tag:theconversation.com,2011:/ca/topics/monoculture-19091/articlesMonoculture – The Conversation2023-08-07T12:44:10Ztag:theconversation.com,2011:article/2031082023-08-07T12:44:10Z2023-08-07T12:44:10ZComputer science can help farmers explore alternative crops and sustainable farming methods<figure><img src="https://images.theconversation.com/files/540847/original/file-20230802-23327-tn8hq8.jpg?ixlib=rb-1.1.0&rect=19%2C4%2C3176%2C2122&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chick peas intercropped with flax on a farm in Stanford, Mont.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/2hKjCG2">USDA NRCS Montana</a></span></figcaption></figure><p>Humans have physically reconfigured <a href="https://ourworldindata.org/land-use">half of the world’s land</a> to grow just eight staple crops: maize (corn), soy, wheat, rice, cassava, sorghum, sweet potato and potato. They account for the vast majority of calories that people around the world consume. As global population rises, there’s pressure to <a href="https://www.theguardian.com/global-development/2022/nov/15/can-the-world-feed-8bn-people-sustainably">expand production even further</a>.</p>
<p>Many experts argue that further expanding modern industrialized agriculture – which relies heavily on synthetic fertilizer, chemical pesticides and high-yield seeds – <a href="https://research.wri.org/wrr-food">isn’t the right way</a> to <a href="https://www.unep.org/news-and-stories/story/10-things-you-should-know-about-industrial-farming">feed a growing world population</a>. In their view, this approach <a href="https://theconversation.com/us-agriculture-needs-a-21st-century-new-deal-112757">isn’t sustainable ecologically or economically</a>, and farmers and scientists alike <a href="https://theconversation.com/regenerative-agriculture-can-make-farmers-stewards-of-the-land-again-110570">feel trapped</a> within this system. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/i6teBcfKpik?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Corn’s evolution into a global commodity shows how industrialized agriculture has transformed farming.</span></figcaption>
</figure>
<p>How can societies develop a food system that meets their needs and is also more healthy and diverse? It has proved hard to scale up alternative methods, such as organic farming, as broadly as industrial agriculture.</p>
<p>In a recent study, we considered this problem from our perspectives as a <a href="https://scholar.google.com/citations?user=Ikz6_Y0AAAAJ&hl=en">computer scientist</a> and a <a href="https://scholar.google.ca/citations?user=cJQv8WsAAAAJ&hl=en">crop scientist</a>. We and our colleagues <a href="https://scholar.google.com/citations?user=O7xJ4mcAAAAJ&hl=en">Bryan Runck</a>, <a href="https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=%22adam+streed%22&btnG=">Adam Streed</a>, <a href="https://scholar.google.com/citations?user=wDtsUmUAAAAJ&hl=en">Diane R. Wang</a> and <a href="https://scholar.google.com/citations?user=ukiVGLsAAAAJ&hl=en">Patrick M. Ewing</a> proposed a way to rethink <a href="https://doi.org/10.1093/pnasnexus/pgad084">how agricultural systems are designed and implemented</a>, using a central idea from computer science - abstraction - that summarizes data and concepts and organizes them computationally, so we can analyze and act upon them without having to constantly examine their internal details.</p>
<h2>Big output, big impacts</h2>
<p>Modern agriculture intensified over just a few decades in the mid-20th century – a blink of an eye in human history. <a href="https://doi.org/10.1073/pnas.0912953109">Technological improvements</a> led the way, including the development of <a href="https://www.britannica.com/technology/Haber-Bosch-process">synthetic fertilizer</a> and statistical methods that improved plant breeding. </p>
<p>These advances made it possible for farms to produce much larger quantities of food, but at the expense of the environment. Large-scale agriculture has <a href="https://www.ipcc.ch/site/assets/uploads/sites/4/2020/02/SPM_Updated-Jan20.pdf">helped drive climate change</a>, polluted lakes and bays with <a href="https://theconversation.com/to-reduce-harmful-algal-blooms-and-dead-zones-the-us-needs-a-national-strategy-for-regulating-farm-pollution-186286">nutrient runoff</a> and <a href="https://www.unep.org/news-and-stories/press-release/our-global-food-system-primary-driver-biodiversity-loss">accelerated species losses</a> by turning natural landscapes into monoculture crop fields.</p>
<p>Many U.S. farmers and agricultural researchers would like to grow a wider range of crops and use more sustainable farming methods. But it’s hard for them to figure out what new systems could perform well, especially in a changing climate. Lower-impact farming systems often require deep local knowledge, plus an encyclopedic understanding of plants, weather and climate modeling, geology and more. </p>
<p>That’s where our new approach comes in.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A field of soybean plants, half harvested, stretches to the horizon." src="https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540871/original/file-20230802-26048-ybmbaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Monoculture farming, like this Iowa soybean field shown during harvest, has contributed to the decline of bees and other pollinators by reducing their food sources.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-aerial-view-from-a-drone-shows-soybean-field-as-it-is-news-photo/1181120200">Joe Raedle/Getty Images</a></span>
</figcaption>
</figure>
<h2>Farms as state spaces</h2>
<p>When computer scientists think about complex problems, they often use a concept called a <a href="https://en.wikipedia.org/wiki/State_space_(computer_science)">state space</a>. This approach mathematically represents all of the possible ways in which a system can be configured. Moving through the space entails making choices, and those choices change the state of the system, for better or worse.</p>
<p>As an example, consider a game of chess with a board and two players. Each configuration of the board at a moment in time is a single state of the game. When a player makes a move, it shifts the game to another state.</p>
<p>The whole game can be described by its “state space” – all possible states the game could be in through valid moves the players make. During the game, each player is searching for states that are better for them.</p>
<p>We can think of an agricultural system as a state space in a particular ecosystem. A farm and its layout of plant species at any moment in time represent one state in that state space. The farmer is searching for better states and trying to avoid bad ones.</p>
<p>Both humans and nature shift the farm from one state to another. On any given day, the farmer might do a dozen different things on the land, such as tilling, planting, weeding, harvesting or adding fertilizer. Nature causes minor state transitions, such as plants growing and rain falling, and much more dramatic state transitions during natural disasters such as floods or wildfires. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-NZIvvhGlR0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Climate change is altering the zones in which major crops like corn and wheat can be grown, reducing yields in some cases and increasing them in others.</span></figcaption>
</figure>
<h2>Finding synergies</h2>
<p>Viewing an agricultural system as a state space makes it possible to broaden choices for farmers beyond the limited options today’s farming systems offer. </p>
<p>Individual farmers don’t have the time or ability to do trial and error for years on their land. But a computing system can draw on agricultural knowledge from many different environments and schools of thought to play a metaphorical chess game with nature that helps farmers identify the best options for their land. </p>
<p>Conventional agriculture limits farmers to a few choices of plant species, farming methods and inputs. Our framework makes it possible to consider higher-level strategies, such as growing multiple crops together or finding management techniques that are best suited to a particular piece of land. Users can search the state space to consider what mix of methods, species and locales could achieve those goals. </p>
<p>For example, if a scientist wants to test five crop rotations – raising planned sequences of crops on the same fields – that each last four years, growing seven plant species, that represents 721 potential rotations. Our approach could use information from <a href="https://doi.org/10.1093/biosci/biac021">long-term ecological research</a> to help find the best potential systems to test. </p>
<p>One area where we see great potential is <a href="https://agclass.nal.usda.gov/vocabularies/nalt/concept?uri=https://lod.nal.usda.gov/nalt/6581">intercropping</a> – growing different plants in a mixture or close together. Many combinations of specific plants have long been known to grow well together, with each plant helping the others in some way.</p>
<p>The most familiar example is the “three sisters” – maize, squash and beans – developed by <a href="https://www.nal.usda.gov/collections/stories/three-sisters">Indigenous farmers of the Americas</a>. Corn stalks act as trellises for climbing bean vines, while squash leaves shade the ground, keeping it moist and preventing weeds from sprouting. Bacteria on the bean plants’ roots provide nitrogen, an essential nutrient, to all three plants.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/reel/ChpP-J7DkXG/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>Cultures throughout human history have had their own favored intercropping systems with similar synergies, such as <a href="https://doi.org/10.1002/9781119521082.ch3">tumeric and mango</a> or <a href="https://doi.org/10.1016/j.agee.2020.107175">millet, cowpea and ziziphus, commonly known as red date</a>. And new work on <a href="https://theconversation.com/how-shading-crops-with-solar-panels-can-improve-farming-lower-food-costs-and-reduce-emissions-202094">agrivoltaics</a> shows that combining solar panels and farming can work surprisingly well: The panels partially shade crops that grow underneath them, and farmers earn extra income by producing renewable energy on their land. </p>
<h2>Modeling alternative farm strategies</h2>
<p>We are working to turn our framework into software that people can use to model agriculture as state spaces. The goal is to enable users to consider alternative designs based upon their intuition, minimizing the costly trial and error that’s now required to test out new ideas in farming. </p>
<p>Today’s approaches largely model and pursue optimizations of existing, often unsustainable systems of agriculture. Our framework enables discovery of new systems of agriculture and then optimization within those new systems.</p>
<p>Users also will be able to specify their objectives to an artificial intelligence-based agent that can perform a search of the farm state space, just as it might search the state space of a chessboard to pick winning moves. </p>
<p>Modern societies have access to many more plant species and much more information about how different species and environments interact than they did a century ago. In our view, agricultural systems aren’t doing enough to leverage all that knowledge. Combining it computationally could help make agriculture more productive, healthy and sustainable in a rapidly changing world.</p><img src="https://counter.theconversation.com/content/203108/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Barath Raghavan receives funding from the National Science Foundation, the Schmidt Family Foundation and Cisco Systems. </span></em></p><p class="fine-print"><em><span>Michael Kantar receives funding from the U.S. Department of Agriculture and the National Science Foundation. </span></em></p>Conventional agriculture offers farmers few choices about which crops to grow or how to raise them. A new approach uses computing to construct better strategies with lower environmental impacts.Barath Raghavan, Associate Professor of Computer Science and Electrical and Computer Engineering, University of Southern CaliforniaMichael Kantar, Associate Professor of Tropical Plants & Soil Sciences, University of HawaiiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2076562023-07-05T14:51:19Z2023-07-05T14:51:19ZWhy there are fewer insects on UK farms than there were a century ago – and how to restore them<figure><img src="https://images.theconversation.com/files/535516/original/file-20230704-23-jom9rr.jpg?ixlib=rb-1.1.0&rect=572%2C0%2C2415%2C1405&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Farmed landscapes have become less hospitable habitats for insects.
