tag:theconversation.com,2011:/uk/topics/flora-1492/articles
Flora – The Conversation
2023-10-30T19:10:53Z
tag:theconversation.com,2011:article/216006
2023-10-30T19:10:53Z
2023-10-30T19:10:53Z
We need a single list of all life on Earth – and most taxonomists now agree on how to start
<figure><img src="https://images.theconversation.com/files/556256/original/file-20231027-21-nxmtp5.jpg?ixlib=rb-1.1.0&rect=151%2C53%2C4719%2C3316&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/common-kingfisher-alcedo-atthis-wetlands-birdss-2331210013">Sumruay Rattanataipob/Shutterstock</a></span></figcaption></figure><p>Species lists are one of the unseen pillars of science and society. Lists of species underpin our understanding of the natural world, threatened species management, quarantine, disease control and <a href="https://link.springer.com/article/10.1007/s13127-021-00518-8">much else besides</a>. </p>
<p>The people who describe new species and create lists of them are taxonomists. <a href="https://www.nature.com/articles/546025a">A few years ago</a>, a headline in the journal Nature accused the taxonomic community of anarchy for not coordinating a common view of species, leading to confusion about our knowledge of life on earth.</p>
<p>Many in the taxonomic community <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2005075">took umbrage</a> at this. Taxonomists were concerned that the ideas proposed would limit their freedom of expression and they would be tied to a bureaucracy before they could publish new species descriptions.</p>
<p>Taxonomists certainly argue – disputation is <a href="https://link.springer.com/article/10.1007/s13127-021-00495-y">essential to the practice of taxonomy</a>, as it is to science in general. Ultimately, however, a taxonomist’s life is spent trying to discern order in the extraordinarily diverse tree of life.</p>
<p>The results of a new survey published today in the <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.2306899120">Proceedings of the National Academies of Science</a>, show just how much taxonomists really do like order.</p>
<h2>Hardly a group of anarchists</h2>
<p>The argument was about how to solve disagreements between taxonomists. Eventually, the <a href="https://theconversation.com/how-a-scientific-spat-over-how-to-name-species-turned-into-a-big-plus-for-nature-138887">two sides came together</a> to produce principles on the creation of a <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000736">single authoritative list of species</a>.</p>
<p>This group then went to the taxonomic community to survey their views on whether a global species list is needed and how it should be run.</p>
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Read more:
<a href="https://theconversation.com/how-a-scientific-spat-over-how-to-name-species-turned-into-a-big-plus-for-nature-138887">How a scientific spat over how to name species turned into a big plus for nature</a>
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<p>The newly published results show that a large majority (77%) of respondents – which included over 1,100 taxonomists and users of taxonomy across 74 countries – have expressed support for having a single list of all life on Earth.</p>
<p>They also agreed there should be a governance system that supports the list’s creation and maintenance. Just what that governance system would entail is not yet specified. Deciding that will be the next step in the process.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A small grey animal looking like a cross between a kangaroo and a rat" src="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.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">Understanding species taxonomy is crucial for their management. Knowing the taxonomy of marsupials like this bettong helps identify what needs conserving and where.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bettong-australias-smallest-kangaroo-glances-curiously-1658557687">Tyrrannoid/Shutterstock</a></span>
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<h2>Taxonomists propose hypotheses, not facts</h2>
<p>Why is this important? Many may not realise that when a taxonomist names a new species description, they are proposing a scientific hypothesis, not presenting an <a href="https://link.springer.com/book/10.1007/978-3-319-44966-1">objective scientific fact</a>.</p>
<p>Other taxonomists then look at the evidence provided in the description and decide whether they agree. If people making species lists judge that there is agreement about a hypothesis, the new species goes on their list. </p>
<p>Only after a species is listed can it be protected, studied, eradicated, ignored or whatever else governments decide is appropriate. Scientists and conservation advocates also need species to be listed before they can include them in their work. Until listed, the species remains, for all practical purposes, invisible. </p>
<p>However, not all lists are equally trusted. Very rarely taxonomists do go rogue. One notorious taxonomist has been blacklisted for “<a href="https://academic.oup.com/biolinnean/article/133/3/645/6240088?login=falsename">taxonomic vandalism</a>”. He published all sorts of new names – some even commemorated his dog – with little justification. If accepted, his field (herpetology) would have been thrown into chaos.</p>
<p>The work of rogue taxonomists wastes everyone’s time and money. In one instance, poor taxonomy has even killed people – an antivenom labelled with the wrong name for a snake was distributed in Africa and Papua New Guinea <a href="https://pubmed.ncbi.nlm.nih.gov/18359053/">with disastrous results</a>.</p>
<p>Even without rogue taxonomists, there is an enormous problem with so-called synonyms – different people giving different names for the same species. Some species have tens of scientific names, not to mention misspellings. </p>
<p>This leaves users uncertain what name to use. Sometimes they use different names but mean the same species; sometimes the same names but mean different species. The only way to clarify this confusion is by having a working master list of species names linked to the scientific literature.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A colourful coral reef with schools of fish and a turtle swimming above it" src="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.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"></a>
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<span class="caption">Biodiversity is an essential feature of our planet and its ecosystems – but to understand it, we also need to understand the individual species.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tropical-fish-turtle-red-sea-egypt-211006552">Vlad61/Shutterstock</a></span>
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<h2>Now what?</h2>
<p>The newly released survey shows taxonomists and users of taxonomy have achieved an agreement that good lists need good governance. Species lists need to reflect the best science, independent of outside influence. They need dispute resolution processes. And they need involvement and agreement from the taxonomic community on their contents.</p>
<p>Governance of science does not work unless a large majority of scientists agree with the rules, because participation is voluntary. There’s no such thing as science police. </p>
<p>Agreement and compliance is best achieved if scientists themselves are involved in the creation of the rules. This helps to increase buy-in among the community of peers to make sure rules are kept.</p>
<p>Based on the survey results, <a href="https://www.catalogueoflife.org/">the Catalogue of Life</a> – the group that has the most comprehensive global species list to date, and the one we’re involved in – is piloting ways of measuring the quality of the lists that make up their catalogue. </p>
<p>These are being trialled first with the creators of lists, everything from viruses to mammals. Then, they will be tested with the taxonomic community at large for further feedback.</p>
<p>Good taxonomy is far more valuable than people realise. One recent study in Australia found that, for every dollar spent on taxonomy, <a href="https://www.science.org.au/support/analysis/decadal-plans-science/discovering-biodiversity-decadal-plan-taxonomy#report2021">the economy gained A$35</a>. The value of taxonomy globally is likely to be colossal.</p>
<p>But the value will be higher still if everyone the world over is able to use the same list of species.</p>
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Read more:
<a href="https://theconversation.com/scientists-re-counted-australias-extinct-species-and-the-result-is-devastating-127611">Scientists re-counted Australia's extinct species, and the result is devastating</a>
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<img src="https://counter.theconversation.com/content/216006/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Garnett receives funding from the Australian Research Council for a project on taxonomic list governance and coordinates the Catalogue of Life Working Group on Taxonomic Lists. </span></em></p><p class="fine-print"><em><span>Aaron M. Lien is a member of the Catalogue of Life Working Group on Taxonomic Lists and the Global Species List Working Group. </span></em></p>
Only after a species is identified and listed by taxonomists can it be protected. Yet we still don’t have one globally agreed-upon list of every species. A new 74-nation survey points to the solution.
Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University
Aaron M. Lien, Assistant Professor of Ecology, Management and Restoration of Rangelands, University of Arizona
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/154135
2021-01-29T14:25:32Z
2021-01-29T14:25:32Z
Disappearing glaciers are threatening rare alpine plants with extinction
<figure><img src="https://images.theconversation.com/files/381342/original/file-20210129-23-1pzc20.JPG?ixlib=rb-1.1.0&rect=0%2C0%2C4608%2C3069&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Creeping avens – a plant native to mountains in Central Asia and Europe.</span> <span class="attribution"><a class="source" href="https://www.frontiersin.org/articles/10.3389/fevo.2020.616562/full">Losapio/Frontiers in Ecology and Evolution</a></span></figcaption></figure><p>High up on a mountain where winds are too fierce, temperatures too extreme and soils too poor for trees, some of the most unusual plants on Earth grow. In this harsh alpine zone where shade is scarce, species such as the houseleek have evolved to withstand the punishing ultraviolet radiation by being able to <a href="https://www.botanica.ch/cms/dokumente/news/Documentation_Houseleek_V3.pdf">quickly repair their DNA</a>. </p>
<p><a href="https://www.bbc.co.uk/bitesize/guides/zp37hv4/revision/2">Cushion plants</a>, which resemble pin cushions dropped on the ground, grow so close to the soil that they effectively huddle for shelter from the sheer, drying winds overhead. This helps species like vernal sandwort and mossy saxifrage trap dead plant matter blown along the ground – a welcome supply of compost and moisture amid the dry and barren landscape.</p>
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<img alt="A bunch of white and yellow flowers growing close to the rocky mountain soil." src="https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381340/original/file-20210129-19-ok0hn3.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">
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<span class="caption">Mossy saxifrage (<em>saxifraga bryoides</em>) bunches close to the ground to protect itself from howling mountain winds.</span>
<span class="attribution"><a class="source" href="https://www.frontiersin.org/articles/10.3389/fevo.2020.616562/full">Losapio/Frontiers in Ecology and Evolution</a></span>
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<p>These characteristics make some alpine plants very good pioneers – they can arrive on bare ground and begin changing it so that it becomes more suitable for other species. But as the global climate changes, mountain ranges are warming fast. Despite its hardy reputation, the unique flora of these regions faces an uncertain future. </p>
<p>In <a href="https://www.frontiersin.org/articles/10.3389/fevo.2020.616562/full">a new study</a> published in Frontiers in Ecology and Evolution, researchers found that one-fifth of alpine plant species on four glaciers in the Italian Alps are likely to become locally extinct once the glaciers vanish from the high mountains. Some of these European species are plants which are found nowhere else on Earth.</p>
<h2>Why alpine plants need glaciers</h2>
<p>In Valmalenco in the Italian Alps, the Ventina glacier is receding by about <a href="https://www.euronews.com/2017/07/21/from-ice-to-rocks-a-tale-of-glacier-retreat-in-the-italian-alps">30 metres a year</a>. As it retreats, the glacier unveils bare ground which, in many places, has been covered by ice for thousands of years. In the past, glaciers have advanced with cooler temperatures and greater snowfall, and retreated in warmer and less snowy periods. Scientists have long studied the sequence of colonisation of bare ground by plants as time passes from the glacier’s retreat, often over many centuries. </p>
<p>This is a process similar to what many readers will have observed on bare ground prepared for planting in a garden. If the ground is left even for a short period, opportunistic weedy species quickly establish themselves. Left for longer, a whole community of different plants develops. New arrivals grow and shade the early colonisers, stabilise the ground and help trap moisture, changing conditions so that pickier plants can put down roots. </p>
<figure class="align-center ">
<img alt="A patch of buttercups in bare rock with a glacier in the background." src="https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381304/original/file-20210129-17-1ds3c6y.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">
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<span class="caption">Glacier buttercups (<em>Ranunculus glacialis</em>), which are among the highest ascending alpine plants, in front of the Rutor glacier, Italy.</span>
<span class="attribution"><a class="source" href="https://www.frontiersin.org/articles/10.3389/fevo.2020.616562/full">Losapio/Frontiers in Ecology and Evolution</a></span>
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<p>New areas of bare ground in front of retreating glaciers are where many unique alpine plants are adapted to thrive. But with continued warming threatening the extinction of some glaciers, halting the uncovering of new bare ground year upon year, the rare alpine colonisers are forced higher and higher up the mountain and eventually left with nowhere to grow.</p>
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Read more:
<a href="https://theconversation.com/plant-blindness-is-obscuring-the-extinction-crisis-for-non-animal-species-118208">'Plant blindness' is obscuring the extinction crisis for non-animal species</a>
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<h2>‘Escalator to extinction’</h2>
<p>In the constant battle for space, light, water and nutrients, there are inevitably winners and losers. Pioneer species are specialised for doing well in open habitats, but the conditions these specialists help create are exploited by more competitive species which eventually push them out. These generalist competitors are more likely to flourish in the long term as glaciers vanish. They represent 29% of alpine species and include alpine meadow-grass and dwarf yellow cinquefoil.</p>
<figure class="align-center ">
<img alt="A fan-like plant with green and purple flowers." src="https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381347/original/file-20210129-17-1e2ahrs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Alpine meadow-grass (<em>Poa alpina</em>) has a vast distribution throughout the northern hemisphere.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Poa_alpina#/media/File:Alpen-Rispengras_(Poa_alpina).jpg">Heinz Staudacher/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Without glaciers exposing new bare ground, not only are pioneer species lost, but the process they help start is affected. The very warming that is causing glaciers to retreat is also forcing plants from lower altitudes upwards into the alpine zone, adding to the pressure on existing alpine specialists and ultimately favouring fewer, more competitive plants. </p>
<p>What will happen with these new communities of plants is unclear. But plants support a wider community of species, including pollinating insects, grazing animals and soil microbes that stitch together alpine ecosystems. Losing certain plant species and reducing the mountain’s overall biodiversity will have consequences stretching far beyond the plants themselves.</p>
<p>Slowing the rate of global warming would probably slow the rate at which the world’s glaciers are retreating. But for many dependent alpine species, it may already be too late.</p><img src="https://counter.theconversation.com/content/154135/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Baxter receives funding from the Natural Environment Research Council and the Leverhulme Trust.</span></em></p>
Glaciers support a unique community of plants, many of which are found nowhere else.
