tag:theconversation.com,2011:/us/topics/roots-36376/articlesRoots – The Conversation2024-02-13T13:20:14Ztag:theconversation.com,2011:article/2151272024-02-13T13:20:14Z2024-02-13T13:20:14ZFlowers grown floating on polluted waterways can help clean up nutrient runoff and turn a profit<figure><img src="https://images.theconversation.com/files/573604/original/file-20240205-30-14awa7.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6173%2C4087&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The cut flowers could pay for themselves and even turn a profit.</span> <span class="attribution"><span class="source">Margi Rentis</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Flowers grown on inexpensive floating platforms can help clean polluted waterways, over 12 weeks extracting 52% more phosphorus and 36% more nitrogen than the natural nitrogen cycle removes from untreated water, according to our <a href="https://doi.org/10.1016/j.envadv.2023.100405">new research</a>. In addition to filtering water, the cut flowers can generate income via the <a href="https://www.ers.usda.gov/data-products/chart-gallery/gallery/chart-detail/?chartId=106472">multibillion-dollar floral market</a>. </p>
<p>In our trials of various flowers, giant marigolds stood out as the most successful, producing long, marketable stems and large blooms. Their yield matched typical <a href="https://www.lsuagcenter.com/articles/page1662131594449">flower farm production</a>.</p>
<h2>Why it matters</h2>
<p><a href="https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution">Water pollution</a> is caused in large part by runoff from farms, urban lawns and even septic tanks. When it rains, excess phosphorus, nitrogen and other chemicals wash into lakes and rivers.</p>
<p>These nutrients feed algae, leading to widespread and harmful algae blooms, which can severely lower oxygen in water, creating “<a href="https://unstats.un.org/sdgs/report/2021/goal-14/">dead zones</a>” where aquatic life cannot survive. Nutrient runoff is a critical issue as urban areas expand, affecting the health of water ecosystems. </p>
<p>Water pollution is an escalating crisis in our area of Miami-Dade and Broward counties in Florida. The <a href="https://storymaps.arcgis.com/stories/b5d43852c8984a4c8db4d077ec04bd35">2020 Biscayne Bay fish kill</a>, the largest mass death of aquatic life on record for the region, serves as a stark reminder of this growing environmental issue.</p>
<h2>How we do our work</h2>
<p>We study <a href="https://case.fiu.edu/earth-environment/agroecology/">sustainable agriculture</a> and <a href="https://crestcache.fiu.edu/">water pollution</a> in South Florida.</p>
<p>Inspired by traditional floating farm practices, including the Aztecs’ <a href="https://www.bbc.com/travel/article/20221009-the-return-of-aztec-floating-farms">chinampas in Mexico</a> and the <a href="https://www.pbs.org/video/the-secret-islands-of-the-everglades-lncj6r/">Miccosukees’ tree island settlements in Florida</a>, we tested the idea of growing cut flowers on floating rafts as a way to remove excess nutrients from waterways. Our hope was not only that the flowers would pay for themselves, but that they could provide jobs here in Miami, the center of the U.S. cut-flower trade.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An outdoor tank contains a large floating perforated mat. Each hole contains a young plant." src="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.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">Chemical conditions in the test tanks were the same as in nearby polluted waterways.</span>
<span class="attribution"><span class="source">Jazmin Locke-Rodriguez</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
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<p>We floated 4-by-6-foot (1.2-by-1.8-meter) mats of inexpensive polyethylene foam called <a href="http://www.beemats.com/">Beemats</a> in 620-gallon (2,300-liter) outdoor test tanks that mirrored water conditions of nearby polluted waterways. Into the mats we transplanted flower seedlings, including zinnias, sunflowers and giant marigolds. The polluted tank water was rich in nutrients, eliminating the need for any fertilizer. As the seedlings matured into plants over 12 weeks, we tracked the tanks’ improving water quality. </p>
<p>Encouraged by the success of the marigolds in our tanks, we moved our trials to the nearby canals of Coral Gables and Little River. We anchored the floating platforms with 50-pound (22.7-kilograms) weights and also tied them to shore for extra stability. No alterations to the landscape were needed, making the process simple and doable.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Closeup photo of base of a marigold plant showing a tangle of visible roots." src="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some plants grow roots in places – such as the stem – other than where their original roots began.</span>
<span class="attribution"><span class="source">Jazmin Locke-Rodriguez</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>What still isn’t known</h2>
<p>The success of the giant marigolds might be linked to the extra roots that grow from their stems known as <a href="https://propg.ifas.ufl.edu/05-cuttings/01-terminology/01-cuttingterms-adventitiousroot.html">adventitious roots</a>. These roots likely help keep the plants stable on the floating platforms. Identifying additional plants with roots like these could help broaden plant choices. </p>
<p>Future raft designs may also need modifications to ensure better stability and growth for other cut-flower and crop species. </p>
<h2>What’s next</h2>
<p>Our promising findings show floating cut-flower farms could be a sustainable option for mitigating water pollution. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/Nim52wi_4z4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How floating cut-flower farms can clean polluted waterways.</span></figcaption>
</figure>
<p>One of us (Locke-Rodriguez) is expanding this research and working to scale up floating farms in South Florida as a demonstration of what could take place in the many locations facing similar issues worldwide.</p>
<p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take on interesting academic work.</em></p><img src="https://counter.theconversation.com/content/215127/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jazmin Locke received funding from the USDA-NIFA-NNF and NSF-CREST as a PhD student to help fund this dissertation research at Florida International University.</span></em></p><p class="fine-print"><em><span><a href="mailto:jayachan@fiu.edu">jayachan@fiu.edu</a> receives funding from USDA-NIFA. </span></em></p>Phosphorus and nitrogen contribute to water pollution and cause harmful algal blooms. New research shows how mats of floating flower beds can take advantage of these nutrients while cleaning the water.Jazmin Locke-Rodriguez, Post Doctoral Associate in the Institute of Environment, Florida International UniversityKrishnaswamy Jayachandran, Professor of Agroecology, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2203502024-01-09T17:02:21Z2024-01-09T17:02:21ZPlant roots mysteriously pulsate and we don’t know why – but finding out could change the way we grow things<figure><img src="https://images.theconversation.com/files/568410/original/file-20240109-21-g9babz.jpg?ixlib=rb-1.1.0&rect=49%2C12%2C8130%2C5199&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/farmer-close-holding-picking-green-lettuce-2311127081">Nikita M production/Shutterstock</a></span></figcaption></figure><p>You probably don’t think about plant roots all that much – they’re hidden underground after all. Yet they’re continually <a href="https://nature.com/articles/s41561-022-00995-2">changing the shape of the world</a>. This process happens in your garden, where plants use invisible mechanisms for their never-ending growth.</p>
<p>Scientists discovered <a href="https://journals.biologists.com/dev/article/134/4/681/52968/Auxin-dependent-regulation-of-lateral-root">about 15 years ago</a> that genes at the root tip (or more precisely, the level of proteins produced from some genes) seem to pulsate. It’s still a bit of a mystery but recent research is giving us new insights. </p>
<p>What we do know is this oscillation is a basic mechanism underlying the growth of roots. If we better understood this process, it would help farmers and scientists design or choose the best plants to grow in different types of soil and climate. With increasingly extreme weather such as droughts and floods, <a href="https://www.nature.com/articles/s43017-023-00491-0">damaging crops</a> around the world, it is more important to understand how plants grow than ever before. </p>
<p>To really understand how plants grow, you need to look at processes which happen inside cells. There are <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202303396">numerous chemical reactions</a> and changes in the activity of genes happening all the time inside cells. </p>
<p>Some of these reactions happen in response to external signals, such as <a href="https://theconversation.com/how-scientists-are-helping-plants-get-the-most-out-of-photosynthesis-196226">changes in light</a>, temperature or nutrient availability. But many are part of each plant’s <a href="https://doi.org/10.1242/dev.117614">developmental programme</a>, encoded <a href="https://www.britannica.com/science/plant-development">in its genes</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
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<p>Some of these cell processes have <a href="https://www.sciencedirect.com/science/article/abs/pii/S0955067404001759?via%3Dihub">regular oscillations</a> – some families of molecules rhythmically appear and disappear every few hours. The most well known example is <a href="https://doi.org/10.1111/dgd.12242">circadian rhythms</a>, the internal clock in plants and animals (including humans).</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/how-understanding-plant-body-clocks-could-help-transform-how-food-is-grown-199137">How understanding plant body clocks could help transform how food is grown</a>
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<h2>Natural cycles</h2>