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/agricultural-plowed-field-ploughing-arable-land-775349260">Protasov AN/Shutterstock</a></span></figcaption></figure><p>Insect populations are declining worldwide at a rate of <a href="https://www.science.org/doi/10.1126/science.aax9931">almost 1% per year</a>. This decline is alarming. Insects play a crucial role in pollinating crops, controlling crop pests and maintaining soil fertility.</p>
<p>In the UK alone, pollination provided by bees and other insects adds <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.13755">over £600 million</a> to crop production every year. That’s about 10% of the country’s total annual crop value. </p>
<p>Through pollination, insects also make sure that fruit and vegetables are packed full of the vitamins and minerals needed for <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP10947">healthy human diets</a>. Insufficient pollination would result in lower-quality foods, less choice and higher food prices.</p>
<p>The decline of pollinating insects is already <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2445">affecting crop yields</a> in the UK. <a href="https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/eap.2743">Research</a> on 20 UK apple orchards found that a lack of pollination led to average yield deficits (where the maximum potential output of these orchards was not reached) of up to 22%.</p>
<p>The issue extends beyond the UK’s borders. The UK imports a substantial proportion of fresh produce from regions such as Europe, north Africa, South America and Asia. So the global decline of pollinating insects also poses a <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1002/pan3.10314">huge threat</a> to food security in the UK.</p>
<p>Just like fertiliser and water, these insects should be considered a legitimate agricultural input that needs to be protected and managed sustainably. There are effective methods available to restore beneficial insects to farmland, such as planting hedgerows and using pesticides sparingly, and farming practices are gradually changing. However, the implementation of these methods in the UK falls short of what is required to ensure the country’s food and nutritional security. </p>
<figure class="align-center ">
<img alt="A bumblebee collecting pollen and nectar from an apple tree flower." src="https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/535741/original/file-20230705-24-psf5g3.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">A bumblebee collecting pollen and nectar from an apple tree flower.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bumblebee-fluttering-over-some-flowers-apple-2149485029">TopMicrobialStock/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Pollinators are under siege</h2>
<p>The <a href="https://www.nature.com/articles/s41559-021-01534-9">main threats to pollinators</a> globally are changes in what land is used for and how it is managed. As a result of the shift to modern industrialised farming, flower meadows and hedgerows have been replaced by monocultures and increasingly large fields. Consequently, the diversity of food sources available to pollinators has decreased and farmed landscapes have generally become <a href="https://www.nature.com/articles/nature20588">less hospitable</a> habitats for insects.</p>
<p>The excessive use of chemical pesticides and the impacts of climate change have made matters even worse. Rising temperatures are <a href="https://www.sciencedirect.com/science/article/pii/S0168192322004671">creating a mismatch</a> between crop flowering times and when pollinators emerge. Bumblebees, for example, which are <a href="https://www.nature.com/articles/ncomms8414">vital pollinators</a> for crops both in the UK and globally, are <a href="https://www.science.org/doi/10.1126/science.aaa7031">struggling to shift their range</a> in response to Europe’s warming climate.</p>
<p>Together, these factors are driving losses in the abundance and diversity of pollinator species. Modelling studies have revealed <a href="https://www.nature.com/articles/s41467-019-08974-9">around a 25% drop</a> in the number of bee and hoverfly species observed within any 10km area of the UK compared to the 1980s.</p>
<p>And yet, the UK’s reliance on pollinating insects is likely to increase in the future. </p>
<p>Factors including climate change, technological advancements, shifting market demands and policies promoting sustainable food security mean new and <a href="https://randd.defra.gov.uk/ProjectDetails?ProjectId=20663">underutilised crops</a> such as soy, sunflowers and apricots are likely to be grown in the UK within the coming decades. Many of these crops <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2006.3721">benefit from</a> insect pollination.</p>
<figure class="align-center ">
<img alt="A tractor spraying pesticides on a corn field." src="https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/535383/original/file-20230703-289680-cyhffd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Farming practices have contributed to the destruction of important insect habitats over the past century.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tractor-spraying-pesticides-on-corn-field-1866460120">Fotokostic/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Restoring insects to farms</h2>
<p>Thankfully, there has been a notable shift in farming practices in recent decades towards reducing fertiliser, herbicide and pesticide use and restoring insect habitats. One approach is <a href="https://www.fao.org/pest-and-pesticide-management/ipm/integrated-pest-management/en/">integrated pest management</a>. This is a strategy for sustainable crop pest control that is based on using pesticides only when they are absolutely necessary. </p>
<p>The strategy was developed in response to steadily increasing pesticide use, which caused <a href="https://link.springer.com/article/10.1007/s13593-015-0327-9">environmental damage</a> and pesticide resistance. Farmers using integrated pest management are encouraged to prioritise the protection of natural predators such as wasps and spiders, which can help control pests effectively. </p>
<p>By reducing reliance on pesticides, integrated pest management also helps to protect pollinators. <a href="https://www.nature.com/articles/nature16167">Research</a> shows that bumblebees exposed to neonicotinoid pesticides (a widely used class of pesticide), for example, visited fewer flowers on apple trees and collected pollen less often. </p>
<p>In the UK, farmers are now incentivised to adopt environmentally sustainable practices through the <a href="https://www.gov.uk/government/publications/environmental-land-management-update-how-government-will-pay-for-land-based-environment-and-climate-goods-and-services/environmental-land-management-elm-update-how-government-will-pay-for-land-based-environment-and-climate-goods-and-services">environmental land management scheme</a>. This scheme, which was fully launched in 2023, pays farmers to undertake activities that protect and enhance the natural landscape. These activities include planting hedgerows and flower strips along field boundaries, or creating woodlands. </p>
<p><a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2015.1740">Research</a> demonstrates that expanding natural habitats in the UK’s productive arable farmland can boost pollinating insect populations. And, despite taking a portion of land out of productive agriculture, this approach did not reduce harvests.</p>
<figure class="align-center ">
<img alt="A hedgerow next to a cereal field featuring red and pink poppies." src="https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/535384/original/file-20230703-272779-sljzpk.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">Providing natural habitats along field boundaries can boost insect populations.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/english-hedgerow-featuring-pink-red-poppies-389335">Keith Naylor/Shutterstock</a></span>
</figcaption>
</figure>
<p>Another option is <a href="https://www.britannica.com/science/agroforestry">agroforestry</a>, where tree planting is deliberately combined with agriculture. This approach diversifies the farmed landscape and <a href="https://www.sciencedirect.com/science/article/pii/S0167880920302164?via%3Dihub">has been found</a> to support twice as many pollinators as conventional cropping systems. In the case of apple pollination, these systems can even provide up to four and a half times more pollination.</p>
<p>But to fully <a href="https://www.sciencedirect.com/science/article/pii/S0264837722005245?via%3Dihub">amplify the benefits</a> of agroforestry for pollinators, the UK needs to meet its national tree planting targets of 30,000 hectares per year by 2030. The current rate of tree planting falls significantly short of this target. Between 2018 and 2022, only <a href="https://cdn.forestresearch.gov.uk/2022/09/Ch1_Woodland_2022.pdf">13,000 hectares were planted per year</a> in the UK.</p>
<p>Over the past century, farming practices have contributed to insect declines. Supporting farmers to provide high-quality habitats for insects will not only help to slow down – or even reverse – insect decline, but will help to secure the UK’s food security.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?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>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
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<hr><img src="https://counter.theconversation.com/content/207656/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Potts receives funding from UKRI, NERC, BBSRC, EU, GCRF, Defra, NE, FAO, IUCN, Friends of the Earth, Waitrose, Sainsburys, BerryWorld, Syngenta, Avalon and Worldwide Fruit Limited. </span></em></p><p class="fine-print"><em><span>Michael Garratt receives funding from UKRI, NERC, BBSRC, EU, GCRF, Defra, Reserach Council of Norway, AHDB, UK Gov Green Recovery Challenge Fund, Newton fund, Syngenta, BerryWorld, Avalon and WWF Limited.</span></em></p><p class="fine-print"><em><span>Tom Breeze works for the European Union as a consultant. He has received funding from the European Union and UK Research and Innovation (BBSRC, NERC and ESRC). </span></em></p>Farms have become less friendly for our insect friends – this must be reversed if we want food to eat.Simon Potts, Professor of Biodiversity and Ecosystem Services, University of ReadingMichael Garratt, Principal Research Fellow, University of ReadingTom Breeze, Senior Research Fellow, University of ReadingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2059322023-05-23T20:11:13Z2023-05-23T20:11:13ZCoffee, brought to you by bees: a case study in how restoring habitat is a win-win for forests and farmers<figure><img src="https://images.theconversation.com/files/527609/original/file-20230523-25-1oj0e0.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3872%2C2579&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><a href="https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(05)00302-2">Bees are crucial</a> for producing many of our beloved foods and beverages. Coffee is one crop that <a href="https://www.sciencedirect.com/science/article/pii/S0167880921003844">benefits from bee pollination</a>. </p>