Robert Baxter, Associate Professor of Plant Ecology, Durham University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/146109
2020-09-29T20:01:34Z
2020-09-29T20:01:34Z
Once again, wattles are out in bloom: here’s what makes our iconic flowers so special
<figure><img src="https://images.theconversation.com/files/359953/original/file-20200925-14-11k2voc.jpg?ixlib=rb-1.1.0&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>Spring has arrived, and all over the country the hills and riversides are burnished with the green and gold of Australian wattles, all belonging to the genus <em>Acacia</em>. </p>
<p>It’s a spectacular sight, but not a surprising one as there are about 1,000 Australian species in the <a href="http://www.anbg.gov.au/acacia/"><em>Acacia</em></a> genus ranging from very small shrubs to tall, longed-lived trees. They occur in ecosystems from the arid inland to the wet forests of the east coast. </p>
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Read more:
<a href="https://theconversation.com/tree-ferns-are-older-than-dinosaurs-and-thats-not-even-the-most-interesting-thing-about-them-138435">Tree ferns are older than dinosaurs. And that's not even the most interesting thing about them</a>
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<hr>
<p>Wattles have been widely used by Indigenous people for millenia, and celebrated by “<a href="http://www.wattleday.asn.au/about-wattles/what-do-you-know-a-few-wattle-facts">Wattle Day</a>” on September 1 for more than a century. </p>
<p>But their lineage may be much older. Australian wattles have relatives in Africa, South America, India and parts of Southeast Asia. This distribution suggests the wattles may have originated in Gondwana before the super-continent fragmented about 180 million years ago. </p>
<p>So let’s take a closer look at what makes these iconic flowers so special. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Wattle on a cloudy day" src="https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/359954/original/file-20200925-20-90ckdc.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">Wattle can always brighten a dreary day.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Don’t blame wattles for your hay fever</h2>
<p>Not everyone welcomes the wattles’ golden blooms — many blame wattle pollen for their hay fever or asthma. </p>
<p>However, many species of wattle have <a href="https://www.abc.net.au/news/health/2015-09-23/dont-blame-the-wattle/6791396">aggregated pollen</a>, which means it’s very heavy and tends to fall straight to ground. You have to be virtually under the plant for it to affect you. </p>
<p>They can cause trouble, but it’s more likely your allergy is due to some other inconspicuous plant, such as grass, that you haven’t noticed compared to the bright yellow of the wattles. It’s worth having an allergy test.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-manage-grass-pollen-exposure-this-hay-fever-season-an-expert-guide-123271">How to manage grass pollen exposure this hay fever season: an expert guide</a>
</strong>
</em>
</p>
<hr>
<p>While a majority of wattles flower in spring and summer, a significant group — such as the sunshine wattle (<em>A. botrycephala</em>), Gawler Range wattle (<em>A. iteaphylla</em>) and flax wattle (<em>A linifolia</em>) — flowers in <a href="https://www.abc.net.au/science/articles/2003/07/03/2578547.htm">autumn and winter</a>. This can give the impression in some places that they’re flowering year-round. </p>
<p>What’s more, many species are hardy, and they can help in the process of taking nitrogen from the air and adding to the soil. That means they can be very handy in ancient, nutrient-poor Australian soils. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A mulga in the Australian desert" src="https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=521&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=521&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=521&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=654&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=654&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360472/original/file-20200929-14-1r2142v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=654&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mulga grows over about 20% of our continent.</span>
<span class="attribution"><span class="source">Mark Marathon/Wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Many of the smaller shrub wattles may live for only a decade or so, but some, <a href="http://theconversation.com/the-mighty-mulga-grows-deep-and-lives-long-118838">such as mulga</a> (<em>Acacia aneura</em>) can live for centuries and are crucial to the viability and stability of arid inland ecosystems. They can have surprisingly large and deep root systems for such small shrubs or trees. This is to obtain water, but also binds the soil.</p>
<p>However, mulga-munching horses, cattle and other feral grazers threaten the persistence of mulga-dominated communities. If mulga and other inland <em>Acacia</em> species are lost, the soils can become loose and mobile, which results in stable productive land becoming desert.</p>
<h2>By any other name</h2>
<p>In the early 2000s, there was <a href="https://www.australiangeographic.com.au/topics/wildlife/2016/03/the-wattle-war/">fierce debate</a> among plant taxonomists about how closely the African and Australian species were related. </p>
<p>The name “Acacia” rightly belonged to the African group, but because there were so many Australian species that would need to be renamed, Australia was allowed to keep the name “Acacia” in 2011 — much to the chagrin of foreign taxonomists. </p>
<p>This resulted in the genus being divided. Australian wattles stayed as <em>Acacia</em>, but African wattles are now in the genera <em>Vachellia</em> or <em>Senegalia</em>, and those from the middle Americas (around Mexico) are <em>Acaciella</em> and <em>Mariosousa</em>. </p>
<p>The different names reflect long, separate histories and different ecological characteristics. (The name changes rankle still with taxonomists!) </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of black wattle flowers" src="https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360467/original/file-20200929-22-65x56c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Black wattle is a pest overseas.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>There are also weedy wattles in Australia and elsewhere. Many of us know from hard experience that the splendid ornamental tree, Cootamundra wattle (<em>Acacia baileyiana</em>), can become a weed if it grows outside its very restricted natural range in New South Wales. And Australia’s <a href="http://theconversation.com/the-black-wattle-is-a-boon-for-Australians-and-a-pest-everywhere-else-100529">black wattle</a> (<em>A. mearnsii</em>) is a significant weed in other parts of the world. </p>
<p>It can come as a bit of a blow to know Australia’s floral emblem, golden wattle (<em>A. pycnantha</em>), can be weedy both at home and when it travels abroad (perhaps like some Australians). </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-black-wattle-is-a-boon-for-australians-and-a-pest-everywhere-else-100529">The black wattle is a boon for Australians (and a pest everywhere else)</a>
</strong>
</em>
</p>
<hr>
<p>Interestingly, most of the Australian wattles lack thorns, unlike <a href="http://worldwidewattle.com/schools/animals.php">their relatives in Africa</a>. In Africa, thorns protect the plants from large mammalian grazers such as giraffes. </p>
<h2>Ants love wattles, too</h2>
<p>If you don’t like ants, it might be worth checking which species of wattle you have in your backyard, or intend to buy.</p>
<p>Many wattles have a very special relationship with some insects. In Central America, ants penetrate the thorns of Bulls Horn wattle trees and establish their colonies. They then defend the tree against other insects, and if branches of another tree touch the host tree, the ants will cause such damage that the other tree will die back. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360464/original/file-20200929-20-dftc3q.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">There are more than 1,000 species of wattle in the <em>Acacia</em> genus.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In Australia, the relationship between ants and wattles is based on food. The hard wattle seeds have a tasty and oil-rich outgrowth called an “aril”, which is irresistible to some ant species. </p>
<p>The ants harvest the seeds and take them back to their nest, where they’re safe from other hungry grazers until it is damaged by fire or flood and the seeds germinate. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-tiny-ants-have-invaded-your-house-and-what-to-do-about-it-132092">Why tiny ants have invaded your house, and what to do about it</a>
</strong>
</em>
</p>
<hr>
<p>Some wattles, the mulga among them, have little <a href="http://worldwidewattle.com/schools/animals.php">glands</a> at the base of their phyllodes (the modified leaf stalks). These glands secrete a form of sugary syrup that attracts feeding ants. These ants may also protect host trees or perhaps leave the flowers alone to allow a greater seed set to grow. </p>
<p>It’s clear wattles have a lot going for them. They are diverse in number, habit, size, longevity and flowering season — there’s a wattle for every occasion. For all of these great traits, it’s still that green and gold that endears them to Australians.</p><img src="https://counter.theconversation.com/content/146109/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>
With their vibrant blooms and a lineage tracing back to the ancient supercontinent of Gondwana, wattles have a lot going for them.
Gregory Moore, Doctor of Botany, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/118757
2019-07-14T12:19:24Z
2019-07-14T12:19:24Z
The human microbiome is a treasure trove waiting to be unlocked
<figure><img src="https://images.theconversation.com/files/282912/original/file-20190705-51278-50p95h.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5851%2C3894&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Understanding the human microbiome will lead to breakthroughs in health care, including treatments for ailments such as irritable bowel syndrome.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Bacteria are at the centre of all life forms on planet earth and are the essential building blocks that make living organisms the way they are. </p>
<p>Both the <a href="http://doi.org/10.1146/annurev.cb.04.110188.001445">mitochondrion</a> — found in most organisms, which generates energy in the cell — and the <a href="https://phys.org/news/2017-08-chloroplast.html">chloroplast</a> — the solar energy-harvester located in plants — can be traced to their bacterial ancestors. These specialized microbes laid the foundation for the biodiversity we live amongst. </p>
<p>Microbes are a part of all multicellular organisms, where they perform a myriad of functions essential to life, including the digestion of nutrients and signalling processes. The microbes that are an integral component of living organisms are referred to as the microbiome. The microbiome is found in creatures <a href="https://theconversation.com/meet-hydra-the-shape-shifting-dr-manhattan-of-the-animal-kingdom-28129">as simple as the hydra</a> and as complex as humans, elephants and trees. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-victorians-help-explain-our-obsession-with-the-microbiome-86270">How the Victorians help explain our obsession with the microbiome</a>
</strong>
</em>
</p>
<hr>
<h2>Human microbiome</h2>
<p>Microbes are part of humans from the initial stage of development and play an important role in the functioning of the human body. The human microbiome is composed of viruses, bacteria and fungi residing in communities within and on the body. </p>
<p>Even though these microbes have always been part of the human anatomy, they were visualized only recently with technological advances like molecular imaging tools and next-generation genetic sequencing. We can now visualize these microbial entities as they operate and execute vital tasks. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=437&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=437&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=437&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=549&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=549&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283759/original/file-20190711-173329-1y8dd1p.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=549&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 microbiome is the largest organ you may have never heard of, weighing up to three kilograms.</span>
<span class="attribution"><span class="source">Human Microbes: The Power within (2018)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The human microbiome is one of the largest organs, weighing approximately two to three kilograms in an adult. Although it is invisible, the microbiome makes its physical presence evident with occasional noises and smells.</p>
<p>The microbiome bestows on us the unique traits we possess. The make-up of the microbiome changes during our life span, and a decrease in the number and diversity of its constituents is associated with diseases and ageing. In fact, healthy individuals and centenarians are known to house a wider diversity of microbial partners than unhealthy individuals.</p>
<h2>Location-specific functions</h2>
<p>The microbiome works in harmony with various organs in the body and aids in the proper functioning of a human being. For example, microbes living on the surface of the skin guard against invasion from opportunistic bacteria and pathogens. These microbes also <a href="https://www.springer.com/gp/book/9789811076831">help in healing wounds, fortifying the immune system and producing volatile signalling molecules essential for communication within the body and the nervous system</a>. </p>
<p>The gut, which harbours the highest amount of microbes, would not be able to carry out its digestive duty without microbial assistance. Microbes in the gut possess a variety of enzymes dedicated to the digestion of complex carbohydrates and the extraction of nutrients from the foods we consume. An average person <a href="https://www.nationalgeographic.com/what-the-world-eats/">consumes up to 60 tonnes of food during his or her lifespan</a>. A digestive tract devoid of microbes would require even more food, a situation the world would prefer to do without. </p>
<p>Intestinal microbes also produce <a href="https://doi.org/10.1038/nature10213">vitamins like B12</a> (pivotal for metabolic activity), hormones, neurotransmitters and a plethora of metabolites integral to normal bodily processes. They also play an active role in the fate of medications we ingest. In fact, drugs taken orally interact with the gut microbiome first before reaching their intended targets. </p>
<p>The molecular entities, like short-chain fatty acids, derived from the microbiome are part of our normal development process. </p>
<p>Microbes are unique to both the individual and the site on the body where they are lodged. For instance, the oily forehead tends to be <a href="https://dx.doi.org/10.1007%2Fs00253-017-8616-7">the preferred residence of Propionibacteria</a> while the <a href="https://doi.org/10.1111/1462-2920.12891">moist nose is populated by Corynebacteria</a>. The <a href="https://doi.org/10.1177%2F2050640614566846">stomach possesses acid-tolerant bacteria</a> while the colon harbours anaerobic dwellers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282911/original/file-20190705-51284-15wtkat.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Image 15/21 from <em>1000 Handshakes</em>, a bioartistic microbiome mapping project.</span>
<span class="attribution"><a class="source" href="https://wellcomecollection.org/works/q28cguue">François-Joseph Lapointe, Université de Montréal</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Understanding the microbiome</h2>
<p>This invisible organ is modulated by disparate factors including parental genetics, geography, food and lifestyle. Although microbiome finger-printing is in its infancy, it is clear that an individual living in an urban area will house a different microbial community relative to a rural inhabitant. As the microbiome is like any other organ, the disruption of its cellular components — <a href="https://doi.org/10.1080/16512235.2019.1567968">known as dysbiosis</a> — can trigger a range of ailments like obesity, irritable bowel syndrome, dermatitis and neurological imbalance. Some of these diseases can be cured by the use of probiotics and prebiotics designed to adjust microbial imbalance.</p>
<p>Although this expansive invisible organ was <a href="https://doi.org/10.1038/nature06244">visualized only recently</a>, the unravelling of its functions, coupled with the understanding of its origins, could lead to major changes in health care, health education, nutrition and personal traits. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=910&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=910&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=910&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1143&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1143&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283758/original/file-20190711-173329-1e0omlb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1143&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Understanding the human microbiome and the role it plays in health and well-being will revolutionize our approach to our bodies and their care.</span>
<span class="attribution"><a class="source" href="https://www.springer.com/gp/book/9789811076831">Springer</a></span>
</figcaption>
</figure>
<p>The identification of each microbial constituent and its role will enable the classification of each individual according to his or her microbe type; this has the potential to be as revolutionary as the discovery of blood groups in the twentieth century. Microbial fingerprinting would result in a seismic shift in health quality and delivery. </p>
<p>Manipulation and enrichment of select microbial communities — referred to as microbiome engineering - would improve health, rejuvenate organs, enhance character traits and <a href="https://doi.org/10.3390/fermentation5020041">lead to more effective medications</a>. </p>
<p>Microbe-supplemented creams for skin diseases and microbe-fortified nutritional supplements are already being routinely touted as personalized cures. The tracking of microbes and their metabolites may become a common molecular strategy to <a href="http://doi.org/10.1038/d41586-018-07432-8">identify individuals</a> and even <a href="https://dx.doi.org/10.1016%2Fj.jcmgh.2018.04.003">their behaviours</a>.</p>
<p>We are just at the dawn of a health revolution that has the potential to be a societal-game changer.</p><img src="https://counter.theconversation.com/content/118757/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:vappanna@laurentian.ca">vappanna@laurentian.ca</a> receives funding Northern Ontario Heritage Fund . Professor of Biochemistry, Laurentian University, Sudbury, Ontario, Canada</span></em></p>
The microbiome is one of the largest organs in the body. Understanding its constituents and their functions will lead to breakthroughs in health care and well-being practices.