<p>There are many other examples of spontaneous oscillations in nature. Some are fast such as heart beats and the <a href="https://www.britannica.com/science/mitosis">mitotic cell cycle</a>, which is the cycle of cell divisions. Others, like the menstrual cycle <a href="https://www.britannica.com/science/hibernation">and hibernation</a>, are slow. </p>
<figure class="align-center ">
<img alt="Man holding plant root while transplanting the flower plant" src="https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568422/original/file-20240109-17-38gv4r.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">
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<span class="caption">There are intricate chemical processes happening inside those plant roots.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/focus-on-florist-man-hands-wearing-2190385311">Zamrznuti tonovi/Shutterstock</a></span>
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<p>Most often, they can be explained by an underlying <a href="https://swainlab.bio.ed.ac.uk/psb/lectures/negative.pdf">negative feedback loop</a>. This is where a process triggers a series of events which then represses the very activity it triggered. This seems to be the case for the root growth pulsation. </p>
<p>Shortly after the root tip gene oscillation was discovered, <a href="https://www.science.org/doi/10.1126/science.1191937">scientists noticed</a> this pulsation leaves an invisible mark. They found this out by using fluorescent markers visible under a microscope. These marks are left at places where the root can grow sideways. This means they provide regular cues that lead to the root system taking its shape.</p>
<p>Its cause is unknown today, although scientists have ruled out theories that it may be driven by circadian oscillations. </p>
<p>We do know there are many feedback loops involved. A plant hormone <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0291-0">called auxin</a> seems to be crucial to the process. It wakes up some genes coding for proteins, such as those needed for growth. Charles Darwin <a href="https://academic.oup.com/plphys/article/154/2/501/6108610">hypothesised the existence</a> of auxin and its chemical structure was confirmed <a href="https://cshperspectives.cshlp.org/content/2/10/a004572">around 100 years ago</a>. </p>
<p>The genes which oscillate are the auxin “targets”. When auxin enters a cell, these target genes tend to become more active. Some of these genes are related to growth but not all. Auxin triggers the removal of “repressors”, <a href="https://www.genome.gov/genetics-glossary/Repressor#:%7E:text=A%20repressor%2C%20as%20related%20to,of%20gene%20expression%20in%20cells.">proteins which can block</a> the activity in genes. Animals have repressors in their cells too. </p>
<p>But these repressors are activated by the genes they block. It could be that this feedback loop triggers the oscillations we see, but we don’t know for sure.</p>
<p>We know auxin moves from cell to cell via an intricate network of <a href="https://doi.org/10.1242/dev.079111">transporter proteins</a>. The way proteins direct travel to parts of cells depends on the surrounding levels of auxin itself. This is another feedback loop. The pulsation happens in growing roots, where cells at the tip are continually dividing as a result of the cell cycle (which involves separate feedback loops).</p>
<h2>What a conundrum</h2>
<p>Scientists often turn to mathematics to help explain things. Researchers have used geometry since ancient history to study the visible part of plants. A branch of mathematics developed in the 19th century called <a href="https://en.wikipedia.org/wiki/Dynamical_system">Dynamical Systems Theory</a> (DST), has given scientists some clarity about why plant roots oscillate. Scientists have been using tools from DST to try and show how <a href="https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1011646">auxin patterns</a> are affected by rounds of cell divisions.</p>
<p>If these rounds of cell division were well synchronised, we could show that, in theory, this would produce a regular pulse of auxin. </p>
<p>But this doesn’t solve the mystery because cells do not typically divide all at the same time, and so any pulsation of auxin would be fairly irregular. </p>
<p>When my team looked under the microscope for fluorescent auxin markers, we found a lack of regularity in auxin, in the parts of the root where its target genes oscillate regularly. </p>
<p>This suggests that the root tip gene oscillation may be linked to root growth but doesn’t happen at the same time as root stem cells are dividing. </p>
<p>Though still mysterious, we are now better equipped to decipher this enigma. The answer is probably not with one single process, but a result of an interplay between various processes. We know the key players, but the rules of the game they play are yet to be discovered. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/why-do-cauliflowers-look-so-odd-weve-cracked-the-maths-behind-their-fractal-shape-164121">Why do cauliflowers look so odd? We've cracked the maths behind their 'fractal' shape</a>
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<img src="https://counter.theconversation.com/content/220350/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Etienne Farcot 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>Scientists are still trying to puzzle out strange oscillations in plant root genes,Etienne Farcot, Associate professor of Mathematics, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2062812023-08-07T12:06:44Z2023-08-07T12:06:44ZSuccessfully managing forests must include stewarding the hidden life belowground<figure><img src="https://images.theconversation.com/files/531843/original/file-20230614-27-m8n5el.jpg?ixlib=rb-1.1.0&rect=3%2C0%2C1717%2C1092&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Forest-harvesting practices that retain living trees throughout the harvested area sustain belowground life.</span> <span class="attribution"><span class="source">(John L. Innes)</span>, <span class="license">Author provided</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/successfully-managing-forests-must-include-stewarding-the-hidden-life-belowground" width="100%" height="400"></iframe>
<p>Half of the biodiversity in forests is unseen because it lives belowground. These organisms are miniscule in size, but their importance to the ecosystem is enormous. </p>
<p>In a single teaspoon of forest soil there are <a href="https://doi.org/10.1038/nature13855">thousands of species</a> and billions of individual organisms. These include microorganisms such as bacteria and archaea, soil animals like the microscopic protozoa, nematodes, tardigrades, collembolan and mites, and larger fauna such as millipedes, centipedes and worms. </p>
<p>A cubic centimetre of forest soil can also harbour more than a kilometre of <a href="https://doi.org/10.1111/gcb.16073">fungal hyphae</a>, the mass of thread-like cords running through the soil and forming mycelia. </p>
<p>This astonishing diversity of belowground life is arranged into complex food webs, with many of the larger animals feeding on smaller animals and microorganisms. This complex network has been largely ignored in forest management, but could be a key ally in making our forests resilient to stresses imposed by global climate change. </p>
<h2>Life belowground</h2>
<p>All life belowground ultimately relies on plants for nourishment. Some soil organisms feed on dead leaves and roots, which they <a href="https://doi.org/10.1016/j.foreco.2021.119522">transform into soil organic matter</a>. This matter is critical for soil fertility and water retention, and is the primary reservoir for soil carbon.</p>
<p>Other belowground organisms rely on the <a href="https://doi.org/10.1016/j.soilbio.2012.02.001">simple sugars</a> released from the roots of living trees to survive and grow. In tree needles and leaves, atmospheric carbon dioxide is converted into sugars and other metabolites via photosynthesis. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1623745635546718208"}"></div></p>
<p>Up to half of the sugars produced in leaves are conveyed belowground to tree roots. A portion of these sugars are <a href="https://doi.org/10.1111/gcb.13850">exuded from root tips</a> or transferred to mycorrhizal fungi that live in and around the roots.</p>
<p>Mycorrhizal fungal hyphae extend from root tips further into the soil and also <a href="https://doi.org/10.3389/fmicb.2019.00168">exude sugars</a> and metabolites. These compounds support abundant <a href="https://doi.org/10.1016/j.soilbio.2003.10.015">soil microorganisms</a> and form the basis of a vast food web belowground. </p>
<p><a href="https://doi.org/10.1111/j.1469-8137.2007.02238.x">Within hours or days</a> of carbon dioxide being taken up by tree leaves, some of the carbon is released from roots and fungal hyphae and distributed throughout the <a href="https://doi.org/10.1002/rcm.6368">belowground food web</a>. </p>
<p>The <a href="https://doi.org/10.1016/j.soilbio.2020.107929">dead bodies</a> of, and metabolites released by, the soil microorganisms are also an important source of soil organic matter.</p>
<h2>Managing the whole forest</h2>
<p>This new appreciation of the importance of living roots in sustaining life belowground should prompt us to rethink forest management.</p>
<p>Harvesting trees severs the critical flow of resources belowground, directly reducing the abundance and diversity of soil life. However, harvesting practices that <a href="https://doi.org/10.1016/j.foreco.2023.120848">retain living trees</a> within 15 metres of each other, can maintain soil life throughout the harvested area. </p>
<p>Forest harvesting practices that retain a portion of the living trees, such as continuous cover forestry and <a href="https://doi.org/10.1111/1365-2664.12289">retention forestry</a> can help keep the soil alive in harvested forests.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A forest patch" src="https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541294/original/file-20230804-33657-ldda9c.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>
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<span class="caption">Retention forestry in a Douglas-fir forest on Vancouver Island, in which 40 mature living trees were retained per hectare.</span>