<p>Unfortunately, <a href="https://www.inrae.fr/en/news/pollinator-decline-across-globe-verdict-international-group-scientific-experts">pollinator numbers are falling</a> worldwide. Many are <a href="https://www.weforum.org/agenda/2016/03/40-of-pollinator-species-face-extinction-report-finds/">facing extinction</a>. This decline is <a href="https://abcnews.go.com/International/monoculture-farming-modern-day-agriculture-killing-bees-scientists/story?id=80536659">due in part</a> to ever-expanding farmland covered by a single kind of crop plant – agricultural monocultures. </p>
<p>Restoring pollinators’ habitat is essential, both to stop their decline and to maintain food production. Calls for large-scale restoration, such as the <a href="https://www.decadeonrestoration.org/">UN Decade of Restoration</a>, are ambitious and may compete with other land uses. In addition, restoration often has an upfront cost, while its benefits could take time to obtain. </p>
<p>However, our <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002107">new research</a> shows that coffee farmers who restore patches of forest across their properties can nearly double their profits with just a 15% increase in natural habitat over five years. The benefits, a result of higher pollinator numbers, continue to increase for both farmers and forest over the long term (40 years). This is the first study that assessed such benefits in the long term and at a large scale.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-birds-and-the-bees-help-coffee-plants-181189">How the birds and the bees help coffee plants</a>
</strong>
</em>
</p>
<hr>
<h2>Finding a sweet spot</h2>
<p>Planting trees without planning that takes all factors into account may lead to poor conservation or economic outcomes. For instance, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0012825210001571?via%3Dihub">tree planting in unsuitable arid areas of China</a> ultimately led to further environmental degradation, although the aim was to combat desertification. </p>
<p>For our study, we set up two clear objectives: </p>
<ol>
<li>to maximise coffee profitability</li>
<li>to maximise restoration of forest that pollinators could use. </li>
</ol>
<p>We used Costa Rica as a case study because of the wealth of information on pollination services for coffee in this region. One study found forest-based pollinators <a href="https://www.pnas.org/doi/full/10.1073/pnas.0405147101">increased coffee yields by 20%</a> within 1 kilometre of forest. So the presence of a healthy population of pollinators has a big impact on farmers’ revenue. </p>
<figure class="align-center ">
<img alt="Hands picking coffee berries off the bush" src="https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527611/original/file-20230523-23-agrtzd.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">Coffee production depends on a healthy population of pollinators.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/boosting-bee-diversity-can-help-stabilise-crop-production-new-research-157328">Boosting bee diversity can help stabilise crop production – new research</a>
</strong>
</em>
</p>
<hr>
<p>A common practice to increase profits is to expand cropland by clearing forest. Therefore, restoring coffee lands to forest may involve trade-offs. To account for this, we considered two different planning contexts: </p>
<ol>
<li>only restoration and no agricultural expansion</li>
<li>a mix of restoration and agricultural expansion. </li>
</ol>
<p>We also compared multiple scenarios to assess the trade-offs between focusing solely on coffee profitability (objective one) versus giving more priority to restoring habitat for bees (objective two), and everything in between. Our mathematical modelling then selected the best locations to restore habitat (or expand agriculture) for each scenario.</p>
<p>There was a sweet spot between both objectives when practising only restoration. We found coffee farms can increase economic benefits by 98% after five years by increasing forest area by 15%. After 40 years, the economic benefits increase by about 109% with a 19% increase in forest area. </p>
<p>We also found that if farmers restore habitat without expanding agriculture, profits are steadier. When farmers restore and expand at the same time, this adds an element of volatility.</p>
<figure class="align-center ">
<img alt="Aerial view showing patches of forest among areas of coffee crops" src="https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=521&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=521&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527627/original/file-20230523-4578-jkd8pn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=521&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Farmers need to find a sweet spot between habitat for pollinators and cleared land for growing crops.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/restoring-forests-often-falls-to-landholders-heres-how-to-do-it-cheaply-and-well-204123">Restoring forests often falls to landholders. Here's how to do it cheaply and well</a>
</strong>
</em>
</p>
<hr>
<h2>Small or big patches?</h2>
<p>We found restoring many small patches throughout the farmed area maximised pollination services. Bees can only travel fairly short distances, ranging from 40 metres to 3 kilometres. Dispersed forest patches allowed the bees to reach more coffee plants. </p>
<p>However, while smaller patches are generally suitable for pollinators, other species have different needs. Restoring large areas is important for species that travel longer distances, such as the jaguar (<em>Panthera onca</em>), or for forest specialists that need <a href="https://www.nature.com/articles/nature10425">dense forest to thrive</a>. </p>
<p>However, having only a big patch of restored forest in an area of farmland may isolate species that have a large home range. In contrast, restoring small patches of land can provide <a href="https://link.springer.com/article/10.1007/s13280-013-0470-y">important corridors for mammals</a>. </p>
<p>In our study, we found other solutions that restored a mix of big and small patches at the same time. These solutions can still can deliver good economic and restoration outcomes. Having a mix is important because it allows <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.12666">biodiversity conservation and farming to co-exist</a>.</p>
<p>Ideally, farmers who have large patches restored on their land would receive financial compensation. This could make up for the farmers’ upfront and ongoing costs, such as sapling cost and labour to maintain plants throughout some years. At the same time, <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1002/pan3.10138">neighbouring farms</a> will benefit from bees travelling to and pollinating their crops, even if habitat isn’t restored on this land.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/tropical-forests-can-recover-surprisingly-quickly-on-deforested-lands-and-letting-them-regrow-naturally-is-an-effective-and-low-cost-way-to-slow-climate-change-173302">Tropical forests can recover surprisingly quickly on deforested lands – and letting them regrow naturally is an effective and low-cost way to slow climate change</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="bees on white coffee flowers" src="https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527612/original/file-20230523-17128-uisldi.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">Having forest nearby increases the numbers of bees that can get to the coffee plants and pollinate their flowers.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Importantly, these findings support solutions for farmers with different environmental outlooks. Some farmers may be generally supportive of conservation, leading to more proactive restoration actions and no clearing of forest. Other farmers may place a high importance on expanding agricultural production to improve their livelihoods. </p>
<p>Our study takes into account both contexts. Our findings show strategic habitat restoration for pollinators produces win-win outcomes for farming and the environment in both cases.</p><img src="https://counter.theconversation.com/content/205932/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sofía López-Cubillos is affiliated with Fundación Manigua desde la Tierra in Colombian and the Institute for Capacity Exchange in Environmental Decisions in Australia. </span></em></p><p class="fine-print"><em><span>Rebecca K. Runting receives funding from the Australian Research Council. </span></em></p>The optimal trade-off between restoring habitat and crop production hinges on pollinators. A new study shows giving pollinators more natural habitat on the farm leads to big increases in production.Sofía López-Cubillos, Postdoctoral research fellow, The University of MelbourneRebecca K. Runting, Senior Lecturer in Spatial Sciences and ARC DECRA Fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889392022-11-15T13:22:40Z2022-11-15T13:22:40ZAnts – with their wise farming practices and efficient navigation techniques – could inspire solutions for some human problems<figure><img src="https://images.theconversation.com/files/494699/original/file-20221110-21-p2hi2g.jpg?ixlib=rb-1.1.0&rect=10%2C0%2C2235%2C1329&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Leafcutter ants cultivate fungus gardens that feed sprawling colonies.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/three-leafcutter-ants-carrying-leaves-close-up-royalty-free-image/200187319-004">Tim Flach/Stone via Getty Images</a></span></figcaption></figure><p>King Solomon may have gained some of his famed wisdom from an unlikely source – ants.</p>
<p>According to a <a href="https://www.jewishencyclopedia.com/articles/13842-solomon#anchor14">Jewish legend</a>, Solomon conversed with a clever ant queen that confronted his pride, making quite an impression on the Israelite king. In the biblical book of <a href="https://www.biblegateway.com/passage/?search=Proverbs%206%3A6-8&version=KJV">Proverbs (6:6-8)</a>, Solomon shares this advice with his son: “Look to the ant, thou sluggard, consider her ways and be wise. Which having no guide, overseer, or ruler, provideth her meat in the summer, and gathereth her food in the harvest.”</p>
