rings?from_search=true&from_srp=true&qid=tRdQ6EK03W&rank=3">Lord of the Rings</a>, have trees and forests as characters. Tolkien <a href="https://static1.squarespace.com/static/59d68c02c534a5079b390c38/t/5c2d3e3f575d1f37b45d4750/1546468936692/the_letters_of_j.rrtolkien.pdf">told a fan</a> that his magnificent <a href="http://tolkiengateway.net/wiki/Ents">Ents</a> were “either souls sent to inhabit trees, or else were folk who slowly took the likeness of trees owing to their inborn love of trees”. </p>
<p>Tolkien’s writing, including a story collection called <a href="https://www.goodreads.com/book/show/7348.Tree_and_Leaf">Tree and Leaf</a>, reminds us of the differences between tree time and human time — we humans are hasty folk. This is something I dwell upon often.</p>
<p><a href="https://www.goodreads.com/book/show/17490.The_Faraway_Tree_Stories?ac=1&from_search=true&qid=KjcOo8dSTN&rank=3">The Magic Faraway Tree</a> by Enid Blyton was one of the first books I can recall reading where a tree played a major role and it helped set me on a path of lifelong reading and interest in botany. </p>
<p>That childhood favourite connects to Richard Powers’ <a href="https://www.goodreads.com/book/show/40180098-the-overstory">The Overstory</a>, which draws together a disparate fictional band of tree protectors. After his book became a hit, Powers <a href="https://www.pbs.org/newshour/arts/loved-the-overstory-richard-powers-recommends-26-other-books-on-trees">recommended 26 other titles</a> for tree-loving readers. </p>
<p>This library of tree books has served a wide and varied readership well and sustained those of us who despair at the wholesale clearing of forests and trees in our cities and suburbs. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-how-many-climate-crisis-books-will-it-take-to-save-the-planet-149529">Friday essay: how many climate crisis books will it take to save the planet?</a>
</strong>
</em>
</p>
<hr>
<h2>Legacies lost</h2>
<p>In most Australian cities we are losing trees and canopy cover at a rate of about <a href="https://treenet.org/resources/it-isnt-rocket-science-street-trees-can-make-a-difference-in-climate-change/">1-1.5% per year</a>. I’m still saddened by the loss of a lemon scented gum (<em>Corymbia citriodora</em>) that grew at the <a href="https://www.theage.com.au/national/victoria/parkville-residents-furious-with-plan-to-destroy-famous-tree-for-citylink-project-20160414-go69ma.html">city end of the Tullamarine Freeway</a> in Melbourne. I miss its shade in summer but also the delicious scent that wafted through the car window at certain times of the year. </p>
<p>In October last year, <a href="https://www.sbs.com.au/news/sacred-350-year-old-indigenous-tree-cut-down-for-victorian-highway-upgrade-activists-report">protesters mourned</a> a sacred 350-year-old Djab Wurrung Directions Tree, cut down along Victoria’s Western Highway.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-open-letter-from-1-200-australian-academics-on-the-djab-wurrung-trees-149147">An open letter from 1,200 Australian academics on the Djab Wurrung trees</a>
</strong>
</em>
</p>
<hr>
<p>There has been a <a href="https://www.researchgate.net/publication/315898636_A_Growing_Disconnection_From_Nature_Is_Evident_in_Cultural_Products">growing disconnect</a> between people and trees and vegetated spaces, particularly for those living in cities. Many people have become so focused on urban survival they have become distanced from the essential and intimate dependence that human beings have on plant life. </p>
<p>Earth as we know it, and the lifeforms it sustains, depend upon and have been shaped by plants and their evolution. Human beings can only survive on our planet because of the <a href="https://www.royalparks.org.uk/parks/the-regents-park/things-to-see-and-do/gardens-and-landscapes/tree-map/why-trees-are-important#:%7E:text=Trees%20are%20vital.,materials%20for%20tools%20and%20shelter.">ecosystems made possible by plants and trees</a>. If these systems are put in jeopardy because people fail to appreciate the importance of plants, then entire ecosystems are put in peril with profound consequences for humankind. </p>
<p>Climate change is <a href="https://www.abc.net.au/news/2021-06-17/tree-storm-damage-wind-event/100216056">giving us a glimpse</a> of how these important relationships are affected by bushfires, stronger winds from unusual directions and more frequent storms with heavy rainfall that can lead of the loss of grand old trees that have stood as silent sentinels for decades and centuries. </p>
<p>All plants in an ecosystem are important to its function, but the large size and long lives of trees explain why they are often focused upon as representatives of their communities. Their size makes them obvious and contributes to the ambience of any landscape, but can also inspire a sense of awe and in some urban-dwellers, fear. </p>
<p>Their long life spans provide a sense of certainly and continuity in uncertain times of rapid change — their presence can link several human generations, when other connections have been lost. They also provide a tangible prospect, if they are left alone or are properly managed, for links to future generations. All of this can be very reassuring for people who feel vulnerable and oppressed by rapid change.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-act-of-god-or-just-bad-management-why-trees-fall-and-how-to-prevent-it-162754">An act of God, or just bad management? Why trees fall and how to prevent it</a>
</strong>
</em>
</p>
<hr>
<h2>A fresh crop</h2>
<p>All three of the new books selected tend to anthropomorphise trees and aspects of their biology, attributing to them distinctly human qualities. Sometimes they are described by a mood, such as an upbeat growth in spring or by a willingness to share resources with other species. While this may be annoying to some scientists, it allows many people to relate or even identify more closely with trees, especially when there is complex biology and ecology involved. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="book cover. trees" src="https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=917&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=917&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=917&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1153&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1153&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407348/original/file-20210621-14-1lh98tn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1153&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.blackincbooks.com.au/books/heartbeat-trees">Black Inc.</a></span>
</figcaption>
</figure>
<p>Peter Wohlleben’s bestselling 2016 book <a href="https://www.goodreads.com/book/show/28256439-the-hidden-life-of-trees">The Hidden life of Trees</a>, took readers on a voyage of discovery with a blend of science, philosophy and spiritualism. </p>