Vasu Appanna, Professor, Biochemistry, Laurentian University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/111914
2019-05-09T00:15:18Z
2019-05-09T00:15:18Z
Curious Kids: why do leaves fall off trees?
<figure><img src="https://images.theconversation.com/files/261803/original/file-20190304-110130-10nw2vb.jpg?ixlib=rb-1.1.0&rect=11%2C11%2C3982%2C1976&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The short answer is that leaves fall off trees when they aren’t doing their job any more. </span> <span class="attribution"><span class="source">Emily Nunell/The Conversation CC-NY-BD</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Why do leaves fall off trees? - Emma, age 5.</strong></p>
</blockquote>
<hr>
<p>Great question! The short answer is that leaves fall off trees when they aren’t doing their job any more. </p>
<p><a href="https://theconversation.com/curious-kids-how-can-a-tiny-seed-actually-grow-into-a-huge-tree-77873">A leaf’s job is to turn sunlight into food for the tree.</a> To do this, the leaf needs water. This water comes from the soil, and is sucked up through pipes in the trunk and branches all the way to the leaves – this can be a very long way for tall trees! </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=529&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=529&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=529&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=665&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=665&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272689/original/file-20190506-103068-1okr59a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=665&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’s a very long way from the ground all the way up to the leaves of these gum trees!</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/162037208@N08/45580284612/in/photolist-2crLSC5-HyeKhe-23w2dzP-pifcYt-dse1bm-qLMUKJ-oUSbKw-23vC8kh-R8A3Gt-oQ8A8L-8hBVxh-Uhm1Gz-kxAEZ2-59yR75-dHiLKp-4JDBMb-qyMLp8-FsoViq-9ov8Bc-ZdVaTP-pWPvML-p4dgra-22oteSy-anpnUd-o9qZJd-25K45jb-27ozfHC-osFtLp-axyzSg-298XEvQ-G6Rn2-2dWVkU4-TVHMf-o9qZPp-Yk3v7z-7rAYyL-5aDMTJ-4kJnUT-nTW8Bg-w5bgvZ-hxM7ha-kxDuFu-vtuRLX-kvGJiK-oLHnzk-5hi4mV-x23Fnq-ZHCAdb-88LGvC-9kRr3r">Flickr/Geoexplore</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>If there isn’t enough water, the leaf can be damaged and stop working. The tree doesn’t want to waste all the good things in the leaf, so it takes the nutrients from the leaf back into the stems and roots. This way, they can be recycled. </p>
<p>When the leaf is empty, the tree stops holding onto it and it falls to the ground, or blows away in a gust of wind. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-can-a-tiny-seed-actually-grow-into-a-huge-tree-77873">Curious Kids: how can a tiny seed actually grow into a huge tree?</a>
</strong>
</em>
</p>
<hr>
<h2>What are deciduous trees?</h2>
<p>Some trees lose their leaves every year. These trees are called deciduous trees, and they lose their leaves in response to the seasons. Deciduous trees mostly come from places where winter gets cold and snowy. </p>
<p>When it is very cold, the water in the tree can freeze – the leaves stop working and can even be damaged by the ice crystals. These trees know to prepare for this, and start taking nutrients out of the leaves when the days get shorter in autumn – <a href="https://theconversation.com/curious-kids-why-do-leaves-change-colour-105318">this is when we can see them changing colour.</a></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272688/original/file-20190506-103075-1gdgh93.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">It makes sense for trees to lose their leaves before winter in places where it gets very snowy.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dainec/5310764907/in/photolist-96i4oc-22BycxZ-23sckN2-94f223-Rny5Wm-SqomyL-93puxu-2dYQDXc-2a9U7bu-FbXgtm-qHHYs6-2ecnv9g-KgJNtT-2dDV4kS-21WbqzJ-2441YzE-9gT7rF-97nSLz-dCzUTx-aqXmf-RZCtg3-Jmzrq4-94EZBY-7pGzde-QNbR86-imRXK8-25rCUa4-dSM29r-XCC2sL-H8qmvF-R6p8dr-2esj77m-2dMByib-22vPVnT-pZT8cX-ZQZ2BK-2dQrmDx-2doEZET-RSYJVB-2cDov3W-CLaCfr-2eW18Xc-qfHJ9X-dQ1EHr-22iVh1u-92S7TK-JYZfkM-r5ATsy-ScXZHk-TBiGGe">Flickr/Aine</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But there are deciduous trees in tropical places where it never gets cold. Winter in these places is very dry. When the rainy season ends, the tree knows that it will not have very much water for a few months, so it lets go of its leaves. </p>
<h2>Trees hibernate too</h2>
<p>When the tree is leafless, it can’t make food. But it doesn’t get hungry. Instead, it rests. </p>
<p>Just like a bear goes into hibernation and snoozes all through winter, trees have a long sleep until the water in the pipes starts moving again. This can be in spring, or when it starts to rain again. Then, they wake up and put out new leaves, so they can start making food again. </p>
<p>Some trees hold onto their leaves all year long. These trees are called evergreens, because they stay “ever green”. But the leaves on these trees all die and fall off eventually. That happens when the leaves are old or damaged. Leaves don’t work very well after they’ve been munched on by an animal.</p>
<p>Leaves are really important for the tree, but sometimes it’s better for the tree to let them go. They can save all the good bits and when there is enough water, they can use them to grow brand new leaves.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-where-did-trees-come-from-92518">Curious Kids: Where did trees come from?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/111914/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matilda Brown 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>
Leaves fall off trees when they aren’t doing their job any more. If there isn’t enough water, the leaf can be damaged and stop working.
Matilda Brown, PhD, University of Tasmania
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/114731
2019-04-08T01:07:26Z
2019-04-08T01:07:26Z
The swamp foxtail’s origin is hidden in its DNA
<figure><img src="https://images.theconversation.com/files/267731/original/file-20190405-123431-tb8724.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Swamp foxtail is prized in ornamental gardens across Australia.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/31031835@N08/8667567151/">John Tann/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>Sign up to the Beating Around the Bush newsletter <a href="https://theconversation.com/au/newsletters">here</a>, and suggest a plant we should cover at batb@theconversation.edu.au.</em></p>
<hr>
<p>Swamp foxtail (<em>Cenchrus purpurascens</em>) is a delightful grass that forms a neat tussock up to a metre tall with a distinctive fluffy spikelet that resembles a fox’s tail.</p>
<p>Foxtails are widely used in horticulture. The purple forms are particularly popular in ornamental gardens and some have even become invasive weeds. </p>
<p>The foxtail grasses are more commonly seen in these cultivated settings, which has led to much confusion about swamp foxtails’ origins in Australia. The species is simultaneously an exotic weed from Asia, the dominant grass in an endangered Australian ecosystem and a rare native species in isolated desert springs.</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=802&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=802&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=802&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1008&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1008&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267760/original/file-20190405-180023-pgimq5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1008&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"><span class="source">The Conversation</span></span>
</figcaption>
</figure>
<hr>
<h2>Is it native?</h2>
<p>It was uncertain for a while whether swamp foxtail is actually native to Australia. Although Europeans collected it near Sydney, it was possible the seeds had come with livestock on the early ships.</p>
<p>This theory was put to rest by <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ddi.12751">genetic studies</a> that found small populations have existed in inland Queensland for hundreds of thousands of years. </p>
<p>The species spread southward and was first recorded in Victoria in the 1970s. </p>
<h2>European records</h2>
<p>Robert Brown, the botanist who accompanied Matthew Flinders as he <a href="http://www.publish.csiro.au/BT/BT18168">circumnavigated the continent</a>, made the the earliest European collections of the swamp foxtail near Sydney in 1802. </p>
<p>Despite the early date of the collections, it is feasible that the swamp foxtail was brought to Sydney within 14 years of settlement as a byproduct among grain or hay. However, while the species occurs naturally in Asia, the Javanese ports were not on the typical travelling route from Europe.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/spinifex-grass-would-like-us-to-stop-putting-out-bushfires-please-105651">Spinifex grass would like us to stop putting out bushfires, please</a>
</strong>
</em>
</p>
<hr>
<p>The intrepid adventurer Ludwig Leichardt later collected this species near the Gwydir River region. This collection provides more convincing evidence the swamp foxtail is <a href="http://www.publish.csiro.au/BT/BT18168">native to Australia</a>. It seems unlikely that, in the early years of colonisation, the swamp foxtail had been transported overland with the squatters who were spreading out from their successful properties in the Hunter Valley.</p>
<h2>The spread southward</h2>
<p>The history of herbarium records, from collections in the late 1800s and early 1900s, suggests swamp foxtail might have been native to Queensland and New South Wales. </p>
<p>Collections south of these locations happened after 1940. The species was not recorded in Victoria until the 1970s. It seems almost certain the swamp foxtail spread southward during the 20th century, in some places as an undesirable weed.</p>
<h2>Unusual and isolated habitats</h2>
<p><a href="https://www.tandfonline.com/doi/abs/10.1080/00049180120100040">Aboriginal fire management</a> possibly maintained natural grassy openings among the northern NSW rainforests. The curious “grasses”, as they were named, are well documented on early survey plans of the Big Scrub country. Many a place name, Howards Grass Road and Lagoon Grass Road among them, bear testament to their existence.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/268021/original/file-20190408-2898-1soxym9.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">An extremely isolated population of the swamp foxtail at Elizabeth Springs in western Queensland.</span>
<span class="attribution"><span class="source">Rod Fensham</span></span>
</figcaption>
</figure>
<p>The surveyors provided detailed recordings of the dominant grass on the valley floors: the “foxtail”. The swamp foxtail is now rather rare on the valley floors of the Richmond and the Tweed River valleys, replaced by crops on prime agricultural land. It managed to survive in a few locations west of Murwillumbah and on springs, but large expanses of the foxtail grasslands have succumbed to the plough.</p>
<p>A particularly unusual habitat for the swamp foxtail is the artesian springs that feed permanent wetlands in the semi-deserts of inland Queensland. The swamp foxtail occurs there in very local populations <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ddi.12757">separated by hundreds of kilometres</a>. </p>
<p>This raises the question: is the swamp foxtail a recent arrival on these tiny, strange and isolated ecosystems, or are these ancient populations? </p>
<p>Genetic studies have provided conclusive evidence of an ancient origin. The oldest lineage is the population at Elizabeth Springs to the south of Boulia. Its molecular signature suggests this population has been <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ddi.12751">isolated for hundreds of thousands of years</a>. </p>
<p>Where swamp foxtail does occur at springs, it is always accompanied by rare species that are seen only in those unusual wetlands.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/grass-trees-arent-a-grass-and-theyre-not-trees-100531">Grass trees aren't a grass (and they're not trees)</a>
</strong>
</em>
</p>
<hr>
<h2>Crossing continents and climates</h2>
<p>Swamp foxtail demonstrates the complexity of defining a species’ origin. This species probably evolved in Asia, because this is where most of its relatives are found. It found its way to Australia, possibly through a migratory bird that dropped a seed in a desert spring. </p>
<p>It then had a second migration, either from the springs or from a repeat dispersal from Asia, and found a niche in the valley floors of subtropical landscapes. It was abundant in these moist and fertile habitats when Europeans colonised the continent in 1788. </p>
<p>Since then, the swamp foxtail has spread to temperate climates where it has become invasive and, in some situations, <a href="http://www.aabr.org.au/images/stories/resources/ManagementGuides/WeedGuides/wmg_pennisetum.pdf">a minor pest</a>. Quite a journey.</p><img src="https://counter.theconversation.com/content/114731/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roderick John Fensham 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>
Present in Asia and Australia, the origins of swamp foxtails have not always been clear. Genetic studies put uncertainties to rest.
Roderick John Fensham, Associate Professor of Biological Sciences, The University of Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/110797
2019-03-11T01:56:03Z
2019-03-11T01:56:03Z
Curious Kids: what happens when fruit gets ripe?