<p>While I can’t claim any familial connection to King Solomon, despite sharing his name, I’ve long admired the wisdom of ants and have spent over 20 years <a href="https://scholar.google.com/citations?user=bnXkcNUAAAAJ&hl=en&oi=sra">studying their ecology, evolution and behaviors</a>. While the notion that ants may offer lessons for humans has certainly been around for a while, there may be new wisdom to gain from what scientists have learned about their biology.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/vG-QZOTc5_Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ants have evolved highly complex social organizations.</span></figcaption>
</figure>
<h2>Lessons from ant agriculture</h2>
<p>As a researcher, I’m especially intrigued by <a href="https://doi.org/10.1093/isd/ixab029">fungus-growing ants</a>, a group of 248 species that cultivate fungi as their main source of food. They include 79 species of <a href="https://wwnorton.com/books/9780393338683">leafcutter ants</a>, which grow their fungal gardens with freshly cut leaves they carry into their enormous underground nests. I’ve excavated hundreds of leafcutter ant nests from Texas to Argentina as part of the scientific effort to understand how these ants coevolved with their fungal crops.</p>
<p>Much like human farmers, each species of fungus-growing ant is very particular about the type of crops they cultivate. Most varieties descend from a type of fungus that the ancestors of fungus-growing ants began growing <a href="https://doi.org/10.1093/isd/ixab029">some 55 million to 65 million years ago</a>. Some of these fungi became domesticated and are now unable to survive on their own without their insect farmers, much like some human crops such as maize.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-XuPtW8lBCM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ants started farming tens of millions of years before humans.</span></figcaption>
</figure>
<p>Ant farmers face many of the same challenges human farmers do, including the threat of pests. A parasite called <a href="https://doi.org/10.1186/s43008-021-00078-8"><em>Escovopsis</em></a> can devastate ant gardens, causing the ants to starve. Likewise in human agriculture, pest outbreaks have contributed to disasters like the <a href="https://evolution.berkeley.edu/the-relevance-of-evolution/agriculture/monoculture-and-the-irish-potato-famine-cases-of-missing-genetic-variation/">Irish Potato Famine</a>, the 1970 <a href="https://doi.org/10.1126/science.171.3976.1113">corn blight</a> and the <a href="https://theconversation.com/with-the-familiar-cavendish-banana-in-danger-can-science-help-it-survive-64206">current threat to bananas</a>.</p>
<p>Since the 1950s, human agriculture has become industrialized and relies on <a href="https://www.birmingham.ac.uk/research/quest/preserving-and-creating-culture/a-global-history-of-monoculture.aspx">monoculture</a>, or growing large amounts of the same variety of crop in a single place. Yet monoculture makes crops more vulnerable to pests because it is easier to destroy an entire field of genetically identical plants than a more diverse one.</p>
<p>Industrial agriculture has looked to chemical pesticides as a partial solution, turning agricultural pest management into a <a href="https://www.alliedmarketresearch.com/pest-control-market">billion-dollar industry</a>. The trouble with this approach is that pests can <a href="https://islandpress.org/books/chasing-red-queen">evolve new ways to get around pesticides</a> faster than researchers can develop more effective chemicals. It’s an arms race – and the pests have the upper hand.</p>
<p>Ants also <a href="https://mitpress.mit.edu/9780262543200/the-convergent-evolution-of-agriculture-in-humans-and-insects/">grow their crops in monoculture</a> and at a similar scale – after all, a leafcutter ant nest can be home to <a href="https://wwnorton.com/books/9780393338683">5 million ants</a>, all of which feed on the fungi in their underground gardens. They, too, use a pesticide to control <em>Escovopsis</em> and other pests. </p>
<p>Yet, their approach to pesticide use differs from humans’ in one important way. Ant pesticides are <a href="https://doi.org/10.1021/acscentsci.0c00978">produced by bacteria</a> they allow to grow in their nests, and in some cases even on their bodies. Keeping bacteria as a living culture allows the microbes to <a href="https://doi.org/10.1128/AEM.00178-21">adapt in real time</a> to evolutionary changes in the pests. In the arms race between pests and farmers, farming ants have discovered that live bacteria can serve as pharmaceutical factories that can keep up with ever-changing pests.</p>
<p>Whereas recent developments in agricultural pest management have focused on <a href="https://entomology.ca.uky.edu/ef130">genetically engineering</a> <a href="https://www.nature.com/scitable/knowledge/library/use-and-impact-of-bt-maize-46975413/">crop plants</a> to produce their own pesticides, the lesson from 55 million years of ant agriculture is to <a href="https://doi.org/10.3389/fsoil.2022.833181">leverage living microorganisms</a> to make <a href="https://doi.org/10.1007/978-981-16-4843-4_13">useful products</a>. Researchers are currently experimenting with <a href="https://link.springer.com/book/10.1007/978-981-10-0707-1">applying live bacteria to crop plants</a> to determine if they are effective at producing pesticides that can evolve in real time along with pests.</p>
<h2>Improving transportation</h2>
<p>Ants can also offer practical lessons in the realm of transportation.</p>
<p>Ants are notoriously good at quickly locating food, whether it’s a dead insect on a forest floor or some crumbs in your kitchen. They do this by leaving a <a href="https://doi.org/10.1111/j.1365-3032.2008.00658.x">trail of pheromones</a> – chemicals with a distinctive smell ants use to guide their nest mates to food. The shortest route to a destination will accumulate the most pheromone because more ants will have traveled back and forth along it in a given amount of time.</p>
<p>In the 1990s, computer scientists developed a <a href="https://www.sciencedirect.com/topics/engineering/ant-colony-optimization">class of algorithms</a> modeled after ant behavior that are very effective at finding the shortest path between two or more locations. Like with real ants, the shortest route to a destination will accumulate the most virtual pheromone because more virtual ants will have traveled along it in a given amount of time. Engineers have used this simple but effective approach to <a href="https://doi.org/10.1016/j.mcm.2010.04.021">design telecommunication networks</a> and <a href="https://doi.org/10.1007%2F978-3-030-50146-4_25">map delivery routes</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Leafcutter ants crowding a patch of dirt" src="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.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">Thousands of ants can travel along the same path without causing traffic jams.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/close-up-of-plant-growing-on-field-royalty-free-image/764924521">Esteban Castao Solano/EyeEm via Getty Images</a></span>
</figcaption>
</figure>
<p>Not only are ants good at finding the shortest route from their nests to a source of food, thousands of ants are capable of traveling along these routes without causing traffic jams. I recently began collaborating with physicist <a href="https://scholar.google.com/citations?user=reX35vUAAAAJ&hl=es">Oscar Andrey Herrera-Sancho</a> to study how leafcutter ants maintain such a steady flow along their foraging paths without the slowdowns typical of crowded human sidewalks and highways.</p>
<p>We are <a href="http://solomon.rice.edu/2019/01/11/field-research-in-costa-rica/">using cameras to track</a> how each individual ant responds to artificial obstacles placed on their <a href="https://www.alexanderwild.com/Ants/Making-a-Living/The-Farming-Ants-Leafcutters/i-rWjNDhM/A">foraging trails</a>. Our hope is that by getting a better understanding of the rules ants use to respond to both obstacles and the movement of other ants, we can develop algorithms that can eventually help program self-driving cars that never get stuck in traffic.</p>
<h2>Look to the ant</h2>
<p>To be fair, there are plenty of ways ants are far from perfect role models. After all, some ant species are known for <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674241558">indiscriminate killing</a>, and others for <a href="https://theconversation.com/slave-ants-and-their-masters-are-locked-in-a-deadly-relationship-36737">enslaving babies</a>. </p>
<p>But the fact is that ants <a href="https://www.basicbooks.com/titles/mark-w-moffett/the-human-swarm/9781541617292/">remind us of ourselves</a> – or the way we might like to imagine ourselves – in many ways. They live in complex societies with <a href="https://doi.org/10.1007/s00265-015-2045-3">division of labor</a>. They <a href="https://www.simonandschuster.com/books/Ants-At-Work/Deborah-Gordon/9781451665703">cooperate to raise their young</a>. And they accomplish <a href="https://press.princeton.edu/books/hardcover/9780691179315/ant-architecture">remarkable engineering feats</a> – like building structures with air funnels that can house millions – all without blueprints or a leader. Did I mention their societies are <a href="https://www.press.jhu.edu/books/title/10551/secret-lives-ants">run entirely by females</a>?</p>
<p>There is still a lot to learn about ants. For example, researchers still don’t fully understand <a href="https://doi.org/10.1016/j.tree.2020.11.010">how an ant larva develops</a> into either a queen – a female with wings that can live for 20 years and lay millions of eggs – or a worker – a wingless, often sterile female that lives for less than a year and performs all the other jobs in the colony. What’s more, scientists are constantly discovering new species – <a href="https://www.antwiki.org/wiki/Taxa_Described_in_2021">167 new ant species</a> were described in 2021 alone, bringing the total to more than 15,980. </p>