<span class="attribution"><a class="source" href="https://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/silviculture/silviculture-research/silvicultural-systems-research/stems/uniform-dispersed-retention">(Government of British Columbia)</a>, <span class="license">Author provided</span></span>
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</figure>
<p>Plant diversity also matters, as species differ in the variety of compounds released by their roots, which influences <a href="https://doi.org/10.1002/ece3.2454">microbial diversity</a> in the soil. </p>
<p>Soil biodiversity can be promoted by establishing forests with more than one tree species. In particular, forests that contain <a href="https://doi.org/10.1111/ele.13651">broadleaf tree species</a> and tree species with <a href="https://doi.org/10.1016/j.foreco.2020.118127">nitrogen-fixing</a> microbial associates promote soil biodiversity and replenishment of soil organic matter.</p>
<h2>Twenty-first century forestry</h2>
<p>In the face of the twin crises of climate change and biodiversity collapse, we need forests that are resilient and diverse. Soil organisms are critical allies in this endeavour.</p>
<p><a href="https://doi.org/10.1038/nature13855">Soil organisms</a> contribute half of the biodiversity of forests and regulate the processes that govern soil fertility, water retention and greenhouse gas emissions. Forestry practices that foster soil biodiversity can assist in making our forests resilient and diverse.</p>
<p>The vital role of inputs from living roots for sustaining soil organic matter and belowground life has been recognized in agriculture and is a central principle of <a href="https://doi.org/10.2489/jswc.2021.0920A">regenerative agriculture</a>, a suite of practices that actively restore soil quality, biodiversity, ecosystems health and water quality while producing sufficient food of high nutritional quality. </p>
<p>Forestry could also be regenerative, particularly if we apply practices such as continuous cover and species mixtures, and intentionally conserve life belowground.</p><img src="https://counter.theconversation.com/content/206281/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sue Grayston receives funding from Mitacs. </span></em></p><p class="fine-print"><em><span>Cindy Prescott does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The important role living roots play for sustaining life belowground should prompt us to rethink forest management.Cindy Prescott, Professor of Forest Ecology, University of British ColumbiaSue Grayston, Professor of Soil Microbial Ecology, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2009662023-04-17T16:09:39Z2023-04-17T16:09:39ZHow soils changed life on Earth<p>For the first 4 billion years of Earth’s existence, its continents were dusty, barren and rocky landscapes similar to the surface of Mars. But, around 500 million years ago, this all changed. </p>
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<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/how-soils-changed-life-on-earth-200966 &bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p><em>You can listen to more articles from The Conversation, narrated by Noa, <a href="https://theconversation.com/us/topics/audio-narrated-99682">here</a>.</em></p>
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<p>Land plants began to evolve from their freshwater algal ancestors and gradually covered the planet’s rocky surface. Originally just a few centimetres tall, the first land plants quickly evolved into more complex forms. By 385 million years ago, extensive forests covered the planet’s surface. </p>
<p>This new plant diversity was underpinned by a transition that occurred below the ground – the formation of roots and soils. Soils are so abundant today that we often take them for granted or assume they are a constant feature of our planet. But this is not the case. Deep soils as we know them have existed for <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/pala.12185">less than 10% of our planet’s history</a>. </p>
<p>The formation of these soils dramatically changed life on Earth. Soils altered terrestrial landscapes, water courses, nutrient and mineral cycling and even the composition of the atmosphere. The role soil played in making Earth habitable highlights the importance of protecting our soils today.</p>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
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<h2>The first soils</h2>
<p>The earliest evidence for how soils evolved comes from ancient land plant fossils. A rock formation in the northeast of Scotland, called the <a href="https://pubs.geoscienceworld.org/geolmag/article-abstract/157/1/47/581268/An-introduction-to-the-Rhynie-chertIntroduction-to">Rhynie Chert</a>, contains exceptionally well preserved 407 million-year-old plant fossils. This allows scientists to <a href="https://royalsocietypublishing.org/toc/rstb/2018/373/1739">study the diversity of life</a> that thrived here. </p>
<p>The majority of the plants preserved in the Rhynie chert lack the large complex roots typical of plants you may be familiar with today. Their rooting systems were instead composed of <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.2017.0042">thin stems that were covered by hairs called rhizoids</a>. These hairs helped anchor plants to the planet’s rocky surface and absorb water and nutrients. </p>
<figure class="align-center ">
<img alt="Artists reconstruction of rhizoid-based rooting systems from the Rhynie chert." src="https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=478&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=478&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=478&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=600&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=600&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516630/original/file-20230321-24-8ozpwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=600&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artists reconstruction of rhizoid-based rooting systems from the Rhynie chert, Aberdeenshire.</span>
<span class="attribution"><a class="source" href="https://royalsocietypublishing.org/doi/10.1098/rstb.2017.0042">Rosemary Wise/Royal Society Publishing</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>New hairy stems grew and intertwined with the mass of decaying older stems to gradually build up a thin peaty soil just a few centimetres thick. Despite its thinness, this soil could resist being blown or washed away, so provided a foothold for more plants to grow. </p>
<p>Early soils, like those preserved in the Rhynie chert, supported a diverse range of fungi. Some formed beneficial relationships with plants, helping them mine for nutrients in exchange for carbon provided by the plants – others fed on decaying plant tissue. </p>
<p>These soils also formed a hunting ground for <a href="https://www.britannica.com/animal/mite">mites</a>, <a href="https://www.britannica.com/animal/nematode">nematodes (roundworms)</a> and early arachnids. The plants, animals and fungi together formed a complex food web. </p>
<p>This thin soil was already teaming with life.</p>
<h2>Diversity of plants</h2>
<p>Skip forward 20 million years and Earth’s continents are covered by forests with <a href="https://www.sciencedirect.com/science/article/pii/S0960982219315696">soils over a metre deep</a>. This remarkable increase in soil depth, in what is considered a short space of geological time, was fuelled by the evolution of plant roots. Roots increase soil depth by growing downwards and adding organic matter deeper into the sediment.</p>
<p>Roots are specialised organs that enable plants to anchor and mine for water and nutrients. They are specially adapted for life below the ground and for pushing their way down into the rocky substrate below Earth’s surface.</p>
<p>The move from hairy stems clinging to the top of the rocky substrate to roots that drilled down over a metre in depth, transformed soils and allowed plants to access deep reserves of water and nutrients. This below-ground revolution provided an entirely new ecosystem for life to diversify into. </p>
<figure class="align-center ">
<img alt="Exposed modern tree roots." src="https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516636/original/file-20230321-1234-v5a9sw.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">Exposed modern tree roots, Sutherland, Scotland.</span>
<span class="attribution"><span class="source">Sandy Hetherington</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Soils changed more than what’s under our feet</h2>
<p>Soils are the key interface between geology, the atmosphere and the water and nutrient cycles. The advent of deep soils transformed the interaction between these parts of the Earth and brought about a number of surprising changes.</p>
<p>One change was to the water cycle. What was once a landscape covered in a large number of small crisscrossing streams was transformed into floodplains with large <a href="https://www.nature.com/articles/ngeo1376">meandering river channels</a>. At the same time, soils were storing water that could sustain more plant life and be cycled quickly back into the atmosphere.</p>
<p>The period in which soils were expanding in depth and extent was also accompanied by an <a href="https://www.sciencedirect.com/science/article/pii/S0012825217304117">enormous drop in atmospheric CO₂ levels</a> and cooling global temperatures. This change to the composition of the atmosphere was partly due to two features of roots and soils. </p>
<p>Plant roots helped to increase the weathering of rocks by physically and chemically breaking down bedrock – a process that results in a <a href="https://www.pnas.org/doi/full/10.1073/pnas.0408724102">net drawdown of CO₂ from the atmosphere</a>. </p>
<p>Soils, especially organic rich peat soils, are also huge carbon reservoirs. Plants require CO₂ to grow and when plants decay, CO₂ is released back to the atmosphere. But this plant material does not fully decay in many soils and much of it is gradually buried. </p>
<p>This locks carbon in peaty soils, which if buried, can form coal. The origin of deep soils and forests <a href="https://www.pnas.org/doi/10.1073/pnas.1517943113#:%7E:text=Rather%20than%20a%20consequence%20of,during%20the%20assembly%20of%20Pangea.">greatly increased carbon burial rates</a> on Earth.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An example of modern peaty soil." src="https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516640/original/file-20230321-28-n6814o.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">Modern peaty soil, Isle of Skye, Scotland.</span>