<p>Like that first book, his latest — The Heartbeat of Trees — can be enthralling and annoying almost in equal measure. But the author clearly relates the importance of using our senses when we are in forests to explore the complexity of tree biology. By doing so not only will we achieve a better understanding of trees, but also of ourselves and the importance of trees and vegetated places for human development, our physical and mental health and the sustainability of our societies. It will surely resonate strongly with readers after the pandemic lockdowns of the past year, which saw people flocking to parks, gardens and forests.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="book cover trees" src="https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=918&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=918&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=918&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1153&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1153&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407349/original/file-20210621-26003-1yrc883.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1153&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.mup.com.au/books/my-forests-hardback">MUP</a></span>
</figcaption>
</figure>
<p>A personal and professional travelogue woven together by trees is the framework of My Forests: Travel with Trees, by Janine Burke. As an art historian Burke weaves her own experiences with trees with those depicted in paintings, ancient mythology and historic and literary texts. </p>
<p>It is a set of idiosyncratic connections that may not resonate with all readers, but the strong cultural links between trees and ancient human history are undeniable. The reader can learn a great deal about people but relatively little about trees themselves — they remain illusory, almost furtive.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="book cover trees" src="https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407350/original/file-20210621-35715-1ssa5cy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.mup.com.au/books/my-forests-hardback">Monash University Press</a></span>
</figcaption>
</figure>
<p>Tree Story, curated by Charlotte Day and Brian Martin catalogues a <a href="https://www.monash.edu/muma/exhibitions/previous/2022/tree-story">recent exhibition</a> at Monash University Museum of Art. It is an eclectic mix of style, content, form and media. Some of the images and text do not do justice to the works, but the book does provide a permanent and curated record of what was offered. </p>
<p>The book makes it clear that people see and connect with trees in different, varied and curious ways. While the works may look at the past, there are clear implications, messages and lessons for the present and importantly for the future. Indigenous voices and perspectives speak loudly, longingly and desperately. The works plead that we cannot go on treating trees in this way: for our own health and sustainable futures we must recognise that ultimately all earthly life is essentially one.</p>
<h2>Strengthening the bond</h2>
<p>The three books, in their own and different ways, challenge how we think about and interact with trees. They broaden the relationship that exists between trees and people and encourage an active and positive interaction. There is a unifying theme that healthy relationships will benefit both people and trees. </p>
<p>Authors and artists recount their personal stories of trees benefiting their own physical and mental well-being. Research shows that trees along streets and roadways have a traffic calming effect that results in slower speeds and more courteous driver behaviour. In a huge <a href="https://ehp.niehs.nih.gov/doi/full/10.1289/ehp.1510363">study of women’s health</a> in the United States it was shown that green spaces (parks, gardens and trees) significantly correlated with many aspects of improved health. </p>
<p>Plants and trees are not passive participants in ecosystems. They actively contribute to the complexity, resilience and survival of these systems and while the environment affects and changes them, they also modify the environment. Shade from trees cools the understorey and soils, making it possible for a more diverse range of species to thrive. Shade on creeks and rivers helps native fish survive and breed. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Felled trees" src="https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407852/original/file-20210623-23-h2e21q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Great Otways National Park.</span>
<span class="attribution"><a class="source" href="https://images.unsplash.com/photo-1602484894924-75eddc89d32b?ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80">Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-this-grandmother-tree-connects-me-to-country-i-cried-when-i-saw-her-burned-129782">Friday essay: this grandmother tree connects me to Country. I cried when I saw her burned</a>
</strong>
</em>
</p>
<hr>
<p>These books highlight the complexity of the relationships that many of us have with trees – relationships that can bring change to both us and the trees.</p>
<p>Wohlleben asks that we use all our senses when we interact with trees and forests. There is more going on than meets the eye. Burke reminds us that culture and tradition influence our perception of trees and forests. The works exhibited in Tree Story help us to explore these influences and their meaning. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Tree in forest" src="https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407855/original/file-20210623-21-1n2m0h8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The stories trees tell …</span>
<span class="attribution"><a class="source" href="https://images.unsplash.com/photo-1453791052107-5c843da62d97?ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=1050&q=80">Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We are far from knowing all there is to know about plants, trees, forests and ecosystems. The scientific approach is but one method of questing for truth. The open-minded approaches explored in these books could stimulate new discoveries.</p>
<p>The books remind us of the pace of change being wrought on trees and forests by climate change and that the stakes, if we don’t reverse this decline, are very high. </p>
<p>Scientists should never dismiss what they don’t understand. Neither should readers. As climates change, the presence of trees and green space will be recognised as a priority. Trees will be a part of our futures no matter where we live because we cannot have economically viable, environmentally sustainable or liveable places without them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman reading under a tree" src="https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407882/original/file-20210623-17-1r2ebbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Books can remind us what we have, and what’s at stake.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/middle-aged-caucasian-woman-reading-magazine-1570142479">Shutterstock</a></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/161428/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It’s no coincidence that more books about trees are popping up. There is an air of desperation in new books by Peter Wohllben, Janine Burke and others.Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.