<p>By considering ants and their many fascinating ways, there’s plenty of wisdom to be gained.</p><img src="https://counter.theconversation.com/content/188939/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Scott Solomon receives funding from the National Science Foundation and the Big Thicket Association. </span></em></p>Over hundreds of million years of evolution, ants have come up with some pretty smart solutions to problems of agriculture, navigation and architecture. People could learn a thing or two.Scott Solomon, Associate Teaching Professor of Ecology and Evolutionary Biology, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1705272022-04-05T12:29:53Z2022-04-05T12:29:53ZPlanting mixes of flowers around farm fields helps keep bees healthy<figure><img src="https://images.theconversation.com/files/455012/original/file-20220329-17-5fz4qi.jpeg?ixlib=rb-1.1.0&rect=0%2C7%2C4928%2C3245&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bees feeding in monoculture fields of single crops such as sunflowers crowd together and pass parasites to one another at high rates.</span> <span class="attribution"><span class="source">Lauren Ponisio/University of Oregon</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>It’s springtime in California, and bees are emerging to feast on flowering fields – acres upon acres of cultivated almonds, oranges and other fruits and nuts that bloom all at once for just a few weeks. Farmers raise these lucrative crops in monoculture fields, each planted with neat, straight rows of a single type of crop.</p>
<p>The agricultural heart of California is the Central Valley, one of the most productive agricultural regions in the world. I recently drove north through the valley on Interstate 5, a 450-mile (724-kilometer) stretch of monoculture farms and agricultural land that runs from Bakersfield to Redding. Flowers were blooming as far as the eye could see. There is so much bloom here that commercial beekeepers truck in over 2 million colonies of bees in spring to ensure that every last flower is pollinated.</p>
<p>As a <a href="https://scholar.google.com/citations?user=I8IjAnIAAAAJ&hl=en">bee biologist</a>, I study why bees are <a href="https://theconversation.com/beyond-honey-bees-wild-bees-are-also-key-pollinators-and-some-species-are-disappearing-89214">dying</a>. Although monoculture blooms provide food for bees, scientists know almost nothing about how temporary mass-bloom events influence bee health. </p>
<p>I wondered whether bees in these monoculture fields were getting sick in the same way a crowd of hungry people with unwashed hands can get sick by converging at a brunch buffet. Imagine not washing your hands after picking up the tong for hash browns – hundreds of times in a row. </p>
<p>I found that bees foraging in monoculture pick up parasites at high rates. Disease is a leading cause of bee decline, so my research indicates that monoculture blooms are a threat to bees. However, I also found that farmers can reduce this threat by taking a page from backyard gardens and planting hedgerows with diverse mixes of flowers.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/5ogpp7-lksQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Adding flowering plants to their fields is an effective way for farmers to support bees.</span></figcaption>
</figure>
<h2>Interacting bees can spread disease</h2>
<p>Bees’ main goal in life is to collect pollen and nectar to feed their young. But as bees forage, they are exposed to bacteria, fungi and viruses, which can spread among bees via flowers. </p>
<p>For humans, social interaction or touching shared doorknobs in highly trafficked office buildings can spread viruses and other pathogens. Bee scientists joke that, for bees, <a href="https://doi.org/10.1111/1365-2664.13962">flowers are the dirty office doorknobs</a>. </p>
<p>Artificially providing animals with food can affect the spread of diseases in two ways: It can dilute them or amplify them. When a monoculture crop blooms in a landscape that’s otherwise void of food for bees, it offers an attractive pulse of pollen and nectar. When bees cluster together, disease may be more likely to spread between infected and noninfected bees. </p>
<p>But that’s not automatic. Flowers can feed bees and prop up their immune systems, making them less vulnerable to disease. Disease spread is also hampered if many different bee species are attracted to flowers, because not all bee species harbor all parasite species. </p>
<p>As the mix of bees in the community becomes more diverse, parasites are more likely to encounter unsuitable hosts, breaking up the the chain of transmission. This suggested to my research team that mass blooms could help bees under the right circumstances.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large white boxes with bees on the outside, stacked near blooming almond trees." src="https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/455053/original/file-20220329-27-188nzbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Beehives next to an almond orchard in California’s Central Valley.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/almond-trees-in-spring-bloom-bees-and-beehives-in-almond-news-photo/170485745?">MyLoupe/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>Diagnosing disease</h2>
<p>In a study that <a href="http://www.ponisiolab.com/">colleagues</a> and I published in late 2021, we examined whether monoculture blooms attracted bees, and whether this process <a href="https://doi.org/10.1098/rspb.2021.1369">resulted in more disease or less</a>. We then examined whether adding diverse flowers to monoculture farms helped to promote healthy bees.</p>
<p>We studied bees in sunflower fields in California’s Central Valley. Sunflowers are grown for commercial oil manufacturing and rely heavily on pollinators such as honeybees, bumblebees, sunflower bees and sweat bees.</p>
<p>Some of our sunflower study sites were grown as traditional monocultures, while others were grown adjacent to hedgerows, which are flowering strips of perennial plants such as California rose, Mexican elderberry and perennial sages. These hedgerows turn monoculture farms into more diverse systems.</p>
<p>Our team of professors, postdoctoral researchers and students walked through each site with aerial nets, cajoling bees into tiny sterile tubes. Back in the lab, we tested each bee for seven parasites commonly implicated in bee declines using <a href="https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/biotechnology/a/polymerase-chain-reaction-pcr">molecular techniques</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/455016/original/file-20220329-23-1pzopxs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A hedgerow planted near monoculture sunflower fields provides bees with other flowers to pollinate.</span>
<span class="attribution"><span class="source">Lauren Ponisio/University of Oregon</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Bees really like mass-bloom events. We discovered 35 different bee species visiting sunflowers, with their abundance highest at the peak of sunflower bloom. Places with historic legacies of growing sunflowers hosted more abundant bee populations than sites where sunflowers had been planted only recently. Even at farm sites with hedgerows, bees were consistently found foraging on sunflowers at higher numbers than on hedgerows.</p>
<p>But apparently, bee gluttony comes with a cost. We found that these increases in bee abundance were subsequently associated with higher rates of parasitism. Of the individuals we screened, almost half had at least one parasite, and about a third had multiple parasites. The more bees in sunflower fields, the more parasites. Sunflower blooms were aggregating bees, which in turn was amplifying disease risk.</p>
<h2>Nearby hedgerows help bees</h2>
<p>We also found something encouraging: When bees had access to hedgerows that contained many different kinds of flowers, they had lower rates of parasite infections. This suggests that in the presence of many flower types, bees disperse and spread across resources, reducing each individual bee’s likelihood of encountering an infected individual. Flower diversity may also provide immunity benefits to bees through other mechanisms, perhaps by enhancing nutrition.</p>
<p>[<em>Over 150,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-150ksignup">Sign up today</a>.]</p>
<p>Agencies, organizations and researchers are working to promote hedgerows and other forms of bee habitat. For example, the nonprofit <a href="https://www.xerces.org/pollinator-resource-center/california">Xerces Society</a> offers farmers a certified “Bee Better” eco-label, which indicates to consumers that the farm has dedicated 5% of its land or more to pollinator habitat. And land-grant institutions such as the <a href="https://anrcatalog.ucanr.edu/pdf/8390.pdf">University of California</a>, <a href="https://pollinator.cals.cornell.edu/resources/planting-pollinator-habitat/">Cornell University</a> and the <a href="https://ffl.ifas.ufl.edu/resources/apps/bee-gardens/">University of Florida</a> are teaching local communities about plant choices that work best for bees. As an agricultural extension agent, I believe that together, efforts like these can help bring back healthy pollinators by promoting habitat conservation.</p><img src="https://counter.theconversation.com/content/170527/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Research described in this article was supported by the Foundation for Food and Agriculture. </span></em></p>Huge single-crop fields attract bees in such numbers that they spread parasites to one another. Planting diverse mixes of flowers around fields helps spread out pollinators and keep them healthy.Hamutahl Cohen, Extension Agent, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1745522022-01-24T17:12:52Z2022-01-24T17:12:52ZUrban gardens are crucial food sources for pollinators - here’s what to plant for every season<figure><img src="https://images.theconversation.com/files/441813/original/file-20220120-8260-1ujogi7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A bumblebee visits a blooming honeysuckle plant.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/honeysuckle-bloom-spring-garden-bumblebee-collects-1976580638">Sidorova Mariya | Shutterstock</a></span></figcaption></figure><p>Pollinators are <a href="https://www.science.org/doi/10.1126/science.1255957">struggling to survive</a> in the countryside, where flower-rich meadows, hedges and fields have been replaced by green <a href="https://theconversation.com/single-crop-farming-is-leaving-wildlife-with-no-room-to-turn-38991">monocultures</a>, the result of modern industrialised farming. Yet an unlikely refuge could come in the form of city gardens.</p>
<p>Research has shown how the havens that urban gardeners create provide <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.13598">plentiful nectar</a>, the energy-rich sugar solution that <a href="https://theconversation.com/biodiversity-depends-on-pollinators-a-first-estimate-of-how-many-plants-rely-on-animals-166908">pollinators</a> harvest from flowers to keep themselves flying. </p>
<p>In a city, flying insects like bees, butterflies and hoverflies, can flit from one garden to the next and by doing so ensure they find food whenever they need it.