<span class="attribution"><span class="source">Sandy Hetherington</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Soil underpins a huge amount of life on Earth. Its role in the water cycle, nutrient cycle and critically as a reserve of carbon remain key today and in the future. The fossil record serves as a reminder that we must <a href="https://theconversation.com/soil-is-our-best-ally-in-the-fight-against-climate-change-but-were-fast-running-out-of-it-128166">protect our soils</a>.</p><img src="https://counter.theconversation.com/content/200966/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sandy Hetherington works for The University of Edinburgh, and his research is currently funded by a UKRI Future Leaders Fellowship.</span></em></p>What fossil records tell us about when the Earth was first covered by plants.Sandy Hetherington, Plant Evolutionary Biologist, The University of EdinburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2001402023-02-23T06:15:26Z2023-02-23T06:15:26ZSome houseplants take in nutrients from roots outside the soil – and it may change how we care for them<p>In recent years, we have seen growing interest in houseplants, particularly <a href="https://www.theguardian.com/lifeandstyle/2022/jan/16/how-youthful-plant-lovers-are-shaking-up-staid-old-horticultural-ways">among younger generations</a>. Between 2019 and 2022, houseplant sales in the UK <a href="https://gca.org.uk/garden-centres-saw-green-shoots-of-recovery-in-2021/">increased by more than 50%</a>. Indoor plants are associated with a range of <a href="https://theconversation.com/houseplants-dont-just-look-nice-they-can-also-give-your-mental-health-a-boost-186982">environmental and health benefits</a> including cleaner air, better mental health and clearer thinking.</p>
<p>If you’re a plant parent, you probably know that plants need food and water to grow and survive. You will also know that plants have roots for taking these resources in and leaves to absorb the light energy required for photosynthesis. This sounds simple, but many of us (including me) struggle to keep our plants healthy.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
<hr>
<p>Many common houseplants, especially those in the <a href="http://www.aroid.org/aroid/">aroid family</a> like the <a href="https://en.wikipedia.org/wiki/Monstera_deliciosa">monstera</a> (or the Swiss cheese plant) and <a href="https://en.wikipedia.org/wiki/Philodendron">philodendron</a> evolved in tough conditions. In their tropical or subtropical forest homes, these plants begin life on the ground but quickly climb the nearest tree to escape the dimly lit forest floor. They produce aerial roots that grow from stems above the ground and attach the plant to a tree’s trunk, allowing them to climb.</p>
<p>Knowing whether these roots take up nutrients or not will influence how we care for these plants. Currently, people tend to feed them in the soil with regular watering and plant food. So in a <a href="https://onlinelibrary.wiley.com/doi/10.1111/pce.14568">recent study</a>, my colleague and I compared aerial and soil-formed roots’ ability to take up nitrogen, an important plant food. </p>
<p>We expected the soil roots to better take up nitrogen because the soil is where the nutrients are – certainly in most houseplant potting mixes. Instead, we found that the aerial roots were far more efficient at taking up nitrogen than their soil counterparts.</p>
<h2>Reach for the sky</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A monstera plant growing up a neighbouring tree." src="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Monstera climb aerial roots to access lighter areas of the forest canopy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/monstera-plants-growing-heights-20-metres-788113741">Pomme Home/Shutterstock</a></span>
</figcaption>
</figure>
<p>As they climb, aroids grow more leaves. To sustain this growth, the plant will require more nutrients and water. Trees and shrubs effectively meet their demands for food and water by adding new pipes called xylem and phloem to the stem or roots. </p>
<p>The xylem is a tissue that transports water and nutrients upward, from the roots to the leaves. The phloem carries sugars the opposite way.</p>
<p>But monstera and philodendron (and other aroids) are instead related to grasses, meaning they are unable to make new pipes to take up resources. Without help, they would run out of suck – like trying to suck a thick milkshake through a small straw – leaving them unable to feed their increasing leaf area. </p>
<p>Monsteras and philodendrons overcome this problem by growing roots from the new stems as they grow (effectively adding more straws). These new roots grow downwards towards the soil where, in theory, they will take up nutrients and water. </p>
<p>But until now, this theory has not been tested.</p>
<h2>Caring for your plants</h2>
<p>We grew three common houseplants, a <a href="https://www.rhs.org.uk/plants/59193/philodendron-scandens/details">philodendron</a>, an <a href="https://www.gardenersworld.com/plants/anthurium-andreanum/">anthurium</a> (flamingo flower) and an <a href="https://www.rhs.org.uk/plants/32104/epipremnum-pinnatum-aureum/details">epipremnum</a> (devil’s ivy) both in humid conditions where there was plenty of water in the atmosphere, and in conditions typical of an office building (around 45% humidity).</p>
<p>After a few months, we recorded how big the plants were and then measured exactly how much nitrogen was taken up by each type of root. </p>
<p>Nitrogen uptake is measured by using a label – a bit like feeding flowers food dye. Nitrogen is present in nature in two “sizes”, called <a href="https://en.wikipedia.org/wiki/Isotopes_of_nitrogen">stable isotopes</a>. The heavy one, nitrogen-15, is far less abundant in nature than the lighter nitrogen-14, so when we fed the roots a solution high in the heavy nitrogen, we were able to measure how much of it was taken up compared to the other nitrogen isotope already in the roots. </p>
<p>To compare soil roots with aerial roots, we then fed the heavy nitrogen solution to individual roots and measured the amount of heavy nitrogen that was taken up by each. </p>
<p>Houseplants with more moisture in the air grew bigger and lost less water from their leaves during photosynthesis. In some situations, it was clear the plants were taking up water from their leaves.</p>
<p>Aerial roots were also much better at taking up nitrogen than soil roots. In anthurium and epipremnum, aerial roots took in up to 35% more nitrogen than the soil roots. </p>
<figure class="align-center ">
<img alt="A woman standing on a ladder tending to her houseplants." src="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Epipremnum’s aerial roots took in more nitrogen than the soil roots.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/focused-african-american-woman-tending-epipremnum-2244583755">DimaBerlin/Shutterstock</a></span>
</figcaption>
</figure>
<p>We are now exploring how and why this happens in more detail, but this could be because intense competition between neighbouring trees and shrubs in the plants’ original forest habitat strip soil of its nutrients. Being able to catch nutrients from decomposing leaf litter as they run down stems can thus be an advantage. The soil roots of some tropical trees even grow <a href="https://www.science.org/doi/10.1126/science.235.4792.1062">up the trunks</a> of neighbouring trees.</p>
<p>This suggests that we could be caring for these houseplants all wrong. We tend to ignore their aerial roots when all we need to do is give these roots a good spray with a liquid fertiliser. This will run down the aerial roots towards the stems and into the soil, making sure the soil roots are not neglected entirely.</p>
<p>Houseplants, particularly aroids, are a feature of many of our homes. But to fully experience their benefits, these indoor plants must be healthy. This may involve changing how we look after them.</p><img src="https://counter.theconversation.com/content/200140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Rasmussen does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research finds that some common houseplants take in nutrients from outside the soil.Amanda Rasmussen, Assistant Professor, Faculty of Science, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1964482023-01-06T06:07:49Z2023-01-06T06:07:49ZThe amazing system plants use to shape their roots and why it could help protect crops from climate change<figure><img src="https://images.theconversation.com/files/500971/original/file-20221214-24-r6fykb.jpg?ixlib=rb-1.1.0&rect=24%2C32%2C5385%2C3576&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/roots-451913170">lewan/Shutterstock</a></span></figcaption></figure><p>Plants have <a href="https://www.nature.com/articles/s41561-022-00995-2">colonised the vast majority</a> of the Earth’s surface. So what is the key to their success? </p>
<p>People often think of plants as simple, senseless life forms. They may live rooted in one place, but the more scientists learn about plants, <a href="https://www.science.org/content/article/wood-wide-web-underground-network-microbes-connects-trees-mapped-first-time">the more complex and responsive</a> we realise they are. They are excellent at adapting to local conditions. Plants are specialists, making the most of what is close by to where they germinate. </p>
<p>Learning about the intricacies of plant life is about more than inspiring wonder in people though. Studying plants is also about making sure <a href="https://climate.nasa.gov/news/3124/global-climate-change-impact-on-crops-expected-within-10-years-nasa-study-finds/">we can still grow crops</a> in the future as climate change makes our weather increasingly extreme. </p>
<p>Environmental signals shape the growth and development of plants. For example, many plants use <a href="https://warwick.ac.uk/fac/sci/lifesci/research/molecularcontrolflowering/publications/new_phytologist_tansley_review_jackson.pdf">day length as the cue</a> to trigger flowering. The hidden half of plants, the roots, also use signs from their surroundings to ensure their shape is optimised to forage for water and nutrients. </p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