<figure><img src="https://images.theconversation.com/files/258913/original/file-20190214-181599-18k7nwq.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2048%2C1281&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">These strawberries are almost ripe!</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/fs999/35874015121/in/photolist-89s9dN-WL9ujy-6wpRXc-ck6kGh-cyQinL-Fah6iz-eK4YbK-bgae5T-cFWDJm-MFXfac-cyQiuG-4MMfGY-eK4riB-51Hb7w-btRhQ6-6obGoj-WE4GS6-6wmnAV-uaYN-6yvBP2-6yzJhf-6yzJd9-utxGRN-66Tg74-6yvBKg-9WEDFs-H3NThw-4WX6n5-9HbM5E-66XHNq-6WJoDk-5yTMch-23vkLP1-7SsfLm">fs999/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>What happens when fruit gets ripe? - Rachel, age 3, Melbourne.</strong></p>
</blockquote>
<hr>
<p>Hi Rachel. You have asked a very interesting question.</p>
<p>Fruit ripening is all about plants getting animals to eat the seeds that are inside their fruits. </p>
<p>When the animals have finished eating, they move around and drop the seeds in a different place when they do a poo. This helps the plants get their seeds to somewhere new where they can grow into a new plant. </p>
<h2>A fruit wants to be eaten but only when the time is right</h2>
<p>But plants need to make sure that their fruits are only eaten when their seeds are ready to be spread around. </p>
<p>So before the seeds are ready, the plants make sure that the fruit are not easy to see and are horrible to eat. This means the fruits may stay green and may stay hidden among the leaves, so it’s harder to pick them. They are also very hard and bitter to taste, so animals (including humans) don’t like eating them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258966/original/file-20190214-1751-joj97b.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>
<figcaption>
<span class="caption">Did you know that tomatoes are fruit? This is what they look like when ripening at each stage.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/evolution-red-tomato-maturing-process-fruit-252024166?src=P1WEblyQ30s4dcQyefUnEA-1-6">Alena Brozova/shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-tongues-taste-food-103744">Curious Kids: how do tongues taste food?</a>
</strong>
</em>
</p>
<hr>
<p>When the seeds are ready, the fruit become ripe and good-looking, making animals keen to eat them. </p>
<p>When the fruit are ripe they become brightly coloured. Apples, strawberries and peaches become red, bananas become yellow and, of course, oranges become orange. </p>
<p>Next time you go the supermarket, look at the beautiful colours of the fruit in there and see how many different colours you can find. </p>
<h2>Softer, sweeter and nicer to smell</h2>
<p>At the same time as fruit change colour, they also become soft. This is because fruit are made from many tiny things called cells. </p>
<p>In plants, each cell has a wall. There is stuff in the cells’ walls that changes to make the fruit soft, and it is this softening that makes them juicy.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258931/original/file-20190214-1754-1e1kglh.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">Each of these boxes is a cell in an onion. And each cell is separated by a cell wall.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/uafcde/2233758/in/photolist-WJvWNW-cs25-f93smE-XkKS1M-X3wJBT-cyD7fC-5UYHZp-W4Ps9o-6jGTHg-XC1r1v-dvfi6d-Xpmqsv-Xy5tRs-XnkFp9-XwA8fu-WjSvoo-f93scL-6YCpcH-dvYaph-9y4Pff-93A6yb-dvSF4a-6QJbQ8-8nLvJ2-UnsRBq-WjSv6E-WJKA1L-XBtQ8e-WJvXYG-W7jG5D-XkKNse-Wne2ae-X8JMbB-WjSw39">UAF Center for Distance Education/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>I bet the thing you most like about fruit is that they are sweet and yummy to eat. When the fruits ripen, the plant cleverly removes all of the bad-tasting stuff from the fruit and replaces them with sugars. That, of course, makes the fruit sweet and nice to eat. </p>
<p>The last thing that changes when fruit ripen is that they make stuff that helps them smell really nice, which makes animals and people want to eat them. </p>
<p>Different fruits have different stuff in them that makes them smell the way they do. That is why we can tell a pear from a strawberry, just by smell alone.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-spiders-have-hairy-legs-108602">Curious Kids: why do spiders have hairy legs?</a>
</strong>
</em>
</p>
<hr>
<h2>A tricky gas called ethylene</h2>
<p>These changes that happen when fruit ripen (the change in colour, smell, sweetness and softness) all happen at the same time. </p>
<p>To make this happen, many fruit use another special thing called ethylene. This ethylene is helpful. </p>
<p>The bananas you eat come from farms in Queensland. They are picked when they are green and a bit hard. They are picked before they are ripe so they don’t get damaged while they are being taken to shops near your house in Melbourne. </p>
<p>When they arrive in Melbourne, the people in charge of those green bananas will put some ethylene gas near them to ripen them up. Then they are put in shops so we can buy them when they are yellow and ripe to eat. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258964/original/file-20190214-1721-188c871.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">You can see the difference between unripe bananas (left) and ripe bananas (right)</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/green-unripe-yellow-ripe-mature-bananas-1060060118?src=IPVc02S_BmmWpq_boEO4dw-1-68">cryptographer/shutterstock</a></span>
</figcaption>
</figure>
<p>The most important thing about all fruits is that they are very good for us. </p>
<p>The sugars inside them are a great way to get energy that helps us work and play all day. </p>
<p>They are also full of vitamins that help us become big and strong. So it’s important that we eat lots of fruit. But don’t forget your veggies, as they are also very good for us!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-do-butterflies-remember-being-caterpillars-99508">Curious Kids: Do butterflies remember being caterpillars?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/110797/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Holford has received funding from the Horticultural Research and Development Corporation, Woolworths Ltd. and the Agricultural Company of Australia Pty Ltd. and Horticulture Australia Ltd. for work on postharvest technology.</span></em></p>
Fruit ripening is all about plants getting animals to eat the seeds that are inside their fruits. This helps the plants get their seeds to somewhere new where they can grow into a new plant.
Paul Holford, Professor of Agricultural Biotechnology, Western Sydney University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/108760
2018-12-14T02:26:32Z
2018-12-14T02:26:32Z
Native cherries are a bit mysterious, and possibly inside-out
<figure><img src="https://images.theconversation.com/files/250594/original/file-20181214-178555-acj9vb.png?ixlib=rb-1.1.0&rect=0%2C0%2C2824%2C1495&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/31031835@N08/6700452189/in/photolist-b3n3ak-oadgke-bd6yZK-5ukQUw-5ukQzj-bdVG2D-CrySWD-bd6GrR-eTrind-NvSsv1-r8A7An-BBkJJ3">John Tann/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>People don’t like parasites. But there’s a local Aussie tree that’s only a <em>little bit</em> parasitic: the native cherry, or cherry ballart.</p>
<p>It’s what we call <em>hemiparasitic</em>. It can photosynthesise, but gains extra nutrients by attaching its roots to host plants. </p>
<p>The native cherry, <em>Exocarpos cupressiformis</em>, might be our most widespread root hemiparasite tree, but we’re not quite sure – root-parasitic shrubs and trees are a bit of a research blank spot. We are not even really sure who all the hosts of cherry ballart are.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/warty-hammer-orchids-are-sexual-deceivers-107805">Warty hammer orchids are sexual deceivers</a>
</strong>
</em>
</p>
<hr>
<p>Although other parasites – like mistletoes – have a more direct Christmas association, cherry ballart does have an Australian Yuletide connection: their conifer-like appearance (the species name <em>cupressiformis</em> means “cypress-like”) was noted by homesick European settlers, who chopped them down for Christmas trees.</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=802&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=802&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=802&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1008&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1008&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250593/original/file-20181214-178555-borqx1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1008&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"><span class="source">The Conversation</span></span>
</figcaption>
</figure>
<hr>
<h2>On the map</h2>
<p>Cherry ballart grows from the Atherton Tablelands in Queensland to southern Tasmania, and across to the Eyre Peninsula in South Australia. </p>
<p>The first European to record it was Jacques-Julien Houtou de Labillardière, the botanist on <a href="https://en.wikipedia.org/wiki/Bruni_d%27Entrecasteaux">d'Entrecasteaux</a>’s expedition in search of La Perouse. He formally described the species in 1800, but we have no physical type specimen – the botanical type is his <a href="https://archive.org/details/voyageinsearchof01labi/page/n5">illustration and description</a>. Maybe he lost his specimen, or disposed of it, or thought a picture would do; Jacques seems to have been a bit <a href="https://www.jstor.org/stable/pdf/1218341.pdf">cavalier with his record-keeping</a>. </p>
<p>Or perhaps it was stolen or misplaced after all his specimens were seized in an overlapping series of defections, wars, defeats and revolution as the expedition tried to return to Europe. The collection was eventually returned after the intercession of English botanist Joseph Banks – but no cherry ballart.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1099&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1099&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1099&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1381&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1381&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250417/original/file-20181213-178582-cedgd1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1381&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Jacques-Julien Houtou de Labillardière’s description of the native cherry.</span>
<span class="attribution"><span class="source">Voyage in search of La Pérouse</span></span>
</figcaption>
</figure>
<p>Its distinctive shape led to native cherry being marked on early Australian orienteering maps, since they are in a cartographic Goldilocks zone: obvious, just numerous enough to make them useful, but not so many as to clutter the map.</p>
<p>That was until Australia held the World Orienteering Championships in the mid-1980s, when the standardisation of Australian orienteering maps for overseas competitors led to the cherry ballart becoming an early victim of internationalisation – at least cartographically speaking. </p>
<p>Its utility also extended to the timber. Among the uses of its “close-grained and handsome wood” are tool handles, gun stocks and map rollers (although the last is probably a niche market these days).</p>
<p>Indigenous Australians ate the fruit, used the wood for spear throwers and reportedly used the sap as a treatment for <a href="https://www.anbg.gov.au/aborig.s.e.aust/exocarpus-cupressiformis.html">snakebite</a>. They <a href="https://naturalingredient.org/wp/wp-content/uploads/usefulnativeplan1889maid.pdf">called</a> it Tchimmi-dillen (Queensland), Palatt or Ballot (Lake Condah, Victoria) and Ballee (Yarra).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/leek-orchids-are-beautiful-endangered-and-we-have-no-idea-how-to-grow-them-103224">Leek orchids are beautiful, endangered and we have no idea how to grow them</a>
</strong>
</em>
</p>
<hr>
<h2>Grow baby, grow!</h2>
<p>Despite producing large quantities of fruit and seed, no one seems to be able to get native cherry to germinate reliably. There are anecdotal reports that feeding the seed to chooks works, but other growers dismiss this approach.</p>
<p>The edible fruit isn’t actually a true fruit: it’s a swollen stem. It’s reported to have the <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1442-9993.1991.tb01476.x">highest sugar level</a> of any native fruit in the forests of southern Victoria and is much tastier than you’d think a stem would be. (It’s also probably an important nutrient supply for some birds, but that’s yet another thing we are yet to prove.) </p>
<p>This odd “fruit” gives rise to the genus name (<em>exo</em> = outside, <em>carpos</em> = fruit,) and was often touted by early European writers as another example of the topsy-turvy nature of Australia – “cherries” with the pit on the outside went along with “duck-billed playtpus”, animals with pouches, trees that shed bark rather than leaves, and Christmas in the middle of summer.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250597/original/file-20181214-178570-1atyxiq.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">The sweet and delicious fruit of native cherries is actually a swollen stem.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/arthur_chapman/3047686708/in/photolist-5Djc5y-8Swtb6-fmna5-djpmLd-5r4Zpn-djpno4-c9ob3E-Ge7EC-doWyVo-4EJQ7b-cEVdbS-5VdvPr-s8ATsU-977N9j-63xqKQ-4DXQiq-JBycJ8-nUCSv8-eigah6-8DCm7j-pGzbmt-6yPwRP-8DCmsA-9oveuP-9ovdhx-4VctFa-pripqq-Uq8c5n-axyzSg-6bTupc-5Vbsw4-HKHN6-bFc6du-jBNVSQ-HKD8u-8BjGsy-5zqXfm-cFnUzj-4VguH1-4VgCHN-4VcyNT-adwMvF-69Ru9e-27b3Cyj-akcwk4-28gtURt-26TRwt2-4EEzJD-bNxMmx-PLvhx">Arthur Chapman/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Despite their oddness, native cherries in the bush are biodiversity hotspots. My camera trap data show they preferentially attract echidnas, possums, foxes, swamp wallabies, white-winged choughs and bronzewing pigeons.</p>
<p>This might be because they modify their immediate environment. My research shows they create moderate micro-climates in their foliage, reduce soil temperatures, increase soil water retention, concentrate nutrients in the soil beneath their canopies, and alter the understorey vegetation. They also kill some of their host trees, creating patches with higher concentrations of dead timber. All these probably have something to do with their animal attraction, but exactly how is a mystery yet to be solved.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-worst-kind-of-pain-you-can-imagine-what-its-like-to-be-stung-by-a-stinging-tree-103220">'The worst kind of pain you can imagine' – what it's like to be stung by a stinging tree</a>
</strong>
</em>
</p>
<hr>
<p>In addition to their attractiveness to vertebrates, native cherries are required hosts for some striking <a href="http://lepidoptera.butterflyhouse.com.au/xylo/porphyrinella.html">moths</a> and share specialist host duties with mistletoe for some of our most beautiful <a href="http://sabutterflies.org.au/pier/aganippe.html">butterflies</a> (although mistletoes take most of the glory in the scientific literature).</p>
<p>My research into our cherry ballart hopes in part to correct these historical slights. I want to set the record straight on this overlooked widespread and attractive little tree, which has a long indigenous use and was one of the first of our native flora to be described by Europeans.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=199&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=199&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=199&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=251&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=251&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=251&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://confirmsubscription.com/h/r/9AE707FA51C4AC1B">Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.</a></em></p><img src="https://counter.theconversation.com/content/108760/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregg Müller 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>
Native cherries are everywhere, but we know surprisingly little about them.