These urban gardens produce <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.13598">some 85%</a> of the nectar found in a city. Countryside nectar supplies, by contrast, have <a href="https://www.nature.com/articles/nature16532">declined by one-third</a> in Britain since the 1930s. </p>
<p>Our new research has found that this urban food supply for pollinators is also more <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14094">diverse and continuous</a> throughout the year <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13403">than in farmland</a>. Everyone with a garden, allotment or even a window box can create their own haven for pollinators. Here are tips on what to plant for each season.</p>
<figure class="align-center ">
<img alt="Three people in wellington boots work on raised beds in a garden." src="https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441812/original/file-20220120-9372-1jpd6w3.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">Community gardens, allotments, even window boxes can sustain pollinators throughout the year.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/people-taking-care-plants-community-garden-2108650739">KOTOIMAGES | Shutterstock</a></span>
</figcaption>
</figure>
<h2>What to plant in spring</h2>
<p>The first queen bumblebees emerge from winter hibernation in February and March. They need food straight away. </p>
<p>At this time of year nectar-rich plants are vital energy sources for warming up cold flight muscles, with pollen providing the necessary protein for egg laying and larval growth. In early spring much of the countryside is still bleak and inhospitable. </p>
<p>Gardeners can help by planting borders of hellebore, <em>Pulmonaria</em> and grape hyacinth. Trees and shrubs such as willow, cherry and flowering currant are also fantastic for packing a lot of food into a small space.</p>
<figure class="align-right ">
<img alt="A bee on a willow flower" src="https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441983/original/file-20220121-17-14c2na9.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">Willow in bloom.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bee-on-branch-blooming-willow-617939870">Ira Kalinicheva | Shutterstock</a></span>
</figcaption>
</figure>
<h2>What to plant in summer</h2>
<p>In late spring and early summer, pollinators have more food available – but there is also more competition for it. So it is crucial to ensure you have a diverse array of different flowering plants. This will guarantee there is attractive and accessible food to suit a wide range of insects and provide them with nutritionally balanced diets. </p>
<p>A great assortment of plants, including honeysuckle, <em>Campanula</em> and lavender, can provide floral resources in summer. Mowing the lawn a little less often will help too, giving the chance for important so-called weeds, such as clover and dandelion, to bloom.</p>
<figure class="align-left ">
<img alt="Ivy in bloom with a red admiral." src="https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441984/original/file-20220121-13-h0nicm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ivy in bloom with a red admiral.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vanessa-atalanta-sitting-on-ivy-leaves-2084367058">Seepix | Shutterstock</a></span>
</figcaption>
</figure>
<h2>What to plant in autumn</h2>
<p>By late summer and autumn there are fewer species still flowering in gardens. A handful dominate the nectar supplies, particularly <em>Fuchsia</em>, <em>Salvia</em> and <em>Crocosmia</em>. </p>
<p>For many pollinators, however, these flowers are entirely useless. Their nectar is hidden away down a tube, only accessible to insects with long tongues, such as the garden bumblebee.</p>
<p>This means solitary bees and hoverflies may need to find other sources of food. The gardener can help by prioritising open and accessible flowers. Opt for species such as ivy, <em>Sedum</em>, <em>Echinacea</em> and oregano.</p>
<h2>What to plant in winter</h2>
<p>Few pollinators are still active in winter. Most species die off leaving the next generation behind as eggs, larvae or pupae. </p>
<p>But bumblebees and honeybees remain in flight, taking advantage of the warmer climate and winter flowers that cities can provide. By vibrating their wings, bumblebees can warm up to forage in temperatures barely exceeding freezing point, but they need a lot of energy-rich nectar to do so. If you want to attract bees into your garden during the winter some of the best options are <em>Mahonia</em>, sweet box, winter honeysuckle and the strawberry tree.</p>
<figure class="align-center ">
<img alt="Yellow Mahonia on a frosty morning." src="https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441809/original/file-20220120-9595-3p9v0p.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">Mahonia on a frosty morning.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/spray-colorful-mahonia-winter-cover-frost-42886990">Sally Wallis | Shutterstock</a></span>
</figcaption>
</figure>
<p>Urban gardens are small and numerous, with hundreds or even thousands packed into a single square kilometre of a residential neighbourhood. Each gardener is different, with individual preferences of what to plant, how regularly to mow the lawn and even how to decide what constitutes a weed. </p>
<p>This results in an enormous variation from garden to garden in the quantity of nectar, the timing of its production and the types of flowers producing it. But there is always room for improvement. Some gardens provide pollinators with hundreds of times less nectar than others.</p>
<p>So keep yours <a href="https://www.rhs.org.uk/science/conservation-biodiversity/wildlife/plants-for-pollinators">well stocked with nectar</a> and <a href="https://www.rhs.org.uk/about-the-rhs/policies/pesticide-statement">free from toxic pesticides</a>. You’ll be amazed by the impact you can have.</p><img src="https://counter.theconversation.com/content/174552/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicholas Tew receives funding from The Natural Environment Research Council (NERC) and the Royal Horticultural Society (RHS). Nicholas, Katherine and Jane would like to acknowledge the valuable contributions of all co-authors to this study, and in particular, Dr. Stephanie Bird (RHS) for her help with this article.</span></em></p><p class="fine-print"><em><span>Jane Memmott currently receives funding from NERC and has received funding from BBSRC and the Leverhulme Trust in the past.</span></em></p><p class="fine-print"><em><span>Katherine Baldock receives funding from the Natural Environment Research Council (NERC). </span></em></p>Up to 85% of the nectar available to pollinating insects in a city comes from gardens. What we plant – whether in an allotment or a window box – can make a huge difference.Nicholas Tew, PhD Candidate in Community Ecology, University of BristolJane Memmott, Professor of Ecology, University of BristolKatherine Baldock, Senior Lecturer in Ecology, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1444722020-08-20T20:01:50Z2020-08-20T20:01:50ZHow our food choices cut into forests and put us closer to viruses<figure><img src="https://images.theconversation.com/files/353728/original/file-20200819-24757-14rqnkn.jpg?ixlib=rb-1.1.0&rect=8%2C179%2C5447%2C2764&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A palm oil plantation in Malaysia.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>As the global population has doubled to 7.8 billion in about 50 years, industrial agriculture has increased the output from fields and farms to feed humanity. One of the negative outcomes of this transformation has been the extreme <a href="https://doi.org/10.1007/s10980-020-01012-w">simplification of ecological systems</a>, with complex multi-functional landscapes converted to vast swaths of monocultures. </p>
<p>From cattle farming to oil palm plantations, industrial agriculture remains the greatest <a href="https://psmag.com/environment/whats-driving-global-deforestation">driver of deforestation</a>, particularly in the tropics. And as agricultural activities expand and <a href="https://doi.org/10.1016/j.gfs.2019.07.002">intensify</a>, ecosystems lose <a href="http://www.fao.org/news/story/en/item/1180463/icode/">plants, wildlife and other biodiversity</a>.</p>
<p><a href="https://www.doi.org/10.1126/science.aau3445">The permanent transformation</a> of forested landscapes for commodity crops currently drives more than a quarter of all global deforestation. This includes soy, palm oil, beef cattle, coffee, cocoa, sugar and other key ingredients of our increasingly simplified and <a href="https://www.theguardian.com/food/2020/feb/13/how-ultra-processed-food-took-over-your-shopping-basket-brazil-carlos-monteiro">highly processed</a> diets.</p>
<p>The erosion of the forest frontier has also increased our exposure to <a href="https://ipbes.net/covid19stimulus">infectious diseases</a>, such as <a href="https://doi.org/10.1038/s41598-017-14727-9">Ebola</a>, <a href="https://doi.org/10.1016/j.ecolecon.2018.08.005">malaria</a> and other <a href="https://doi.org/10.1038/s41586-020-2562-8">zoonotic diseases</a>. Spillover <a href="https://doi.org/10.1177%2F0030727020931122">incidents would be far less prevalent</a> without human encroachment into the forest. </p>
<p>We need to examine our <a href="https://www.cifor.org/publications/pdf_files/articles/ABahar2001.pdf">global food system</a>: Is it doing its job, or is it contributing to forest destruction and <a href="https://doi.org/10.1007/s10980-020-01092-8">biodiversity loss</a> — and putting human life at risk?</p>
<h2>What are we eating?</h2>
<p>The food most associated with biodiversity loss also tends to also be connected to <a href="http://www.fao.org/3/a-i7846e.pdf">unhealthy diets</a> across the globe. Fifty years after the <a href="https://doi.org/10.1073/pnas.0912953109">Green Revolution</a> — the transition to intensive, high yielding food production reliant on a limited number of crop and livestock species — nearly 800 million people still go to bed hungry; one in three is malnourished; and up to two billion people suffer some sort of micronutrient deficiency and associated health impacts, such as stunting or wasting. </p>
<figure class="align-center ">