<hr>
<p>Roots protect their plants from stresses such as drought by adapting their shape (branching to increase their surface area, for example) to find more water. But until recently, we didn’t understand how roots sense whether water is available in the surrounding soil.</p>
<p>Water is the most important molecule on Earth. Too much or too little can destroy an ecosystem. The devastating impact of climate change (as recently seen in Europe and east Africa) is making <a href="https://royalsociety.org/topics-policy/projects/climate-change-evidence-causes/question-13/">both floods and droughts more common</a>. Since climate change is <a href="https://www.c2es.org/content/drought-and-climate-change/">making rainfall patterns</a> increasingly erratic, learning how plants respond to water shortage is vital for making crops more resilient. </p>
<h2>Taking root</h2>
<p>Our team of plant and soil scientists and mathematicians <a href="https://www.science.org/doi/10.1126/science.add3771">recently discovered</a> how plant roots adapt their shape to maximise water uptake. Roots normally branch horizontally. But they pause branching when they lose contact with water (such as growing through an air-filled gap in the soil) and roots only resume branching once they reconnect with moist soil. </p>
<p>Our team found that plants use a system called <a href="https://www.sciencedirect.com/science/article/abs/pii/S1369526613000319">hydrosignalling</a> to manage where roots branch in response to water availability in the soil. </p>
<figure class="align-center ">
<img alt="Morning dew on spikelets of barley, young barley in the field bathed in dew and morning sunlight" src="https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501050/original/file-20221214-8754-cj9xs2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Barley uses hydrosignalling to form root structure.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/morning-dew-on-spikelets-barley-young-2119901924">Bildagentur Zoonar GmbH/Shutterstock</a></span>
</figcaption>
</figure>
<p>Hydrosignalling is the way plants sense where water is, not by measuring moisture levels directly but by sensing other soluble molecules that move with the water within plants. This is only possible because (unlike animal cells) plant cells are connected to one another <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/plasmodesmata#:%7E:text=Plasmodesmata%20are%20intercellular%20pores%20connecting,Burch%2DSmith%2C%202019">by small pores</a>. </p>
<p>These pores enable water and small soluble molecules (including hormones) to move together between root cells and tissues. When water is taken up by the plant root, it travels through the outermost epidermal cells. </p>
<p>The outer root cells also contain a <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0291-0#:%7E:text=Auxin%20is%20an%20essential%20molecule,are%20not%20yet%20fully%20understood.">hormone that promotes branching called auxin</a>. Water uptake triggers branching by mobilising auxin inwards to inner root tissues. When water is no longer available externally, say when a root grows through an air-filled gap, the root tip still needs water to grow. </p>
<p>So when roots can’t take in water from the soil they have to rely on water from their own veins deep inside the root. This changes the direction of water movement, making it now move outwards, which disrupts the flow of the branching hormone auxin.</p>
<p>The plant also makes an <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/abscisic-acid">anti-branching hormone called ABA</a> in its root veins. ABA moves with the flow of water too, in the opposite direction to auxin. So when the roots draw down on water from the plants’ veins, the roots are also drawing the anti-branching hormone towards themselves. </p>
<p>ABA stops root branching by closing all the small pores that connect root cells – a bit like blast doors on a ship. This seals off root cells from each other and stops auxin freely moving with water, blocking root branching. This simple system allows plant roots to fine tune their shape to local water conditions. It’s <a href="https://www.sciencedirect.com/science/article/pii/S0960982218310042">called xerobranching</a> (pronounced zerobranching). </p>
<h2>Flower power</h2>
<p>Our study also found that a plant’s roots use a similar system to reduce water loss as its shoots. <a href="https://kids.frontiersin.org/articles/10.3389/frym.2017.00058">Leaves stop water loss</a> during drought conditions by closing micro-pores called stomata on their surfaces. Stomata closure is also triggered by the ABA hormone. Similarly, in roots ABA reduces water loss by closing nano-pores called plasmodesmata that link every root cell together. </p>
<figure class="align-center ">
<img alt="microscopic image of stomata on leaves" src="https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501051/original/file-20221214-5220-2x2maj.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">
<figcaption>
<span class="caption">Leaf stomata under the microscope.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/leaf-stomata-under-microscope-1211487541">Barbol/Shutterstock</a></span>
</figcaption>
</figure>
<p>Roots from tomato, thale cress, maize, wheat and barley all respond to moisture in this way, despite evolving in different soils and climates. For example, <a href="https://sustainable-secure-food-blog.com/2020/09/22/the-tale-of-a-wild-tomatos-discovery/">tomatoes originated in a South American desert</a>, whereas <a href="https://www.inaturalist.org/guide_taxa/495156">thale cress</a> comes from central Asian temperate regions. This suggests xerobranching is a common trait in flowering plants, which are over 200 million years younger than <a href="https://theconversation.com/tree-ferns-are-older-than-dinosaurs-and-thats-not-even-the-most-interesting-thing-about-them-138435">non-flowering plants such as ferns</a>.</p>
<p>Roots from ferns, an early evolving land plant species, don’t respond to water in this way. Their roots grow more uniformly. This suggests flowering species are better at adapting to water stress than earlier land plants such as ferns. </p>
<p>Flowering plants can colonise a wider range of ecosystems and environments than non-flowering species. Given the rapid changes in rainfall patterns across the globe, the ability of plants to sense and adapt to a wide range of soil moisture conditions is more important now than ever.</p><img src="https://counter.theconversation.com/content/196448/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Bennett receives funding from UK Research Council BBSRC and hosts EU MCSA and EMBO fellow Poonam Mehra.</span></em></p><p class="fine-print"><em><span>Poonam Mehra receives funding from EMBO and Horizon 2020</span></em></p>A team of scientists unravelled the mystery of how plant roots make the most of soil moisture.Malcolm Bennett, Professor of Plant Sciences, University of NottinghamPoonam Mehra, Postdoctoral fellow in Biosciences, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1569322021-04-14T12:36:31Z2021-04-14T12:36:31ZPlants thrive in a complex world by communicating, sharing resources and transforming their environments<figure><img src="https://images.theconversation.com/files/394581/original/file-20210412-13-1rixjvo.jpg?ixlib=rb-1.1.0&rect=3%2C7%2C2392%2C1588&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Longleaf pines support one another through mycorrhizae – mutually beneficial relationships between certain fungi and the trees' roots.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/m4RFR2">Justin Meissen/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>As a species, humans are wired to collaborate. That’s why lockdowns and remote work have felt difficult for many of us during the COVID-19 pandemic. </p>
<p>For other living organisms, social distancing comes more naturally. I am a <a href="https://www.berondamontgomery.com/about-beronda/">plant scientist</a> and have spent years studying how light cues affect plants, from the very beginning of a plant’s life cycle – the germination of seeds – all the way through to leaf drop or death. In my new book, “<a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674241282">Lessons from Plants</a>,” I explore what we can learn from the environmental tuning of plant behaviors. </p>
<p>One key takeaway is that plants have the ability to develop interdependence, but also to avoid it when being connected could be damaging. Generally, plants are constantly communicating and engaged with other organisms in their ecosystems. But when these ongoing connections threaten to cause more harm than good, plants can exhibit a form of social distancing.</p>
<h2>The power of connection and interdependence</h2>
<p>When conditions are good, most plants are networkers. The <a href="https://www.motherearthnews.com/nature-and-environment/nature/symbiotic-relationship-zm0z14aszkin">vast majority of plants</a> have fungi that live on or within their roots. Together, the fungi and roots form structures known as <a href="https://hort.extension.wisc.edu/articles/mycorrhizae/">mycorrhizae</a>, which resemble a netlike web.</p>
<p>Mycorrhizae increase their host plants’ ability to absorb water and nutrients, such as nitrogen and phosphate, through their roots. In return, the plants share sugars that they produce through photosynthesis with their fungal partners. Thus, the fungi and host plants are powerfully interconnected, and depend on one another to survive and thrive. </p>
<p>Mycorrhizal connections can link multiple plants in a functioning network. When plants produce more sugars than they need, they can share them via this <a href="http://dx.doi.org/10.1126/science.aad6188">interconnected root-fungal network</a>. By doing so, they ensure that all plants in the community have access to the energy they need to support their growth.</p>
<p>Put another way, these connections extend beyond a single host plant and its fungal partner. They create communitywide relationships and interdependent networks of plants and fungi. Factors in the external environment, such as the amount of light available for photosynthesis and the composition of soil around the plants, fine-tune the connections in these networks.</p>