Gregg Müller, Lecturer in Natural History, La Trobe University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/104786
2018-11-06T13:29:29Z
2018-11-06T13:29:29Z
How the colonial past of botanical gardens can be put to good use
<figure><img src="https://images.theconversation.com/files/241600/original/file-20181022-105767-1vzyy1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Kirstenbosch Botanical Garden in Cape Town, South Africa.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Botanical gardens play an important role in shaping national attitudes and encouraging better human <a href="https://www2.le.ac.uk/departments/museumstudies/rcmg/projects/redefining-the-role-of-botanic-gardens/Redefining%20the%20Social%20Role%20of%20Botanic%20Gardens.pdf">connectedness to nature</a>.</p>
<p>They offer <a href="https://academic.oup.com/bioscience/article/61/10/743/258036/The-Evolving-Role-of-Botanical-GardensHedges">education and research opportunities</a> that are critical to plant conservation. Visiting a garden can <a href="http://horttech.ashspublications.org/content/12/3/489.full.pdf">relieve stress</a> and help give people a sense of <a href="https://www.westernsydney.edu.au/__data/assets/pdf_file/0012/884559/LOVE_YOUR_LAGOONS-Place-based_learning_and_environmental_action_in_south_western_Sydney_FINAL_REPORT.pdf">place</a> that extends to the wider region.</p>
<p>Scholars from a variety of disciplines have been working to understand the <a href="https://www.bgci.org/resources/history/">histories</a>, <a href="http://soac.fbe.unsw.edu.au/2011/papers/SOAC2011_0027_final(1).pdf">impact</a> and meanings of gardens to improve conservation outcomes and to build strong communities. </p>
<p>By learning about successful gardening initiatives, these insights can be applied to regions lagging behind in terms of developing and using botanic gardens. Historical research shows that conservation initiatives led by botanic gardens can <a href="http://link.springer.com/article/10.1007/s10530-013-0601-1">spread to other regions</a>, leading to positive outcomes. </p>
<p>There’s an uneven distribution in the world’s botanic gardens – an imbalance based on the legacies of European empire. And a significant amount of research has focused on gardens in former British colonies. These include the “who’s who” of botanic gardens: Kew Gardens in London, Kirstenbosch in Cape Town, Singapore Botanic Gardens, Royal Sydney Botanical Garden, to name a few.</p>
<p>Botanic gardens have changed considerably from their colonial origins. Back then most focused on economic botany and growing attractive plants. Only a few gardens, such as Kirstenbosch, focused on native vegetation. </p>
<p>A global change began in South Africa and Australia in the 1960s. Governments in both countries created indigenous gardens in response to end of <a href="https://www.cambridge.org/core/journals/itinerario/article/decolonization-environmentalism-and-nationalism-in-australia-and-south-africa/F70CF21D129C6AFF91800EF9E37FA5CA">British influence and the rise of environmentalism</a>. These gardens paved the way for new national identities while creating greater appreciation of the floral diversity of each country. </p>
<p>The indigenous gardens also encouraged people to engage in indigenous knowledge and cultures. Indigenous gardening trends in both South Africa and Australia paved the way for other countries. </p>
<h2>Colonial history</h2>
<p>The founders of colonial gardens believed in a philosophy I define as “<a href="http://www.tandfonline.com/doi/abs/10.1080/02582473.2015.1019358?journalCode=rshj20">ecological liberalism</a>” because its liberal values focus on the free movement of people as well as plants. Settlers believed it was acceptable to import species into a new country so long as they did not become overly <a href="http://www.tandfonline.com/doi/abs/10.1080/713683604?journalCode=cjss20">noxious</a> to farmers trying to <a href="http://www.brokenpromisebook.com">recreate European agriculture</a>.</p>
<p>A major shift in attitudes happened in the 1960s and 1970s. Gardens created since the mid-1960s tended to highlight local indigenous species found locally or in the region and, or native flora found in the country. </p>
<p>South Africa and Australia helped inspire global change. In the 1960s, South Africa created a national system of indigenous botanic gardens. In 1965, Western Australia created Australia’s most significant regional indigenous botanic garden in Perth, and the Canberra Botanic Gardens, a native garden, opened in 1967.</p>
<p>Why did Australia and South African residents embrace gardens during this period?</p>
<p>Scientists believe that these gardens were created to highlight the floral diversity of these regions. This is true to a point, but this view was held by a relatively small number of botanical enthusiasts. We must remember that as late as the 1960s, the Western Australian government supported a <a href="http://insidestory.org.au/how-to-eat-a-wilderness">massive expansion of wheat farms</a> in the most diverse floral region of Australia.</p>
<p>Most historians have focused on environmentalism and nationalism as the main causes for the growing celebration of plants.</p>
<p>While each of these viewpoints is partly accurate, they do not make sense unless we recognise that human valuation of nature also changed because of the era of <a href="https://www.cambridge.org/core/journals/itinerario/article/decolonization-environmentalism-and-nationalism-in-australia-and-south-africa/F70CF21D129C6AFF91800EF9E37FA5CA">decolonisation</a>.</p>
<h2>Breaking away from Britain</h2>
<p>South Africa’s decision to leave the Commonwealth in 1961 because of its apartheid policies, and <a href="https://www.mup.com.au/items/9780522865875">Australia’s “abandonment”</a> by Britain in the mid-1960s to early 1970s created a profound <a href="https://www.mup.com.au/items/9780522856453">political and identity vacuum</a>. A generation went from having dual loyalty to Britain and their home country to holding distinctly national identities. </p>
<p>This affected how people, particularly those of British ancestry, related to plants. Instead of celebrating exotics, Australian and South Africans became more passionately attached to indigenous and native plants. </p>
<p>To encourage stronger national and regional identity, government gardens pioneered the growing of indigenous plants. Local plants were bred and studied. When droughts hit in <a href="http://epress.lib.uts.edu.au/journals/index.php/TfC/article/view/1577">Western Australia in the late 1970s</a> and in the Cape in South Africa early 1980s, people could buy seed and plants from these gardens. </p>
<p>A growing awareness of ecology opened the door for white migrants in Australia to recognise the <a href="https://fireecologyjournal.org/docs/Journal/pdf/Volume08/Issue03/jones-169.pdf">knowledge of indigenous peoples</a> who acted as environmental stewards. Today, gardens emphasise <a href="https://www.rbgsyd.nsw.gov.au/visit/history-and-facts/indigenous-heritage">indigenous knowledge and heritage</a>. </p>
<p>The ending of apartheid in 1994 finally allowed for South Africa’s botanical gardens to be racially decolonised. The South African National Biodiversity Institute, which runs <a href="http://biodiversityadvisor.sanbi.org/wp-content/uploads/2016/04/BioSeries_27_2015.pdf">national gardens</a>, now plays a key role in transformation. </p>
<p>Botanical gardens not only help to preserve nature, they also help to build strong, healthy communities.</p><img src="https://counter.theconversation.com/content/104786/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett M Bennett received funding from the Australian Research Council Discovery Grant for the project, 'The Crisis in International Heritage Conservation in an Age of Shifting Global Power' (2014-2016)</span></em></p>
The colonial history of botanical gardens encouraged pride in indigenous flora and culture.
Brett M Bennett, Associate Professor of History, University of Johannesburg
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/100528
2018-11-02T06:09:20Z
2018-11-02T06:09:20Z
Stringybark is tough as boots (and gave us the word ‘Eucalyptus’)
<figure><img src="https://images.theconversation.com/files/243597/original/file-20181102-83635-tlxm2d.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Eucalyptus obliqua as seen in Merthyr Park, Tasmania. </span> <span class="attribution"><span class="source">Cowirrie/Flickr, CC BY-SA</span></span></figcaption></figure><p>Few eucalypts are as versatile, varied and valuable as messmate stringybark. It was the first eucalypt to be scientifically named, and in fact gives us the name “Eucalyptus”. </p>
<p>Gum trees had been seen and collected on earlier expeditions, but a specimen collected on James Cook’s third expedition to Bruny Island off the Tasmanian coast was sent to the British Museum, where the French botanist Charles Louis L’Heritier de Brutelle named it and then published it in 1788.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/where-the-old-things-are-australias-most-ancient-trees-65893">Where the old things are: Australia's most ancient trees</a>
</strong>
</em>
</p>
<hr>
<p>L’Heritier named the specimen <em>Eucalyptus obliqua</em>, and so messmate stringybark is the first named and now type specimen for all <em>Eucalyptus</em> species. Because of the little caps covering the buds of this specimen, the name eucalypt was derived from the Greek <em>eu</em>, meaning “well”, and <em>calyptos</em>, meaning “covered”. Meanwhile, the asymmetrical or oblique leaf base gave us the description <em>obliqua</em>. </p>
<p>The name stringybark comes from the fibrous stringy bark that grows on the trunk of the tree, but no one knows the origins of the name messmate, which is also applied to several other eucalypt species.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=802&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=802&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=802&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1008&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1008&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243630/original/file-20181102-83626-frpdtn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1008&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
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<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Humming with bees</h2>
<p>The flowers are small and white and often go unnoticed – but not by bees, which are often attracted to the trees in such large numbers that the trees seem to be humming. The fruits, or gum nuts, are also small at about 8mm across and usually occur in clusters of three, four or five. The juvenile leaves are quite large, almost heart-shaped, and up to 70mm wide and 100mm long, but the adult leaves are about 50mm wide and up to 200mm long with a sharply acute base on one side.</p>
<p><em>E. obliqua</em> is also commonly known as messmate, stringybark, browntop, Tasmanian or Tassie oak, or browntop stringybark. It is widely distributed through southeastern Australia, growing in Tasmania, Victoria, South Australia and much of New South Wales, almost to the Queensland border. </p>
<p>It is usually a tall straight forest tree that can reach heights of 80m or more, and girths in excess of 10m. It grows in higher and wetter habitats and often grows around other eucalypts such as <em>E. regnans</em>, <em>E. delegatensis</em>, <em>E. viminalis</em> or <em>E. radiata</em>.</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>
<p>The specimens that Cook’s expedition encountered on Bruny Island were huge forest trees, and there are still such specimens growing on the island today. They are well worth a visit along easily accessible tracks. Such giant specimens can also be found on the mainland in places such as the Otway Ranges. However, you can also find examples of <em>E. obliqua</em> growing in the coastal heaths of Victoria that are no more than a metre high and will maintain their short stature regardless of where they are grown. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243632/original/file-20181102-83654-amnxkl.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">Stringybark near Mountain Ash, with a canopy height of around 40m.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/17674930@N07/25592818024/in/photolist-Fsy3Jo-FsxAAw-FsxV8w-DWpjGR-Mgs9uv-23Aorkn-oCe4WK-nswYh2-DWpk3v-pfAeQ2-FsxzDm-22vCuaJ-DWouD6-sqUqtt-D9kQNY-2b2vd9x-28T2UU-zXRxDT-DWoyYP-23AodYP-23xzoyY-Ak3T9b-22vDRvN-Mgs98i-DWoyBX-JDx7Ua-DWpiua-EZxTab-DWpjVg-FuTnxs-23xzqHh-ptaNxU-2b2vdvp-FsymVy-Fsy1o1-sQR2z9-2b2vb3D-Mgs86Z-Mgs8ZH-2b2vbs6-2b2vc7H-2b2vcW8-2b2vdmX-2b2vbUD-s9kbed-ru6zUZ-okJm7j-okK4iz-okJACn-okK2G8">Pete The Poet/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>A tough customer</h2>
<p>One of the great things about messmate stringybark is its environmental resilience. The species is renowned for its adaptations to stress, particularly fire. Its thick stringy bark protects the trunk during bushfires, and under the bark are dormant (or “epicormic”) buds that allow the rapid establishment of a leafy canopy after fire or other stresses such as grazing. These buds often sprout very soon after a fire and are the first sign the forest is beginning to regenerate.</p>
<p>Many of these new shoots will not last very long, but usually enough will survive to reconstitute the tree’s canopy. If all the shoots fail, most specimens have a <a href="http://www.publish.csiro.au/BT/BT9840415">lignotuber</a> (like a mallee root) that allows new stems and trunks to develop after very severe stress. So <em>E. obliqua</em> is truly a tough customer.</p>
<p>During the most recent ice age, Tasmania and the mainland were connected by a land bridge that subsequently disappeared under Bass Strait. The populations of <em>E. obliqua</em> in Victoria and Tasmania were then connected but in the 10,000 years since they have been separated by the strait, the individual trees growing on the mainland have retained a lignotuber, while those in Tasmania did not. This reflects the better growing conditions in Tasmania for messmate stringybark, and less need or stress adaptations.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-fresh-perspective-on-tasmania-a-terrible-and-beautiful-place-104248">A fresh perspective on Tasmania, a terrible and beautiful place</a>
</strong>
</em>
</p>
<hr>
<h2>Good wood</h2>
<p>The timber of <em>E. obliqua</em> is highly prized. It was used by Indigenous communities, as scars on some surviving trees indicate, and its fibrous bark could be used for making fibre and in fires. Today, it is a fine quality hardwood that can be used for building house frames, furniture making or, of course, for wonderful Tassie oak wooden floors. </p>
<p>It is not the densest or hardest eucalypt timber, but is hard enough to make beautiful and durable flooring that polishes to a rich honey or golden colour. Properly installed and maintained, these floors can remain in good condition for well over a century and many Australians will have fond memories of dancing on them.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/unravelling-the-mystery-of-eucalypt-scribbles-11023">Unravelling the mystery of eucalypt scribbles</a>
</strong>
</em>
</p>
<hr>
<p>Messmate stringybark is one of the great trees of Australia for a variety of reasons. It has links to Captain Cook, is an economically important timber species, and is a great survivor in the harsh Australian environment. With its wide distribution and adaptations to fire and other stresses, it is a species likely to cope well with climate change. After all, it is as tough as boots.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=199&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=199&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=199&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=251&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=251&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=251&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://confirmsubscription.com/h/r/9AE707FA51C4AC1B">Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.</a></em></p><img src="https://counter.theconversation.com/content/100528/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>
One of the great Australian trees – messmate stringybark, Eucalyptus obliqua.
Gregory Moore, Doctor of Botany, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/103220
2018-09-28T04:49:29Z
2018-09-28T04:49:29Z
‘The worst kind of pain you can imagine’ – what it’s like to be stung by a stinging tree
<figure><img src="https://images.theconversation.com/files/238270/original/file-20180927-48659-99pg3p.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Even the slightest touch of a D. moroides leaf can cause excruciating pain. An intense stinging, burning pain is felt immediately, then intensifies, reaching a peak after 20 – 30 minutes.