<img alt="Forest cut down for an agricultural field" src="https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353908/original/file-20200820-20-4t5bzv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A large soy field cuts into the forest in Brazil.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The <a href="https://ora.ox.ac.uk/objects/uuid:25c20aa7-88b3-4457-9e4d-8ffbf57fc943/download_file?safe_filename=Campbell%2Bet%2Bal%2B2017%2BAgriculture%2Bproduction%2Bas%2Ba%2Bmajor%2Bdriver%2Bof%2Bthe%2BEarth%2Bsystem.pdf&file_format=application%2Fpdf&type_of_work=Journal+article">environmental impacts</a> of our agricultural systems are also severe. The agricultural sector is responsible for up to <a href="https://www.doi.org/10.1038/nature.2012.11708">30 per cent of greenhouse gas emissions</a>, soil erosion, excessive water use, the loss of important pollinators and chemical pollution, among other impacts. It is pushing <a href="https://doi.org/10.5751/ES-09595-220408">planetary boundaries</a> even further. </p>
<p>In short, modern agriculture is failing to sustain the people and the ecological resources on which they rely. The incidence of infectious diseases correlates with the current loss of biodiversity. </p>
<h2>Deforestation and disease</h2>
<p>Few viruses have generated more global response than the SARS-CoV-2 virus responsible for the current pandemic. Yet in the <a href="https://dx.doi.org/10.3389%2Ffmicb.2018.00702">past 20 years</a>, humanity has also faced SARS, MERS, H1N1, Chikungunya, Zika and numerous local outbreaks of Ebola. All of them are zoonotic diseases and at least one, Ebola, has been linked to deforestation.</p>
<p>Farming large numbers of genetically similar livestock along the forest frontier may <a href="https://www.independent.co.uk/environment/coronavirus-meat-animal-farming-pandemic-disease-wet-markets-a9505626.html">provide a route for pathogens</a> to mutate and become transmissible to humans. Forest loss and landscape change bring humans and wildlife into ever-increasing proximity, heightening the risk of an <a href="https://doi.org/10.1098/rspb.2019.2736">infectious disease spillover</a>.</p>
<p>An estimated <a href="https://www.doi.org/10.1126/sciadv.1500052">70 per cent of the global forest estate is now within just one kilometre of a forest edge</a> — a statistic that starkly illustrates the problem. We are destroying that critical buffer that forests provide.</p>
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Read more:
<a href="https://theconversation.com/smaller-farmers-fields-can-reduce-biodiversity-loss-and-increase-wild-plants-birds-beetles-and-bats-139015">Smaller farmer's fields can reduce biodiversity loss and increase wild plants, birds, beetles and bats</a>
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<p>Zoonoses may be more prevalent in simplified systems with lower levels of biodiversity. In contrast, more diverse communities lower the risk of spillover into human populations. This form of natural control is known as the “dilution effect” and illustrates why biodiversity is an important regulatory mechanism.</p>
<p>The pandemic is further <a href="https://news.mongabay.com/2020/07/covid-19-lockdown-precipitates-deforestation-across-asia-and-south-america/">heightening pressures on forests</a>. Increased unemployment, poverty and food insecurity in urban areas is <a href="https://doi.org/10.1016/j.arcmed.2020.06.003">forcing internal migration</a>, as people return to their rural homes, particularly in the tropics. This trend will no doubt increase demands on remaining forest resources for fuel wood, timber and further conversion for small-scale agriculture.</p>
<h2>Wet markets under scrutiny</h2>
<p>The links between zoonoses and wildlife has led to <a href="https://www.worldwildlife.org/stories/why-we-must-close-high-risk-wildlife-markets">many calls</a> during the current pandemic to ban the harvest and sale of wild meat and other forms of animal source foods. That might <a href="https://theconversation.com/banning-bushmeat-could-make-it-harder-to-stop-future-pandemics-138735/">be too hasty a reaction</a>: wild meat is an <a href="https://forestsnews.cifor.org/64855/covid-19-led-ban-on-wild-meat-could-take-protein-off-the-table-for-millions-of-forest-dwellers?">essential resource</a> for millions of rural people, particularly in the absence of alternative animal food sources. </p>
<p>It is, however, not necessarily essential for urban dwellers who do have alternative sources of animal protein to purchase wild meat as a “luxury” item. Urban markets selling wild meat could increase the risk of zoonotic spillover but not all wet markets are the same. There are countless wet markets throughout the world that do not sell wildlife products and such markets are <a href="https://doi.org/10.1007/s10460-019-09987-2">fundamental to the food security and nutrition as well as the livelihoods</a> of hundreds of millions of people. </p>
<figure class="align-center ">
<img alt="Shoppers and vendors in an open-air market, with fruits and vegetables nearby" src="https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353904/original/file-20200820-18-12tkksx.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">Vendors sell vegetables at a wet market in Bangkok, Thailand.</span>
<span class="attribution"><span class="source">(AP Photo/ Gemunu Amarasinghe)</span></span>
</figcaption>
</figure>
<p>Even before the COVID-19 pandemic took hold, international agencies, including the Committee on World Food Security, have <a href="https://doi.org/10.1016/S0140-6736(15)60901-1">been concerned</a> about the long-term viability of our current food system: could it provide diverse and nutritious diets while maintaining environmental sustainability and landscape diversity? The current pandemic has highlighted <a href="https://www.theguardian.com/environment/2020/mar/18/tip-of-the-iceberg-is-our-destruction-of-nature-responsible-for-covid-19-aoe">major shortfalls</a> in our environmental stewardship.</p>
<p>We must harness the interconnected nature of our forests and food systems more effectively if we are to avoid future crises. Better integration of forests, agroforests (the incorporation of trees into agricultural systems) <a href="https://ecoagriculture.org/blog/how-to-reimagine-our-food-systems-for-a-post-covid-world-taking-a-landscape-perspective">at the broader landscape scale</a>, breaking down the institutional, economic, political and spatial separation of forestry and agriculture, can provide the key to a more sustainable, food secure and healthier future.</p><img src="https://counter.theconversation.com/content/144472/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Sunderland currently receives funding from the German Ministry of Nature Protection and Nuclear Safety. </span></em></p>Forests provide an essential buffer between people and wildlife — and the viruses they carry. Global agriculture is destroying forests, harming biodiversity and may be putting human life at risk.Terry Sunderland, Professor in the Faculty of Forestry, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/810612017-07-17T23:10:08Z2017-07-17T23:10:08ZHow changing your diet could save animals from extinction<figure><img src="https://images.theconversation.com/files/178513/original/file-20170717-6069-118ptx8.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3329%2C2562&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nearly one-third of tropical animal species face extinction if humans do not curb our growing appetites for beef, pork and other land-intensive meats. The Panamanian golden frog bred by the Vancouver Aquarium in this 2014 file photo may be extinct in its natural habitat.</span> <span class="attribution"><a class="source" href="http://www.cpimages.com/fotoweb/cpimages_details.pop.fwx?position=4&archiveType=ImageFolder&sorting=ModifiedTimeAsc&search=golden%20and%20frog&fileId=7ED4E565C8CEED275AEAE4A023E6F0DBFE75CC55B6586039AFA3A4A9FE951D3F22B34ACC50499F0099000C676EF56B79FD8133928F397B4233BD2F0B4AD858FA1638DDC87EBA9DB8E94B0839D79C227DF75A92B14A2B5F1A1225BCBD55DF59F06EB5BD7C5D2616EF6A9A1C79CADDD85732C9D97DC19FAC898908539CF52E943D">(THE CANADIAN PRESS/Darryl Dyck)</a></span></figcaption></figure><p>Transforming large swaths of the tropics into farmland could render almost one-third of wildlife there extinct, new research suggests. </p>
<p>From the Amazon rain forests to the Zambezi floodplains, intensive <a href="https://www.nature.com/articles/s41559-017-0234-3.epdf?author_access_token=b6E1O0fG6Z2pt7i17O5LcdRgN0jAjWel9jnR3ZoTv0Pk8s5ohTQBT5s50rsawiGLYGm5dBnXDBv1BU9t-BbojU0HQHmSIi7-KmQMAcQb1FgkSHgkdZLVFDTFxUt1byLe-6By_qDh-GymAFfpKHOMSA%3D%3D">monoculture farming could have a severe adverse impact on wildlife</a> around the world. </p>
<p>Wildlife would disappear most dramatically in the remaining forests and grasslands of Latin America and Sub-Saharan Africa. The greatest species loss would occur in the Peruvian Amazon basin where as many as 317 species could vanish as a result of agricultural development. </p>
<p>As a doctoral researcher at Humboldt University Berlin, I studied human food consumption, land use and how they affect wildlife. Our research was published July 17 in Nature Ecology and Evolution.</p>
<p>While human population has doubled since 1970, the number of <a href="http://wwf.panda.org/about_our_earth/all_publications/lpr_2016/">birds, mammals, reptiles and amphibians have dropped by more than half</a>. At its root, this widespread environmental destruction is a result of our growth as a species and increasing food consumption to sustain ourselves.</p>
<p>Although climate change casts a shadow over future conservation efforts, farming is the <a href="https://www.nature.com/nature/journal/v546/n7656/full/nature22900.html">No. 1 threat to wildlife</a>. We have already <a href="http://onlinelibrary.wiley.com/doi/10.1890/070062/abstract">altered some 75 per cent of the ice-free land</a> on this planet. If we continue along our current course, <a href="http://www.pnas.org/content/108/50/20260">we will need to double our crop production</a> to feed a growing world population that demands more resource-intensive foods such as meat and dairy.</p>
<h2>Africa at risk</h2>