<p>Mycorrhizhae also serve as communication channels. Scientists have documented that plants <a href="https://doi.org/10.1093/aobpla/plv050">pass defensive chemicals</a>, such as substances that promote resistance against insect pests, to other plants via fungal networks. These connections also allow a plant that has been attacked by aphids or other such pests to signal to neighboring plants to <a href="https://doi.org/10.1111/ele.12115">preemptively activate their own defense responses</a>.</p>
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<figcaption><span class="caption">Mycorrhizhae are living communities of plant roots and fungi that benefit mutually from their relationship.</span></figcaption>
</figure>
<h2>When it’s safer to keep your distance</h2>
<p>Sharing resources or information that helps other plants ward off danger is a valuable example of the power of connectedness and interdependence in plant ecosystems. Sometimes, however, surviving requires plants to disconnect. </p>
<p>When environmental cues such as light or nutrients become scarce enough that a host plant can produce enough sugars through photosynthesis to support only its own growth, staying actively interconnected in a larger community network could be dangerous. Under such conditions, the host plant would lose more from sharing limited sugar supplies than it would gain from the network in water and nutrients. </p>
<p>At times like these, plants can <a href="https://doi.org/10.3389/fpls.2016.00782">limit mycorrhizal connections and development</a> by restricting how many materials they exchange with their fungal partners and avoiding making new connections. This is a form of physical distancing that protects the plants’ ability to support themselves when they have limited energy supplies so they can survive for the long term. </p>
<p>When conditions improve, plants can resume sharing with their fungal partners and establish additional connections and interdependence. Once again, they can benefit from sharing resources and information about the ecosystem with their extended plant and fungal communities. </p>
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<h2>Recognizing kin and collaboration</h2>
<p>Social distancing isn’t the only trick plants use to make their way in the world. They also recognize related plants and tune their abilities to share or compete accordingly. When the plants that are interconnected by a fungal network are close genetic relatives, they <a href="https://www.forestfloornarrative.com/blog/2017/9/7/plant-kin-recognition-and-mycorrhizae">share more sugars with the fungi in that network</a> than they do when the other plants are more distantly related.</p>
<p>Prioritizing kin may feel highly familiar to us. Humans, like other biological organisms, often actively contribute to help our kin survive. People sometimes speak of this as working to ensure that the “family name” will live on. For plants, <a href="http://dx.doi.org/10.3732/ajb.0900006">supporting relatives</a> is a way to ensure they carry on their genes. </p>
<p>Plants can also transform aspects of their environment to better support their growth. Sometimes essential nutrients that are present in soil are “locked up” in a form that plants can’t absorb: For example, iron can become bound up with other chemicals in forms very similar to rust. When this happens, plants can excrete compounds from their roots that essentially dissolve these nutrients into a form that the plants <a href="https://doi.org/10.1007/BF00008069">can readily use</a>. </p>
<p>Plants can transform their environments in this way either individually or collectively. Plant roots can grow in the same direction, in a collaborative process known as <a href="https://doi.org/10.1371/journal.pone.0029759">swarming</a> that is similar to bee swarms or bird flocks. Such swarming of roots enables the plants to release a lot of chemicals in a particular soil region, which frees up more nutrients for the plants’ use. </p>
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<figcaption><span class="caption">Trees use fungal networks to send one another messages – and some species hijack the system to sabotage their rivals.</span></figcaption>
</figure>
<h2>Better together</h2>
<p>Behaviors like mycorrhizal symbiosis, kin recognition and collaborative environmental transformation suggest that overall, plants are better together. By staying in tune with their external environment, plants can determine when working together and fostering interdependence is better than going it alone. </p>
<p>When I reflect on these tunable connections and interdependence between plants and fungi, I draw constant inspiration – especially during this pandemic year. As we make our way in a constantly changing world, plants offer all kinds of lessons for humans about independence, interdependence and supporting each other.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/156932/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beronda L. Montgomery receives funding from National Science Foundation, U.S. Department of Energy, and the MSU Foundation. </span></em></p>We may think of plants as passive life forms, but they can cooperate, share resources, send one another warnings, and distance themselves from their communities when survival depends on it.Beronda L. Montgomery, Professor of Biochemistry and Molecular Biology & Microbiology and Molecular Genetics; Interim Assistant Vice President of Research & Innovation, Michigan State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1531402021-01-14T19:00:23Z2021-01-14T19:00:23ZMutant roots reveal how we can grow crops in damaged soils<figure><img src="https://images.theconversation.com/files/378824/original/file-20210114-17-159e3mx.jpg?ixlib=rb-1.1.0&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/development-soybean-root-1248864754">Lidiane Miotto/Shutterstock</a></span></figcaption></figure><p>For years, conventional wisdom has held that roots don’t grow as deep in hard soil because it’s just too difficult for them to physically push through it. But our new research has unearthed another reason: their growth is controlled by a biological signal which can be “switched off”, enabling them to punch through compacted earth. It’s a discovery that could help crops to grow in even the most damaged of soils.</p>
<p>Soil compaction is <a href="https://research-repository.uwa.edu.au/en/publications/soil-compaction-in-cropping-systems-a-review-of-the-nature-causes">a major challenge facing modern agriculture</a>, driven in part by the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0016706103000971">increasing weight of farm equipment</a> which can pass over the same area of ground many times per season. Squashed under the weight of the soil above, deeper areas are also highly compacted, making it difficult for roots to <a href="https://www.sciencedirect.com/science/article/abs/pii/S0048969716316485?via%3Dihub">penetrate to those layers of earth rich in moisture and nutrients</a>. </p>
<p>The impact of this soil compaction is profound: because it <a href="https://academic.oup.com/jxb/article/70/21/6019/5554341">reduces root growth</a>, negatively impacting <a href="https://onlinelibrary.wiley.com/doi/full/10.1046/j.0016-8025.2001.00802.x">water and nutrient uptake</a>, soil compaction can cause yield losses of up to 25%. In the UK alone, losses associated with soil compaction are <a href="https://abdn.pure.elsevier.com/en/publications/mitigating-arable-soil-compaction-a-review-and-analysis-of-availa">estimated between €400 million (£355 million) and €650 million each year</a>.</p>
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<img alt="A tractor with wagon harvesting crops viewed from above" src="https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378820/original/file-20210114-13-14duhx7.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">
<figcaption>
<span class="caption">Heavy farming machinery contributes to the compaction of soils over time.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/jaguar-type-harvester-working-john-deere-505292872">Saverio blasi/Shutterstock</a></span>
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<p>Climate change is set to make these losses even greater. That’s because, when compaction is <a href="https://www.jstor.org/stable/42949486?seq=1">combined with drought</a>, crop yields can reduce by <a href="https://www.tandfonline.com/doi/abs/10.1626/pps.3.316">up to 75%</a>, which is estimated to cost farmers <a href="https://abdn.pure.elsevier.com/en/publications/mitigating-arable-soil-compaction-a-review-and-analysis-of-availa">billions of dollars</a> each year. As droughts become more common, developing crops resistant to these challenges becomes more important.</p>
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<strong>
Read more:
<a href="https://theconversation.com/two-thirds-of-earths-land-is-on-pace-to-lose-water-as-the-climate-warms-thats-a-problem-for-people-crops-and-forests-151984">Two-thirds of Earth's land is on pace to lose water as the climate warms – that's a problem for people, crops and forests</a>
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<p>Despite its clear importance for farmers across the world, the mechanism behind stunted root growth in compacted soil <a href="https://academic.oup.com/jxb/article/70/21/6019/5554341">has remained unclear</a>. Roots that failed to penetrate highly compacted soils were simply considered <a href="https://academic.oup.com/jxb/article/62/1/59/515854">too weak to do so</a>. However, we have discovered that roots are in fact able to penetrate highly compacted soil — after their sensitivity to a plant hormone signal is disrupted.</p>
<h2>Root breakthrough</h2>
<p><a href="https://science.sciencemag.org/cgi/doi/10.1126/science.abf3013">Our study</a> found that this signal or “switch” is controlled by a hormone called ethylene, which is released as a gas from the tips of plant roots. In loose, non-compacted soils, this gas is free to diffuse into the earth. But in hard, compacted soils, the ethylene gas cannot diffuse, and is instead trapped in the area occupied by the root tip — causing ethylene to build up in root tissues themselves. </p>
<p>This ethylene build-up, our study has found, prompts roots to stop growing longer in compacted soil. Ethylene therefore acts as a very clear “stop” signal to the extension of roots into compacted soils.</p>