</span> <span class="attribution"><span class="source">Marina Hurley, Author provided</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em>Sign up to the Beating Around the Bush newsletter <a href="https://theconversation.com/au/newsletters">here</a>, and suggest a plant we should cover at <a href="mailto:batb@theconversation.edu.au">batb@theconversation.edu.au</a>.</em></p>
<hr>
<p>Stinging trees grow in rainforests throughout Queensland and northern NSW. The most commonly known (and most painful) species is <em>Dendrocnide moroides</em> (Family <em>Urticaceae</em>), <a href="https://www.jstor.org/stable/4252456">first named</a> “gympie bush” by gold miners near the town of Gympie in the 1860s.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=802&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=802&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=802&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1008&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1008&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238304/original/file-20180927-48656-1awhuoc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1008&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>
</figcaption>
</figure>
<p>My first sting was from a different species <em>Dendrocnide photinophylla</em> (the shiny-leaf stinging tree). It was like being stung by 30 wasps at once but not as painful as being stung by <em>D. moroides</em>, which I <a href="https://www.youtube.com/watch?v=2VS69FXbjN8">once described as</a> the worst kind of pain you can imagine – like being burnt with hot acid and electrocuted at the same time.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/2VS69FXbjN8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An excerpt from a French documentary ‘Plant Secrets’ by director François-Xavier Vives.</span></figcaption>
</figure>
<p>I agreed to study stinging trees even after being badly stung. The puzzle was – what was eating the stinging tree? Stinging trees often have huge holes but no-one knew what was eating them. What could possibly eat the leaves that were so painful to touch? (Read to the end to discover the answer).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238273/original/file-20180927-72336-ckseyu.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">My first sting was from a different species <em>Dendrocnide photinophylla</em> (the shiny-leaf stinging tree)</span>
<span class="attribution"><span class="source">Marina Hurley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/grass-trees-arent-a-grass-and-theyre-not-trees-100531">Grass trees aren't a grass (and they're not trees)</a>
</strong>
</em>
</p>
<hr>
<p>Stinging trees grow in light-filled gaps in the rainforest understorey and come in many different shapes, sizes and species (seven in Australia).</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238272/original/file-20180927-48665-7lcqdc.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"><em>Dendrocnide moroides</em></span>
<span class="attribution"><span class="source">Marina Hurley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>I studied two species for my PhD, <em>Dendrocnide moroides</em> and <em><a href="https://www.jstor.org/stable/41729927?seq=1#page_scan_tab_contents">Dendrocnide cordifolia</a></em> which is often mistaken for <em>Dendrocnide moroides</em>. Both species are shrubs that grow to three metres with <a href="http://www.publish.csiro.au/bt/bt98006">heart-shaped</a>, serrated-edged, dark-green leaves that can grow from the size of a thumbnail to over 50 cm wide.</p>
<p>The sting is caused by stinging hairs that contain toxin and densely cover the leaves, stems and fruit. The thick covering of the hairs makes the leaves look as though they are covered with soft, downy, fur and may give the impression they are inviting to touch. </p>
<p>The fruit of <em>D. moroides</em> is similar to a bright red-dark purple raspberry with long stems, while the fruit of <em>D. cordifolia</em> is always green with short stems that give the fruit a clumped appearance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238046/original/file-20180926-48641-hm9kaz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&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 fruit and leaves of Dendrocnide cordifolia.</span>
<span class="attribution"><span class="source">© Marina Hurley</span></span>
</figcaption>
</figure>
<h2>What it’s like to be stung</h2>
<p>Even the slightest touch of a <em>D. moroides</em> leaf can cause excruciating pain. An intense stinging, burning pain is felt immediately, then intensifies, reaching a peak after 20 – 30 minutes.</p>
<p>The hairs can remain in the skin for up to six months, with stings recurring if the skin is pressed hard or washed with hot or cold water. </p>
<p>Not only do you feel pain from where you are stung, if it is a really bad sting, within about 20 minutes your lymph nodes under your arms swell and throb painfully and feel like they are being slammed between two blocks of wood. </p>
<p>The intense throbbing pain from both the sting and from your lymph nodes can last anywhere from 1-4 hours, depending upon what species you touched, the amount of skin that was stung, and how hard you came into contact with the plant.</p>
<h2>How it works</h2>
<p>The stinging hair structure is complex and <a href="https://www.ncbi.nlm.nih.gov/pubmed/30080249">consists</a> of a tip, shaft and bulb composed of silica, calcium carbonate and calcium phosphate. </p>
<p>The tip of the hair is a small bulb that breaks off on contact, then the hair penetrates the skin injecting toxin. The structure and function of <em>Dendrocnide</em> stinging hairs is similar across five plant families and is described as <a href="https://www.ncbi.nlm.nih.gov/pubmed/30080249">similar to a hypodermic needle</a>.</p>
<p>The composition of the toxin is also complex and still not well understood, including exactly what components actually <a href="http://www.globalsciencebooks.info/Online/GSBOnline/images/0706/FPSB_1(1)/FPSB_1(1)46-55o.pdf">cause the stinging sensation</a>.</p>
<p>The toxin is <a href="https://www.ncbi.nlm.nih.gov/pubmed/13471452">stable and heat resistant</a> and retains its pain-producing properties for decades. Dried botanical specimens collected over 100 years ago, can still sting you. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=459&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=459&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=459&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=577&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=577&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238047/original/file-20180926-48641-1ej2wgp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=577&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An electron micrograph of stinging hairs.</span>
<span class="attribution"><span class="source">© Marina Hurley</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/welcome-to-beating-around-the-bush-wherein-we-yell-about-plants-96993">Welcome to Beating Around the Bush, wherein we yell about plants</a>
</strong>
</em>
</p>
<hr>
<h2>Sting stories</h2>
<p>My worst sting was from a dead, dried-up leaf on the forest floor. I dropped my glove and then drove my finger through the leaf when I went to pick it up. As I was alone at the time, I had to drive to the hospital with one hand.</p>
<p>During my research in the late 80s-early 90s, I heard dozens of stories about people getting badly stung including a letter from an ex-serviceman, Cyril Bromley, who said he was stung after falling into a stinging tree while crossing a creek near the Barron River (North Queensland) in 1941. He said the pain was so bad they had to tie him to his hospital bed for three weeks. He also recounted how an officer had shot himself because he could not stand the pain.</p>
<p>The less well-known and very disturbing thing about stinging trees is they cause intense sneezing, nose bleeds, and possibly major respiratory damage, if you stay close to them for more than about 20 minutes without protection.</p>
<p>The reaction starts with your nose tingling, then dripping continuously. After a short period, you start to sneeze – not just mild sneezing but intense, harsh and continuous bouts of sneezing. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=582&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=582&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238055/original/file-20180926-48662-3ndxqw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=582&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marina Hurley wore a particle face mask and welding gloves when working with stinging trees.</span>
<span class="attribution"><span class="source">© Marina Hurley</span></span>
</figcaption>
</figure>
<p>This happened to me and my field assistants when in close proximity to the plant, either in the rainforest or in the laboratory. Wearing particle face masks helps but they need to be regularly replaced. I believe that this reaction is caused by breathing in the hairs that become air-borne but I have never been able to substantiate this. </p>
<p>Researcher W.V. MacFarlane <a href="https://www.jstor.org/stable/4252456">described</a> his reaction in detail when working with hairs and leaves of D. moroides: </p>
<blockquote>
<p>Mucous membranes are affected by dust or spray from the leaves… Initially they produced sneezing, but within three hours there was diffuse nasopharyngeal pain, and after 26 hours a sensation of an acute sore throat… aching sensations in the sinuses occurred… and a watery nasal discharge that persists for two days. The nasal mucous membranes then begin to slough together with blood, pus and inspissated (thickened) mucus… and discharge of sloughing tissue for 10 days.</p>
</blockquote>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238051/original/file-20180926-48647-s2rrqp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dozens of these nocturnal beetles (Prasyptera mastersi) were found eating the leaves.</span>
<span class="attribution"><span class="source">© Marina Hurley</span></span>
</figcaption>
</figure>
<h2>The mystery solved</h2>
<p>I found out what was eating them: a nocturnal leaf-eating chrysomelid beetle and many other leaf-chewing insects and sap-suckers. </p>
<p>Also, surprisingly, both species of stinging tree were voraciously eaten by the <a href="https://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10805">red-legged pademelons</a> that occasionally stripped entire plants of their leaves overnight. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238269/original/file-20180927-48634-1807u4e.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">A red-legged pademelon. These tough guys eat stinging leaves.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Meanwhile, if you are out and about in the rainforest, stay on the designated paths, and wear closed shoes and long pants.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=199&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=199&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=199&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=251&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=251&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238283/original/file-20180927-48650-1veiqyi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=251&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://confirmsubscription.com/h/r/9AE707FA51C4AC1B">Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.</a></em></p><img src="https://counter.theconversation.com/content/103220/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marina Hurley 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>
Depending on the species, touching a stinging tree can be like 30 wasp stings at once or being burnt with hot acid and electrocuted at the same time.
Marina Hurley, Visiting Fellow, Lecturer & Consultant (Writing Clear Science), UNSW Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/96737
2018-05-24T12:54:37Z
2018-05-24T12:54:37Z
Why plants need an identity
<figure><img src="https://images.theconversation.com/files/220126/original/file-20180523-51091-1vbq7lu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Berzelia stokoei, one of the 3% of plants in South Africa that are found nowhere else in the world.</span> <span class="attribution"><span class="source">Marinda Koekemoer </span></span></figcaption></figure><p>Plant experts in South Africa have a challenging deadline to meet: gather everything that’s known about the country’s 21 000 indigenous plant species into a formal online record by 2020. Fortunately they are well on their way.</p>
<p>It’s not just an academic exercise; it’s to help preserve the world’s biological diversity. The <a href="https://www.sanbi.org/">South African National Biodiversity Institute</a> (SANBI) – also helped in this effort by volunteers – has an important contribution to make as a member of the <a href="http://www.worldfloraonline.org/">World Flora Online</a> (WFO) Consortium. The 41-member group is creating a central record of the world’s plants by 2020. This list, known as a Flora, is a description of all species and where they are found.</p>
<p>The online Flora project addresses three problems that stand in the way of plant species conservation. One is that some plants have not yet been scientifically named. Without a name, they can’t be part of a conservation plan. The second problem is that names can change and multiply, creating confusion for researchers and managers. Thirdly, there is no single collection of information about all the world’s plants.</p>
<h2>Why names matter</h2>
<p>Whenever a new plant species or any other living organism is discovered, it must be named. Through formal naming (the process of taxonomy), a species is clearly defined and described. Its definitive characteristics are highlighted along with its relationships to other species. </p>
<p>The <a href="https://www.iucn.org/">International Union for Conservation of Nature</a> evaluates the risk of extinction of species and informs conservation plans, policies and legislation. But it can only do so for formally recognised living organisms. It can’t protect an undescribed species. </p>
<p>Taxonomy is not a static science. As more information becomes available, taxonomists try to improve classifications. Sometimes they rename species but not everyone uses the same name.</p>
<p>Consistent naming is important because names should precisely match the properties of organisms. Environmental managers need this information to guide their strategies. </p>
<p>Taxonomic information is scattered throughout a vast collection of journals, theses, popular articles, books and electronic sources, some of which can be difficult to access. There is no single, up-to-date source of plant species’ scientific names.</p>
<h2>Global strategy</h2>
<p>A Flora that makes information more accessible and easier to share will support the <a href="https://www.cbd.int/gspc/targets.shtml">Global Strategy for Plant Conservation</a>, which the United Nations’ <a href="https://www.cbd.int/">Convention on Biological Diversity</a> follows. The convention promotes conservation, sustainable use and equitable sharing of genetic resources. </p>
<p>South Africa has signed the convention and therefore takes an active part in carrying out <a href="http://biodiversityadvisor.sanbi.org/planning-and-assessment/plant-conservation-strategy/">the global strategy</a>. </p>
<h2>The World Flora Online</h2>
<p>Compiling the Flora is an immense task. In 2012, the Missouri Botanical Garden, New York Botanical Garden, Royal Botanic Garden Edinburgh and Royal Botanic Garden Kew joined forces and established the World Flora Online to take it on. </p>
<p>The World Flora Online Consortium has since expanded and now has 41 members working together on data aggregation. A first version of the World Flora Online portal was launched in Shenzhen, China in 2017 during the International Botanical Congress and is available online at <a href="http://www.worldfloraonline.org/">http://www.worldfloraonline.org/</a>.</p>
<h2>e-Flora of South Africa</h2>
<p>The South African National Biodiversity Institute became a member of the Consortium in 2013. Approximately 6% of the world’s plants occur in South Africa, and 3% of the plants in South Africa are found nowhere else in the world. </p>
<p>Despite this botanical wealth, South Africa doesn’t have a complete, up-to-date Flora. The last comprehensive Flora was published in the <a href="https://www.biodiversitylibrary.org/bibliography/821#/summary">Flora Capensis in 1933</a> and dealt with about 11 500 species known at the time. That number has almost <a href="http://newposa.sanbi.org/">doubled</a> since then. </p>
<p>The global strategy deadline of 2020 does not allow enough time to follow traditional methods of producing a Flora. Instead, existing information is being gathered from taxonomic treatments, monographs and conspectuses into an <a href="https://doi.org/10.12705/662.9">electronic Flora</a>. </p>
<p>South Africa is making good progress with this project. Information for almost 85% of species has been collected and the first set of data will be on the <a href="http://www.worldfloraonline.org/">World Flora Online portal</a> this year.</p>
<p>The e-Flora will be maintained beyond 2020: good news for plant conservation in South Africa and internationally.</p><img src="https://counter.theconversation.com/content/96737/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marianne Le Roux works for the South African National Biodiversity Institute.
I am a Research Associate at the University of Johannesburg.</span></em></p>
There is good news for plant conservation in South Africa and internationally.
Marianne Le Roux, e-Flora Coordinator, South African National Biodiversity Institute
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/77873
2017-06-20T20:00:44Z
2017-06-20T20:00:44Z
Curious Kids: how can a tiny seed actually grow into a huge tree?