<p>In our experiments, we used plants with a specific genetic mutation that left them no longer able to sense ethylene signals. We found that roots do have the ability to penetrate compacted soil, but elect not to when presented with the ethylene-based stop signal. </p>
<p>We deliberately performed our studies using two very different types of soil (sand and clay) and two very different species of plant: rice and <em>Arabidopsis</em> (a close relative of oil seed rape). The fact that we observed the same behaviour in different soils and plants suggests that our findings may be widely applicable to other crops, soil types and geographies.</p>
<figure class="align-center ">
<img alt="Yellow wheat plants grow above cracked dry soil" src="https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378822/original/file-20210114-22-1skm6z1.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">
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<span class="caption">Plants with deeper root systems are more resilient to droughts.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wheat-crops-suffer-drought-continues-field-1145270459">Jasper Suijten/Shutterstock</a></span>
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<p>Our findings open up new opportunities to select new, compaction-resistant crops — just as <a href="https://www.jic.ac.uk/research-impact/molecules-from-nature/impact/peas/the-history-of-pea-research-at-the-john-innes-centre/gregor-mendel-the-father-of-genetics/">Gregor Mendel, “the father of genetics”, first selectively bred different varieties of peas</a>. Breeders can now simply screen their collections for varieties whose roots are less sensitive to ethylene, choosing to create new plants with this differentiation.</p>
<p>However, as this hormone signal is also important for other plant processes like resistance to pathogens, more targeted gene editing and genetic modification (GM) approaches could also be adopted to only block the ethylene response in root tip tissues, rather than the plant as a whole. Time will tell which of these distinct approaches will prove the most effective.</p>
<h2>Boosting agriculture</h2>
<p>Our findings have the potential to lead to protected or increased crop yields worldwide, especially given that soil compaction remains a persistent problem in intensive agriculture practices. <a href="https://publications.jrc.ec.europa.eu/repository/bitstream/JRC68418/lbna25186enn.pdf">In Europe alone</a>, 36 million hectares (out of a total of 68 million hectares) of farmed land is <a href="https://ec.europa.eu/environment/archives/soil/pdf/vol5.pdf">prone to soil compaction</a>.</p>
<p>Crops with roots that can penetrate deeper into this compacted soil will offer a number of obvious benefits. First, crop roots will be able to access sources of nutrients in deeper soil layers which are currently unavailable to them. That will in turn support the growth of larger, healthier crops.</p>
<p>Second, crop varieties that have more extensive root systems will be able to secure more reliable water sources, conferring greater resilience during periods of drought stress, which are set to increase with climate change. Finally, <a href="https://newatlas.com/gene-editing-plants-deep-roots-climate/60582/">modelling suggests</a> that crops with deeper roots bury more carbon in the soil, aiding efforts to sequester carbon from the Earth’s atmosphere to limit climate change.</p>
<p>Our new understanding of how roots penetrate hard soils could be an important step towards breeding new types of crops that could be more resilient to soil compaction. Such crops, we expect, will help to reduce the yield losses associated with major soil stress and damage in various geographies across the world.</p><img src="https://counter.theconversation.com/content/153140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Bennett receives funding from Biotechnology and Biological Sciences Research Council (BB/G023972/1, BB/R013748/1, BB/L026848/1, BB/M018431/1, BB/PO16855/1, BB/M001806/1, BB/M012212, and BB/P016855/1); ERC FUTUREROOTS Advanced grant 294729; Future-Food Beacon and Challenge Grant–Royal Society (CHG\R1\170040).</span></em></p><p class="fine-print"><em><span>Bipin Pandey receives funding from Challenge Grant–
Royal Society (CHG\R1\170040) and Future-Food Beacon, University Of Nottingham. </span></em></p><p class="fine-print"><em><span>Sacha Mooney receives funding from BBSRC Designing Future Wheat Cross-Institute Strategic Programme BB/P016855/1 and LegumeSELECT. BB/R020590/1. </span></em></p>Researchers have unearthed a ‘biological switch’ which could boost crop yield worldwide.Malcolm Bennett, Professor of Plant Sciences, University of NottinghamBipin Pandey, Research scientist, School of Biosciences, University of NottinghamSacha Mooney, Professor in Soil Physics and Director of the Hounsfield Facility at the University of Nottingham, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1408622020-06-23T14:13:05Z2020-06-23T14:13:05ZCan roots tourism build social justice? A case study of travellers to Ghana provides insights<figure><img src="https://images.theconversation.com/files/343243/original/file-20200622-55005-ty08tc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The view from the dungeon of the Cape Coast Castle.</span> <span class="attribution"><span class="source">Alana Dillette</span></span></figcaption></figure><p>Protests against racism have erupted around the globe in recent weeks, sparked by the <a href="https://theconversation.com/the-fury-in-us-cities-is-rooted-in-a-long-history-of-racist-policing-violence-and-inequality-139752">murder</a> of a black man, George Floyd, at the hands of a white police officer in Minnesota, in the United States. This act of racial violence serves as a timely reminder of the racial inequalities that persist for black people around the world, African diasporas being no exception. </p>
<p>In fact, Ghana, which has been a leader in connecting this diaspora to its African roots through tourism, commemorated the life of Floyd with a <a href="https://www.graphic.com.gh/news/general-news/ghana-holds-memorial-service-for-george-floyd.html">memorial</a> service in Accra. The service was arranged by Ghana’s Year of Return committee, in partnership with the African Union of Diasporan Forum.</p>
<p>The <a href="https://www.un.org/africarenewal/magazine/december-2018-march-2019/2019-year-return-african-diaspora">Year of Return</a> – 2019 – was a tourism campaign to commemorate the 400th anniversary of the first slave ship landing in America. It was an instance of “<a href="https://www.tandfonline.com/doi/full/10.1080/09669582.2020.1727913">roots tourism</a>”, which appeals to travellers to visit a destination on the basis of their ancestry. </p>
<p>Beyond the education and personal transformation that many travellers gain from this type of tourism, could it also be an opportunity for racial reconciliation? </p>
<p>My <a href="https://www.tandfonline.com/doi/abs/10.1080/09669582.2020.1727913">study</a> of one recent group of African American roots travellers to Ghana suggests this may be a possibility. The study explored how the trip affected these travellers’ sense of identity and their commitment towards social justice initiatives. </p>
<h2>Exploring roots in Ghana</h2>
<p>In August 2018, I joined a group of 10 African American travellers on a 10-day trip to Ghana where we visited historical sights, as well as cities, villages and nature preserves. I interviewed the travellers before and after the trip, in addition to conducting observations and a focus group during the trip. I asked them about their expectations of the journey and how the experience had affected their identity. I also asked if it made them more likely to participate in social justice activities such as protesting, getting involved with social justice organisations in their communities and speaking up about social injustices in their professions. </p>
<p>Travellers revealed to me that the trip helped them to conceptualise slavery differently, and this led them to a deeper understanding of race relations in the United States. For example, one traveller said that prior to visiting Ghana, they felt a “certain anger towards white people”. But visiting Ghana and specifically the Cape Coast dungeon exposed them to learning more about all of the actors in slavery – (white) Europeans and (black) Africans. </p>
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Read more:
<a href="https://theconversation.com/ghana-hopes-year-of-return-will-boost-tourism-but-caution-is-needed-120338">Ghana hopes 'Year of Return' will boost tourism. But caution is needed</a>
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<p>Travellers also shared how the trip helped them to understand more deeply their identity as both African and American. For example, one participant said: </p>
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<p>I have these identifiable characteristics about me that link me to this place. I hope to go home and be able to exude that like a light off me, without being afraid or ashamed; we shouldn’t be fearful of who we really are.</p>
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<p>This quote exemplifies how identity formation through roots travel can lead to a form of reconciliation within travellers themselves. </p>
<p>Another traveller said they realised after the trip that roots tourism, if curated well, could be an avenue for cross-racial communication and understanding. They said they had noticed a clear difference between white and black tour groups at the Cape Coast dungeon. One was more romanticised, and one highlighted more of the horrific details of slavery. </p>
<p>This traveller said the romanticised experience was common at many former slave plantation heritage tourism sites in the US. These types of narratives only perpetuate experiences reminiscent of the <a href="https://nmaahc.si.edu/blog-post/traveling-through-jim-crow-america#:%7E:text=During%20the%20segregation%20era%2C%20discriminatory,food%2C%20restrooms%2C%20and%20lodging">Jim Crow</a> era. But if transformed, these experiences both in Ghana and the US could act as a platform for racial reconciliation. </p>
<p>One traveller described their own internal racial reconciliation by saying:</p>
<blockquote>
<p>We are all human. I wish that we lived in a world that could really and truly embrace that, but we don’t. So, for now, I continue trying to spread the love and be unashamed about who I am, which is a mixture of so many things, some of which do originate in Africa, and I am proud of that now. </p>
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<h2>Making peace</h2>
<p>These types of experiences through roots tourism represent an opportunity for the creation of peace and reconciliation. Travellers can learn together about the collective emotional trauma resultant from slavery, the misinformation that is often passed down about slavery and how these issues can be discussed openly. </p>
<p>Travel and tourism are not often linked to social justice. But the <a href="https://www.tandfonline.com/doi/full/10.1080/09669582.2020.1727913">research</a> shows that tourism does in fact provide a platform for this. Travellers in my study said their trip to Ghana empowered them to make changes towards social equity in their professional and personal lives. They described actionable change along with expanded mindsets. For example, one traveller mentioned getting involved with empowering black musicians in their community. Another started contributing financially to empower female business owners in Ghana. </p>
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<strong>
Read more:
<a href="https://theconversation.com/ghanas-year-of-return-2019-traveler-tourist-or-pilgrim-121891">Ghana's Year of Return 2019: traveler, tourist or pilgrim?</a>
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<p>Roots travel experiences also shine a light on the continued everyday racism that people face as a trickle-down effect of slavery. Participants described how societal racism in the US had made an impact on their lives, and how travelling to Ghana had emboldened them to search for clarity of identity and self, as well as social equality.</p>
<p>The research already shows that tourism can promote peace, transformation and cross-cultural understanding. But it’s a good time to ask how the travel and tourism industry has contributed to racism and how that can <a href="https://www.tourismreset.com/">change</a>.</p><img src="https://counter.theconversation.com/content/140862/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alana Dillette does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It is a good time to ask how the travel and tourism industry has contributed to racism and how that can change.Alana Dillette, Assistant Professor. L. Robert Payne School of Hospitality and Tourism Management, Tourism RESET, San Diego State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/735682017-03-01T10:47:01Z2017-03-01T10:47:01ZThe real horrors of the transatlantic slave trade behind Taboo and Roots<figure><img src="https://images.theconversation.com/files/158890/original/image-20170301-5494-234iig.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Trapped on the slave ship Cornwallis.</span> <span class="attribution"><span class="source">Scott Free Prods/Robert Viglasky/BBC</span></span></figcaption></figure><p>As James Delaney, the protagonist of the BBC’s <a href="https://theconversation.com/taboo-the-east-india-company-and-the-true-horrors-of-empire-73616">hit drama Taboo</a>, struggles with a vast assortment of enemies upon his return to London from Africa in 1814, he murmurs to his half-sister and former lover: “I have sailed to places where there is no damnation.” Although it is never clear whether he was referring to actual physical places or to some corners of his mind, it is clear that Africa – and the African slave trade – loom large in virtually every aspect of this renegade’s life. </p>
<p>Delaney’s haunting memories and visions relating to his involvement in the abominable commerce of human beings, means that the slave trade is almost permanently in the background as a running subplot that determines much of the subsequent action, as Delaney takes on the powerful East India Company, the British crown and America. </p>
<p>The story is set at a crucial historical moment, just seven years after the British parliament <a href="http://www.parliament.uk/slavetrade">abolished the transatlantic slave trade</a> and just as the British government was starting to put pressure on all European slave-trading nations at the <a href="https://www.parliament.uk/business/committees/committees-a-z/commons-select/petitions-committee/petition-of-the-month/the-congress-of-vienna-and-the-abolition-of-slavery/">Congress of Vienna</a> to end this inhumane traffic. </p>
<p>It is ironic, then, that the horror stories possessing Delaney’s mind in this fictional series, rather than disappearing, increased in number and frequency in the real world during the next few decades. This was especially the case after 1820, when the <a href="http://www.bbc.co.uk/history/british/abolition/royal_navy_article_01.shtml">British navy began policing the Atlantic</a> and courts of Mixed Commission and Vice-Admiralty began adjudicating vessels engaged in this now illegal activity. </p>
<h2>Horror stories</h2>
<p>The sloop Cornwallis, the fictitious vessel that haunts Delaney’s nightmares, appears to have run aground during a storm leaving the enslaved Africans to die in its hold. In the real slave trade, even if the storm could have been avoided, a combination of overcrowding, lack of drinkable water, a bad diet, deadly diseases, and maltreatment would often have led to a similar outcome. There are plenty of actual documented cases like this over the next few decades, as slave traders were forced to conduct their activities in the shadows and as the few controls put in place to improve conditions on board slave vessels in the 1790s were abandoned. </p>
<p>For example, in 1837, <a href="https://aha.confex.com/aha/2016/webprogram/Paper19619.html">the Arrogante</a>, a brig owned by the commercial house of Pedro Martinez & Co., based in Havana, gained sudden notoriety after being detained by a British cruiser and taken to Jamaica. There, a large number of the Africans who had been transported inside the vessel’s bowels, accused the crew of murdering one of the Africans, of eating his heart and liver, and then of slicing the man’s legs and arms into small square pieces and serving them with rice to the rest of the Africans. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158764/original/image-20170228-29917-1500hc2.jpg?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"></a>
<figcaption>
<span class="caption">Anatomy of a slave ship.</span>
<span class="attribution"><span class="source">ushistoryharwood.pbworks.com</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Only four years later, a small Canary Islands coaster, <a href="https://books.google.co.uk/books?id=oBQ6srSuwowC&pg=PA228&lpg=PA228&dq=the+Jesus+Maria+slaver&source=bl&ots=5v1FKY2J0Q&sig=O1OMPXfxY6vOUrZEbVcnPyJdNx8&hl=en&sa=X&ved=0ahUKEwi3ltm4j7PSAhUZM8AKHQOuD6AQ6AEIHjAC#v=onepage&q=the%20Jesus%20Maria%20slaver&f=false">the Jesus Maria</a>, was seized with more than 270 Africans crammed below deck in the most terrible conditions imaginable. Allegations of beatings, rapes and murders were soon to follow. Seasoned British officers who observed the conditions in which this group of men, women, and especially children arrived in Cuba in 1841, were left struggling for words to describe what they considered to be one of the cruellest cases of human trafficking they had ever witnessed.</p>
<h2>Out of Africa</h2>
<p>The accusations of unspeakable actions directed at Delaney in Taboo, including those of cannibalism, are not, therefore, totally out of order. Between 1820 and 1867 – the year of the last recorded transatlantic slave trade voyage, according to the the slave trade history site <a href="http://slavevoyages.org/">Voyages</a> – copious and detailed references exist to brutal actions like those carried out by Delaney, or the sailors of the Arrogante and the Jesus Maria. As a matter of fact, the BBC is also currently treating us to a remake version of the classic TV series Roots, based on Alex Haley’s eponymous novel, where the horrors of the slave trade are also presented in vivid and violent detail.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158763/original/image-20170228-29906-g4rm1t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Roots: a traumatic portrayal of the horrors of the slave trade.</span>
<span class="attribution"><span class="source">BBC/A+E</span></span>
</figcaption>
</figure>
<p>To be sure, after 1820, enslaved Africans were also forced to endure deadly diseases, piratical attacks, shipwrecks, longer voyages in always-overcrowded vessels, and hurried landings, usually at night and on locations that were hardly ideal for walking barefoot. This is perhaps Taboo’s only weak link in taking on the transatlantic slave trade: the experiences of Africans, beyond some spellbinding graphic images, are not explored in anywhere near the same depth as those of Delaney. </p>
<p>As a result, we can only continue to imagine the sort of memories and visions that may have haunted each and every one of them, from the moment they were seized in their homelands and marched in shackles towards the Atlantic coast, to the hour at which their eyes were closed forever.</p>
<p>When it comes to depicting the horrors of the slave trade, Taboo has done much better than most. Delaney’s own survival, his ghastly memories and visions, and even the beads and iron chains he finds aboard the Spanish brig he buys in a public auction, are manifest markers of a world where colonialism and modern capitalism were concocted – a world that was the result of profiting from human enslavement, displacement, suffering and death.</p><img src="https://counter.theconversation.com/content/73568/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Manuel Barcia has received funding from the British Academy, the Leverhulme Trust. He was the recipient of an Overseas Research Scholarship and a British Chevening Scholarship.</span></em></p>The television dramas have not exaggerated the horrors of the slave trade. The reality was often even worse for Africans taken from their homes.Manuel Barcia, Professor of Latin American History, University of LeedsLicensed as Creative Commons – attribution, no derivatives.