<figure><img src="https://images.theconversation.com/files/170255/original/file-20170522-12242-xbrstx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Once the coat around the seed is moistened, the embryo cells expand and burst out in a process called germination.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tree-growing-596239349?src=tQn14rOWZYWbLKuPfCcxhQ-2-34">shutterstock/NUM LPPHOTO</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a new series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!</em> </p>
<hr>
<blockquote>
<p><strong>How can a tiny seed actually grow into a huge tree? – Finney, aged 6, from Bairnsdale in rural Victoria.</strong> </p>
</blockquote>
<p>Tree seeds fall (like the tiny <a href="http://www.environment.nsw.gov.au/resources/cpp/SeedCollecting.pdf">Eucalypt seeds</a>) or <a href="https://youtu.be/H2h8zGXcdeA">helicopter down</a> (like the winged seeds of the Maple) from their parents with a full set of instructions on how to grow. </p>
<p>A single tree may drop hundreds or even many thousands of seeds. Many of these seeds will become snacks for insects or fall where the ground is too hard, too dry, or just not suitable for trees. Some though will fall where the situation is <em>just right</em>!</p>
<p><em>Just right</em> might mean bare dirt or some nice decayed mulch with enough sunlight. </p>
<p>The seed contains an embryo - a group of cells ready to form roots, a stem and the first leaves. Once the coat around the seed is moistened, the embryo cells expand and burst out in a process called <em>germination</em>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/oDBX2gCXxYw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Time-lapse of seed germination.</span></figcaption>
</figure>
<p>First, the roots will develop and push out and down into the soil to make sure the new plant can get water. Then the stem cells stretch up to display the first leaves.</p>
<p>The embryo uses food stored in the seed to power its initial growth until the leaves can start producing food. Small seeds don’t have much stored food so they have to fall in just the right spot to be successful. The parent tree has some ways to improve the chances of its seed finding the right spot, like dropping seeds after a bushfire has made the ground bare and free from other plants that would use all the water and nutrients. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/174327/original/file-20170618-28802-wpmnub.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>
<figcaption>
<span class="caption">For some plants, a bushfire triggers the release of seeds.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/tgerus/15835111512/in/photolist-q8i5Y1-3n1MnR-V56iRp-UFxtPW-ojK1UU-V3HtAW-UFxu5A-99Uwhx-dJWpU3-9cQ3XU-4BQgoQ-4us3Nd-4us3PG-roGUB-96mqc1-NUU9Hi-oPQ8Rc-8sXyNX-tZQX5W-7xkPs4-HDCAqf-9sw52V-dSfTeW-2vVkpu-G7C3Eq-UFxunE-Hk1p2U-4Re5xN-U392SX-TZgM2Y-TZgMBf-UFxu1s-TZgMch-UFxuj3-V56iY8-UFxuAA-iD1sPt-TZgMf3-drh2bh-dmY3FA-e4R3Y5-TZgM91-s9dGx1-8wwv63-8n6psZ-8aX6sj-42ryhN-TZgNJA-bpCrbH-cZhNXq">Flickr/Tatters</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Once the roots are in the soil and the first leaves are in the sun, the plant is ready to really start growing.</p>
<p>People stop growing after they’ve become grown-ups but trees just keep getting taller and thicker <a href="https://theconversation.com/where-the-old-things-are-australias-most-ancient-trees-65893">however long they are alive</a>.</p>
<p>Grass, bamboo and many other plants grow from the bottom up, so if you put a mark on the stem and come back in a little while, that mark will have been pushed further above the ground. But if you put a mark or even nail a board into a tree at one metre above the ground then come back in 10 years, it will still be only one metre above the ground. That’s because trees grow from the outside and the top up.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/173695/original/file-20170614-30051-uzryv7.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">Some trees can grow to be more than 100 metres tall!</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/andrewmalone/15297310345/in/photolist-piLHq6-6hzRUp-nh1DqC-Tj3neM-dc9o5t-9qh5V9-NFjM-8ipn6M-bcF3Vr-a4EFQo-q4TRdJ-6D2yDf-8XLL1R-4fpU5a-7j8en1-8tQ8FU-7x4Xeo-dZezUd-32RoN8-5PBCa5-6wkGez-zU6nRp-rEJq34-n5Fr4b-QTmnVs-pMU63a-qeUjY2-jjn4xH-dRR69p-4Xbx1K-poJXKq-gsdG9U-4uTgBe-cfMqBS-qaUCFu-9sYxFp-3obaZA-TCVyaM-6ETVoM-TUqcbR-4F1pC8-8Mx1YQ-pAX1if-UZGUWq-aEEiMn-fsu4zt-57Efuj-jLdSZB-oGEXGm-8W2QeY">Flickr/Andrew Malone</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The newest and outer shell of a tree contains all the living parts of the wood - the parts that move water up from the roots and food down from the leaves. If trees stop growing these outer, living shells of wood, the whole tree dies.</p>
<p>Some trees can grow to be more than 100 metres <a href="http://www.abc.net.au/news/2017-01-24/photographing-one-of-the-worlds-tallest-trees-in-styx-valley/8206910">tall</a> – that’s as tall as a skyscraper! In fact, humans are now building <a href="https://www.therealestateconversation.com.au/2017/02/09/worlds-tallest-wooden-office-tower-planned-brisbane/1486592503">buildings out of wood that are over 50 metres tall</a> and there are plans to go well beyond that.</p>
<p>The tallest tree currently is over 110 metres tall, and scientists think some trees may have been as much as 150 metres tall.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/4BtKAkP5xOk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Trees grow from the top up.</span></figcaption>
</figure>
<p>A problem with getting even taller is that trees use water the same as you use blood - to move the nutrients and oxygen and other vital things around our body. But a tall tree has to move it from the roots to the tip of the leaves. For a 100 metre tall tree, that is like 30 flights of stairs. And a big tree could use more than 200 litres of water every day. Imagine carrying 30 buckets of water up 30 flights of stairs every day! </p>
<p>In our tall buildings, we need huge pumps and generators to move the water to the top, but trees just rely on their amazing structure and a little bit of power from the Sun.</p>
<hr>
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<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age, and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/77873/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cris Brack 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>
A seed contains nearly everything a tree needs to get growing. Just add a dash of water, a bit of warmth and the right location, and you’ll be seeing green in no time.
Cris Brack, Assoc Professor Forest measurement & management, Australian National University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/76918
2017-05-09T14:16:34Z
2017-05-09T14:16:34Z
Curious Kids: What plants could grow in the Goldilocks zone of space?
<figure><img src="https://images.theconversation.com/files/167267/original/file-20170430-13003-h72pjp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Almost every star has planets – so there are more planets in our galaxy than there are stars. </span> <span class="attribution"><span class="source">NASA Ames/JPL-Caltech/T. Pyle</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a new series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!</em> </p>
<hr>
<blockquote>
<p>What plants could grow in the Goldilocks zone of space? <strong>– Jesse, 9, Miranda.</strong></p>
</blockquote>
<p>Imagine a planet like the Earth, orbiting a distant star. Could that planet have life? Well, life on Earth (the only life we know) needs liquid water. So to find life on another planet, we think that that planet would have to be “just right”.</p>
<p>If the planet is too close to its star, it will be too hot, and any oceans would boil. Too distant, and any oceans would freeze. Somewhere in between lies the “Goldilocks Zone” - not too hot, not too cold, but just right. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167297/original/file-20170430-13007-1m0bzvf.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">The ‘Goldilocks Zone’ for the Solar system and the TRAPPIST-1 system. Too close to the star, you’d be too hot (red). Too distant, and you’d be too cold (blue). In between, things might be just right for liquid water…</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech</span></span>
</figcaption>
</figure>
<p>We still haven’t discovered life on any other planet, so we can’t say for sure what such life would be like. One thing is certain, though - alien life will be very, very different to anything on Earth. </p>
<p>We can try to imagine plants that could live on other planets based on the facts we <em>do</em> have. Using your imagination like this is a very important part of being a scientist, trying to explore the vast ocean of the unknown.</p>
<h2>So many planets</h2>
<p>One thing we’ve learned over the last 20 years is that planets are everywhere. Almost every star has planets – so there are more planets in our galaxy than there are stars. </p>
<p>“Goldilocks planets” could be bigger or smaller than the Earth. Smaller ones have weaker gravity, so you would weigh far less there than on the Earth. Plants (and animals!) growing there could easily be much taller than on Earth, since it would be easier for them to grow up! </p>
<p>On a bigger planet, more massive than Earth, plants would probably be much shorter – thanks to the stronger gravity on such a world. We can work out how strong gravity would be on different planets. This <a href="https://www.exploratorium.edu/ronh/weight/">cool website</a> lets you work out how much you would weigh on other objects in the Solar system, for example.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167295/original/file-20170430-13003-j98tjr.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">On the left, the Earth. To the right, Earth’s bigger cousin. On a more massive planet, gravity would be stronger - which would have a big effect on any life that evolved!</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<h2>Water, wind and light</h2>
<p>Also, not all planets are equally wet. Some are likely dry, desert worlds, while other “Earth-like” worlds might <a href="https://theconversation.com/giant-impacts-planet-formation-and-the-search-for-life-elsewhere-33478">have oceans tens, or hundreds of kilometres deep</a>. What kind of plants could grow on those desert or water worlds?</p>
<p>If a “Goldilocks planet” had a thin atmosphere (like Mars), even the strongest winds would push more gently than a soft breeze here on Earth. Any plants probably wouldn’t need to be very strong to protect against bad weather. With a really thick atmosphere, though, winds push harder – and any plants in those conditions would have to evolve to be really tough.</p>
<p>And then we get to light. Plants on Earth have evolved to use the light from the Sun to get their energy, using a chemical called chlorophyll. It absorbs blue and red light, but reflects green light. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167296/original/file-20170430-12970-q19l5i.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">Sunset on a planet around a red dwarf star. What kind of life would thrive under a red Sun?</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech</span></span>
</figcaption>
</figure>
<p>That chemical is really useful for Earth plants, because the Sun gives off lots of energy in the blue and the red. But imagine a dull, cool, red star. That star would be red because it doesn’t give off much yellow or blue light – and so plants using chlorophyll would starve! </p>
<p>But there are probably lots of other chemicals that plants on those worlds could use to live under their own suns. There may even be life on planets out there with more than one sun - with each star a different colour in the daylight sky!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167294/original/file-20170430-12979-19lcj4m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&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 world with two suns, orbiting a giant planet (like Jupiter). What kind of life could thrive on such a world?</span>
<span class="attribution"><span class="source">IAU/L. Calçada</span></span>
</figcaption>
</figure>
<p>Put all that together and you have lots of fuel for your imagination! Plants that are different colours to those on Earth, using different coloured starlight. Tall, wispy plants, living on worlds with low gravity and thin atmospheres. Squat, low, strong plants on worlds that are massive, or have thick atmospheres. </p>
<p>Plants on other planets are bound to be even weirder than the strangest ones we find on Earth – and probably stranger than we can even imagine!</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:</em></p>
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<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age, and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/76918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jonti Horner 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>
Plants on other planets are bound to be even weirder than the strangest ones we find on Earth – if they even exist.
Jonti Horner, Vice Chancellor's Senior Research Fellow, University of Southern Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/48895
2015-10-25T19:13:24Z
2015-10-25T19:13:24Z
We need to stop Australia’s genetic heritage from being taken overseas
<figure><img src="https://images.theconversation.com/files/99281/original/image-20151022-8031-qx2a0i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">_Nicotiana benthamiana_ growing in the wild in coastal northern Western Australia.</span> <span class="attribution"><span class="source">Steve Wylie</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In August this year <a href="http://www.kew.org/science-conservation/research-data/science-directory/people/chase-mark-w">Professor Mark Chase</a> from the <a href="http://www.kew.org/">Royal Botanical Gardens</a> at Kew, west of London, flew into Perth in Western Australia, hired a 4WD vehicle and drove north.</p>
<p>After clocking up 9,000km he told me he had collected seed from thousands of plants of nine species and subspecies belonging to one genus. This genetic resource is now catalogued and stored in England. He had done the same in South Australia in 2014 and plans to repeat the exercise in WA in 2016. </p>
<p>Let’s be clear upfront. Chase is no <a href="http://www.jstor.org/stable/10.1086/508502">bio-pirate</a>, he’s a respected professor and everything he did was perfectly legal and above board.</p>
<p>So what’s the problem?</p>
<h2>A brief history of rubber</h2>
<p>Consider rubber. In the 1800s there was a rubber boom. Rubber trees are indigenous to the Amazon basin and Brazil was making a fortune.</p>
<p>In 1876 Kew Gardens commissioned <a href="http://westernfarmpress.com/blog/when-rubber-ruled-world">Henry Wickham</a> to steal rubber tree seeds. They were planted in the British colonies of Ceylon and Malaya forming the basis of a successful industry for the then British Empire. Brazil’s rubber boom ended.</p>
<p>Back to present-day Australia. The plants collected by our visiting professor all belong to Western Australian native members of the genus <em><a href="https://florabase.dpaw.wa.gov.au/browse/profile/22036">Nicotiana</a></em>, a cousin of tobacco, potato, tomato, eggplant and capsicum. The name looks familiar because of nicotine, a psychoactive alkaloid of tobacco, <em>Nicotiana tabacum</em>, which is native to the Americas. The Spanish took it to Europe in the 1500s. Shipping <em>Nicotiana</em> seeds between continents has a long history. </p>
<p>For thousands of years Australian Aboriginal peoples have used <em>Nicotiana</em> in religious practice, for medicinal purposes and recreationally. Near the end of August in 1770, Joseph Banks was aboard James Cook’s ship Endeavour observing the local people who lived on the northern coast of Australia. He <a href="http://gutenberg.net.au/ebooks05/0501141h.html#aug1770">wrote</a>:</p>
<blockquote>
<p>We observd that some tho but few held constantly in their mouths the leaves of an herb which they chewd as a European does tobacca […]</p>
</blockquote>
<p>They were almost certainly chewing <a href="http://link.springer.com/article/10.1186/1746-4269-6-26">Pituri</a>, made from dried <em>Nicotiana</em> leaves rolled in ash. The alkalinity of the ash releases nicotine. Native tobacco is still of cultural significance to groups of indigenous Australians.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/99282/original/image-20151022-8006-1asmj7i.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"><em>Nicotiana benthamiana</em> (left) from the Northern Territory and the same species (right) from northern Western Australia.</span>
<span class="attribution"><span class="source">Steve Wylie</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Interest from overseas</h2>
<p>The Kew professor is not the first foreign scientist to come to Australia collecting <em>Nicotiana</em>. Illustrations of Australian <em>Nicotiana</em> plants in a series of <a href="http://www.flora.sa.gov.au/efsa/lucid/Solanaceae/Nicotiana%20species/key/Australian%20Nicotiana%20species/Media/Html/index.htm#N">Fact Sheets</a> by the South Australian herbarium borrow heavily from The Genus Nicotiana Illustrated, a book published by Japan Tobacco in 1994. </p>
<p>Why the international interest in Australian <em>Nicotiana</em> species? Our English professor said his interest lay in clarifying the taxonomic status of the Australian members of the genus. But detailed <a href="http://www.publish.csiro.au/paper/SB11006">taxonomic studies</a> have already been done at the University of Melbourne: so collections of thousands of plants are not required for this purpose. </p>
<p><a href="http://apsjournals.apsnet.org/doi/abs/10.1094/MPMI-21-8-1015"><em>Nicotiana benthamiana</em></a> is Australia’s most scientifically famous native plant, grown in labs around the world. It grows naturally across northern WA.</p>
<p>Its immense value to science lies in two inter-related properties. It’s extraordinarily susceptible to plant pathogens and so has been invaluable in helping understand how to control diseases in crops.</p>
<p>It also has the unusual ability to express proteins of many foreign genes – this made it the species of choice for GlaxoSmithKline when developing an experimental <a href="http://www.nature.com/nbt/journal/v32/n9/full/nbt0914-849a.html">Ebola virus vaccine</a> in response to the 2014 outbreak in Africa. The world has already benefited from <em>Nicotiana benthamiana</em> in many ways.</p>
<h2>Crops of the future</h2>
<p>A worldwide race is underway to develop tough new crops able to withstand the drought, heat and disease coming with climate change. Kew Gardens publishes a <a href="http://www.kew.org/discover/blogs/kew-science/crop-wild-relatives-creating-guides-seed-collectors">guide</a> for bio-prospectors to collect seed from wild plants for their <a href="http://www.kew.org/science-conservation/research-data/science-directory/projects/adapting-agriculture-climate-change">Adapting Agriculture to Climate Change</a> project.</p>
<p>Australian <em>Nicotiana</em> species from arid zones have evolved a suite of genetic tricks to cope with the notoriously unpredictable rainfall and severe heat. They live in small, scattered populations of favourable habitat, isolated from other populations by inhospitable dry rocks and sands.</p>
<p>Over time, nature has experimented with these isolated populations, tested new ways to survive. Our research at Murdoch University has already shown that each distinct population exhibits markedly different responses to drought and <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0121787">virus attack</a>. </p>
<p>Our Kew professor is attempting to sample all the genetic variety present within each Australian <em>Nicotiana</em> population so that the best genes from them may one day be selected for agriculture, or perhaps other uses. Stress tolerance genes that evolved in the deserts of Australia could one day protect fields of wheat, maize, potatoes and other crops so fundamental to our survival.</p>
<p>So where is the problem? We might applaud the noble quest of agricultural scientists to save the world from famine, irrespective of their geographical location. </p>
<h2>Australia’s rich resource</h2>
<p>The problem is the means by which this outcome will be achieved. Australia’s scientists should be mining Australia’s gene bank, and all Australians should benefit from the rewards of this intellectual property (<a href="https://theconversation.com/au/topics/intellectual-property">IP</a>).</p>
<p>International collaboration is the lifeblood of scientific advancement, but so is competition and protecting IP. When Australia’s genetic heritage is lodged in other countries, we have lost control of our IP.</p>
<p>Most of Australia’s mineral heritage has been sold cheaply as unprocessed ore. Our international customers increase its value many-fold through innovative manufacturing. Then we buy it back. </p>
<p>Should we follow the same path with our genetic heritage so that one day Australian farmers will be forced to buy from overseas agricultural companies new drought-tolerant crop varieties sporting Australian genes? Or should we build genetic IP in Australia for the sustainable benefit of Australians?</p>
<p>But the collection and export of Australian native genetic resources remains completely legal. The Kew professor obtained a state government <a href="http://www.dpaw.wa.gov.au/plants-and-animals/licences-and-permits/135-flora-licences">Flora license</a> permitting seed collection on WA crown lands, and a Regulation 4 Authority for collection in WA National Parks and reserves.</p>
<p>Exporting seed from Australia was also legal under the federal government’s <a href="http://www.environment.gov.au/biodiversity/wildlife-trade/natives/list-exempt-native-specimens">Environment Protection and Biodiversity Conservation Act 1999</a>. Who can blame him then for helping himself to Australia’s genetic resources? The door was wide open and a welcome sign was swinging above.</p>
<p>Australia is a lucky country. It has all the features needed to lead the world in the next great agricultural revolution. It has extensive farmlands, educated and technologically aware farmers, and world-class scientists.</p>
<p>What is under-appreciated by Australian governments is the vast wealth potential lodged in the genomes of its precious native flora and fauna. It can be assigned a quantifiable dollar value that could one day be far greater than that of our mineral wealth.</p>
<p>For this and many other reasons it’s critical that state and federal governments protect Australia’s wildlife, and legislate to prevent foreign interests raiding our genetic heritage before more is lost.</p><img src="https://counter.theconversation.com/content/48895/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Wylie 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>
Australia’s risks losing its valuable native plants that could help solve a global food problem. So do we need new laws to stop the seeds being taken overseas?
Steve Wylie, Senior research associate in plant virology, Murdoch University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/3453
2011-09-20T04:39:05Z
2011-09-20T04:39:05Z
Spending to save: what’s the best use of our conservation dollar?
<figure><img src="https://images.theconversation.com/files/3751/original/Mimetes_CGHNR_-_fynbos_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research done in South Africa can guide Australian conservation managers on where to focus effort.</span> <span class="attribution"><span class="source">Brian van Wilgen</span></span></figcaption></figure><p>It’s true: many species will go extinct due to the direct and indirect impacts of climate change.</p>
<p>We will have to make some hard decisions about where to invest conservation dollars for the best effect. So, <a href="http://www.abc.net.au/news/2011-09-19/endangered-species-given-new-hope/2906872">how do we minimise the number of species we will lose</a>?</p>
<h2>Extinctions are on the up and climate change will make it worse</h2>
<p>Climate change will exacerbate the many existing threats to species, including habitat loss, over exploitation and invasive species.</p>
<p>This is not news to ecologists. Dire predictions about climate change’s <a href="http://www.climatechange.gov.au/publications/biodiversity/biodiversity-climatechange.aspx">impacts on species</a> and ecosystems are easy to find in the <a href="http://eprints.whiterose.ac.uk/83/">scientific literature</a> and the <a href="http://theconversation.com/with-rapid-global-change-what-is-a-native-species-1294">popular media</a>. </p>
<p>But what are we going to do about it? </p>
<p>We have limited control over global warming, we have little money with which to protect species and we have many possible courses of action, only a portion of which can we afford to try. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=604&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=604&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3733/original/fynbos_flowers_RobW.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=604&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fynbos natives.</span>
<span class="attribution"><span class="source">RobW/Flickr</span></span>
</figcaption>
</figure>
<p>From the perspective of conservation scientists and practitioners, the question is how best to invest limited conservation and climate adaptation resources to minimise the number of species going extinct.</p>
<p>This is the question we set out to tackle in a recent climate adaptation research project funded by Australia’s <a href="http://www.environment.gov.au/biodiversity/science/nerp/">National Environment Research Program</a> and the <a href="http://www.arc.gov.au/ncgp/ce/environmental_decisions.htm">ARC Centre of Excellence for Environmental Decisions</a>.</p>
<h2>Getting the best bang for your conservation buck</h2>
<p>We approached this question using a combination of ecological and economic models that help us to:</p>
<p>1) predict the probability that a species will go extinct under a set of climate change scenarios</p>
<p>2) predict how much extinction risk can be reduced by implementing particular conservation actions</p>
<p>3) estimate the cost of implementing those actions</p>
<p>4) figure out the most cost-effective portfolio of conservation actions for a given budget, based on the above estimates of extinction risk reduction and cost.</p>
<p>In short, we figure out how to provide the “best bang for our conservation buck”.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3750/original/fynbos_after_fire_-_van_wilgen.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The post-fire landscape in South Africa’s Fynbos.</span>
<span class="attribution"><span class="source">Brian van Wilgen</span></span>
</figcaption>
</figure>
<p>While this sounds fairly logical, the primary challenge is coming up with the best possible estimates of conservation benefit (reduced extinction risk across multiple species), and management costs. </p>
<p>There are a number of factors that make this a significant challenge:</p>
<ul>
<li><p>global warming scenarios are inherently uncertain </p></li>
<li><p>we don’t know exactly how global change will influence local weather patterns</p></li>
<li><p>we have a relatively poor understanding of ecological processes that mediate particular species extinction risk</p></li>
<li><p>the number of species at risk is huge</p></li>
<li><p>we don’t know enough about the effectiveness of management</p></li>
</ul>
<h2>Applying this approach in South Africa</h2>
<p>Our first attempt at an ecological-economic model was published on September 18 in the journal <a href="http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1227.html">Nature Climate Change</a>. We showed how our approach can be applied to make conservation investment decisions to conserve species in the <a href="http://wwf.panda.org/what_we_do/where_we_work/fynbos/">South African Fynbos Biome</a> – a global biodiversity hotspot of phenomenal beauty.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3735/original/leucadendron_derekkeats.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">
<figcaption>
<span class="caption">Fynbos leucadendron.</span>
<span class="attribution"><span class="source">derekkeats/Flickr</span></span>
</figcaption>
</figure>
<p>The <a href="http://www.youtube.com/watch?v=6JUL_2nddwI">fynbos ecosystem</a> supports more than 6,200 endemic plant species in an area less than the size of Tasmania. Many of those species are highly threatened by the direct and indirect impacts of climate change and the increased frequency and intensity of fires.</p>
<p>These threats compound the already severe impacts of habitat loss (land clearing) and weed invasion.</p>
<p>In collaboration with Brian van Wilgen from <a href="http://www.csir.co.za/">CSIR</a> South Africa, we developed mathematical models to predict the risk of extinction (by 2050) for a set of fynbos Proteas and Leucadendrons (both flowering shrubs). We considered these extinction risks under a range of fire management, weed management and habitat protection investment scenarios and using the IPCC’s <a href="http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html">A1FI climate change projection</a>. </p>
<p>Using these models, we identified the most cost-effective portfolio of conservation investment for reducing extinction risk of fynbos species. </p>
<p>So, what did we find?</p>
<p>Well, under a no-extra-investment scenario, with current habitat loss rates and climate change, the average risk of extinction by 2050 was more than 90% for many species.</p>
<p>We found that if conservation budgets were increased by around US$60 million per year, mostly allocated to early-strike fire suppression, we could reduce the average extinction risk to below 20% – a significant reduction.</p>
<p>This risk could be reduced to less than 10% with a further increase to US$120 million per year, spread fairly evenly across habitat protection and fire suppression.</p>
<p>This is the first time (we think) that anybody has been able to quantify the marginal benefits of increasing conservation spending in terms of reducing extinction risk to species; something we believe to be a very powerful policy tool.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3738/original/leucadendron_cssk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3738/original/leucadendron_cssk.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">Australian leucadendron.</span>
<span class="attribution"><span class="source">cssk/Flickr</span></span>
</figcaption>
</figure> <p></p>
<h2>How will it work in Australia?</h2>
<p>So, what does this all mean for Australian species and how we should be managing ecosystems in order to reduce climate-change driven extinctions? </p>
<p>The first point to make is that conservation investment questions faced by managers of the fynbos are very similar to those faced in Australia and in other parts of the globe.</p>
<p>Namely, how should I allocate my limited budget across a set of possible management actions to achieve the best conservation outcome?</p>
<p>The Fynbos Biome is known as a “Mediterranean” climate ecosystem, similar to ecosystems in Australia, including the biodiversity hotspots in <a href="http://www.biodiversityhotspots.org/xp/Hotspots/australia/Pages/default.aspx">south-western Australia</a>. </p>
<p>The impacts of climate change on fire dynamics and how those changes will impact Australian species are important questions that are currently being addressed by <a href="http://www.latrobe.edu.au/zoology/research/mallee-fire/index.html">a number of Australian scientists</a>.</p>
<p>We hope to be able to work with these experts to implement the sort of ecological-economic analyses described above.</p>
<p>Although ecological-economic analyses such as ours provide just one of many inputs to real-world decision-making, more widespread application of these approaches will help reduce the politicisation of conservation decisions, thereby enhancing the credibility of those who make them.</p>
<p><em>For more information about Brendan’s research, watch the <a href="http://www.abc.net.au/news/2011-09-19/endangered-species-given-new-hope/2906872">video</a> that featured on the 7pm bulletin of ABC News Melbourne on September 19.</em></p><img src="https://counter.theconversation.com/content/3453/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brendan Wintle receives funding from the Australian Research Council (Future Fellowship and the Centre of Excellence for Environmental Decision), and the National Environment Research Program (DSEWPC). Brendan would like to acknowledge the contributions of coauthors: Sarah Bekessy (RMIT University) David Keith (UNSW and NSW DECC) Brian van Wilgen (CSIR South Africa) Mar Cabez (University of Helsinki) Boris Schröder (University of Potsdam) Silvia Carvalho (Universidade do Porto) Alessandra Falcucci, Luigi Maiorano, Carlo Rondinini, Luigi Boitani (URoma) Tracey Regan (University of Melbourne) Hugh Possingham (University of Queensland)</span></em></p>
It’s true: many species will go extinct due to the direct and indirect impacts of climate change. We will have to make some hard decisions about where to invest conservation dollars for the best effect…
Brendan Wintle, Professor Conservation Ecology, Director NESP Threatened Species Recovery Hub, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.