<p>Our research shows that Sub-Saharan Africa is particularly at risk of harmful agricultural development. This region is at the crossroads of economic, demographic and agricultural growth, and minimizing potential effects of agricultural change there is an urgent challenge.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=181&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=181&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=181&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=228&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=228&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=228&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The potential biodiversity loss due to agricultural expansion and intensification worldwide could be as high as 317 species in some locales (left), reaching 31 per cent of known vertebrate animals (right).</span>
<span class="attribution"><span class="source">(Laura Kehoe)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This becomes more worrying when considering the percentage of land that is currently at risk (i.e. natural but arable) and not protected against future development. Four-fifths of the regions we identify at risk of farmland expansion in Sub-Saharan Africa are unprotected. This is less than half of the 43 per cent protected in Latin America.</p>
<p>Some may mistakenly believe that protecting land from farming is about preserving wildlife habitat while local people go hungry. But it’s not a binary choice. Instead, the goal is to ensure an ample supply of nutritious food while at the same time conserving the most biodiverse and unique places on Earth. This is possible if we try. Knowing in advance what areas are most at risk allows us to better plan for a more sustainable future.</p>
<p>Aside from protecting land, food can be grown at little to no cost to biodiversity. For example, small-holder agro-ecological farming, which uses diverse cropping techniques along with fewer chemical fertilizers and pesticides, can produce <a href="http://www.sciencedirect.com/science/article/pii/S0006320712000821">large quantities of nutritious food at little to no cost</a> to wildlife. </p>
<p>We need to increase awareness of agro-ecological farming methods and secure local people’s land-holder rights — a crucial step to preventing large foreign corporations from buying up land for monoculture farming. </p>
<p>Communities adopting agro-ecological techniques is a win-win solution that goes a long way towards sustainably feeding the world without pushing wildlife towards extinction.</p>
<h2>What can policy makers do?</h2>
<p>Current large-scale <a href="http://www.conservation.org/How/Pages/Hotspots.aspx">conservation schemes</a> are based on factors that include past habitat loss and the threatened status of species, but none include the potential for future land-use change. We need to do a better job of predicting future pressures on wildlife habitat, especially because timely conservation action is cheaper and more effective than trying to fix the damage caused by farming. Our research takes a step in this direction.</p>
<p>We also show which countries could do with more support for conservation initiatives to protect land and find ways to sustainably grow food. Suriname, Guyana and the Republic of the Congo are just a few examples, as well as a number of countries in Latin America and Sub-Saharan Africa that are at the centre of high agricultural growth, low conservation investment and very high numbers of species that could be lost due to agricultural development. </p>
<p>Since most agricultural demand comes from richer nations, those countries should provide education and support for sustainable farming methods and locally led conservation efforts. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=590&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=590&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=590&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=741&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=741&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=741&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map shows countries at risk of high species loss from agricultural development (yellow, bear icon), rapid agricultural growth 2009 to 2013 (orange, tractor symbol), and differing levels of conservation spending. Red represents low spending, high growth, and high species loss. Purple shows high spending, high growth, and low species loss. Green is high spending, low growth, and high species loss. Low values for all three factors are in grey. White represents no data. Dollar figures per square kilometre.</span>
<span class="attribution"><span class="source">Laura Kehoe</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What can you do?</h2>
<p>All of this raises the question: How can we eat well without harming wildlife? One simple step we can all take right now that would have a far greater impact than any other (aside from having fewer children): Cut out the grain-fed beef. </p>
<p>The inefficiency of feeding livestock grain to turn them into meals for humans makes a <a href="http://www.sciencedirect.com/science/article/pii/S0048969715303697">diet heavy in animals particularly harsh on the Earth’s</a> resources. For example, in the United States, it takes <a href="https://books.google.ca/books/about/Should_We_Eat_Meat_Evolution_and_Consequ.html">25 kilograms of grain to produce one kilogram of beef</a>. Pigs have a grain-to-meat-ratio of 9:1, and chickens are 3:1. </p>
<p>Imagine throwing away 25 plates of perfectly good food to get one plate of beef — the idea is absurd and would likely be news if done en masse. But that is precisely what we are all unknowingly doing by eating resource-intensive meat. Articles on food waste seem half-baked when keeping in mind the bizarre grain-to-meat ratio of many of our most popular meats. </p>
<p>There are ways in which farmers can raise livestock with little to no environmental damage, particularly when land is not overgrazed and trees remain on the landscape. Indeed, in some remote areas grazing cattle are a crucial source of food and nourishment. Unfortunately, the industrialized feedlot model that relies heavily on grain makes up the overwhelming majority of the meat in your supermarket. That is the kind of farming that our research investigates.</p>
<h2>Livestock and deforestation</h2>
<p>To make matters worse, the grain we feed animals is the leading driver of deforestation in the tropics. And it’s a hungry beast: our <a href="http://www.nature.com/nature/journal/v478/n7369/full/nature10452.html">cows, pigs, and poultry devour over one-third of all crops</a> we grow. Indeed, the grain we feed to animals in the U.S. alone <a href="http://news.cornell.edu/stories/1997/08/us-could-feed-800-million-people-grain-livestock-eat">could feed an additional 800 million people</a> if it were eaten by us directly — more than the number of <a href="http://www.worldhunger.org/2015-world-hunger-and-poverty-facts-and-statistics/">people currently living in hunger</a>. </p>
<p>Livestock quietly causes <a href="http://www.ucsusa.org/global-warming/stop-deforestation/whats-driving-deforestation#.WSsT8e1tnIU">10 times more deforestation</a> than the palm oil industry but seems to get about 10 times less media attention. While it’s certainly true that avoiding unsustainable palm oil is a good idea, avoiding eating animals that were raised on grain is an even more effective conservation tactic.</p>
<p>Feeding the world without damaging nature is one of the greatest challenges humanity faces. But with a little foresight, better land governance and some simple meal changes, many of the solutions are at arm’s length. </p>
<p>For wildlife’s sake, go forth and enjoy your veggie burgers.</p><img src="https://counter.theconversation.com/content/81061/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Kehoe 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>As much as one-third of animal species in the tropics could be eradicated if their habitats continue to be converted for monoculture farming. We can all do something to make a difference.Laura Kehoe, Researcher in Conservation Decision Science and Land Use, University of VictoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/642062016-10-24T01:59:53Z2016-10-24T01:59:53ZWith the familiar Cavendish banana in danger, can science help it survive?<figure><img src="https://images.theconversation.com/files/142716/original/image-20161021-1763-13xoceb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Facing down a future with no bananas.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/35652152@N07/28004881235">Chris Richmond</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>The banana is the world’s most popular fruit crop, with <a href="http://www.fao.org/economic/worldbananaforum/statistics/en/">over 100 million metric tons produced annually</a> in over 130 <a href="http://www.fao.org/docrep/019/i3627e/i3627e.pdf">tropical and subtropical countries</a>. Edible bananas are the result of a genetic accident in nature that created the seedless fruit we enjoy today. </p>
<p>Virtually all the bananas sold across the Western world belong to the <a href="http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0007/251899/Banana-growing-guide-cavendish-bananas-1.pdf">so-called Cavendish subgroup</a> of the species and are <a href="http://doi.org/10.1093/aob/mcm191">genetically nearly identical</a>. These bananas are sterile and <a href="http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/251898/Banana-growing-guide-cavendish-bananas-Complete.pdf">dependent on propagation via cloning</a>, either by using suckers and cuttings taken from the underground stem or through modern tissue culture.</p>
<p>The familiar bright yellow Cavendish banana is ubiquitous in supermarkets and fruit bowls, but it is in imminent danger. The vast worldwide monoculture of genetically identical plants leaves the Cavendish <a href="http://dx.doi.org/10.1371/journal.ppat.1005197">intensely vulnerable to disease outbreaks</a>. </p>
<p>Fungal diseases severely devastated the banana industry once in history and it could soon happen again if we do not resolve the cause of these problems. Plant scientists, including us, are working out the genetics of wild banana varieties and banana pathogens as we try to prevent a Cavendish crash. </p>
<h2>The cautionary tale of ‘Big Mike’</h2>
<p>One of the most prominent examples of genetic vulnerability comes from the banana itself. Up until the 1960s, Gros Michel, or “Big Mike,” was the prime variety grown in commercial plantations. Big Mike was so popular with consumers in the West that the banana industry established ever larger monocultures of this variety. Thousands of hectares <a href="http://www.apsnet.org/publications/apsnetfeatures/Pages/PanamaDiseasePart1.aspx">of tropical forests</a> in Latin America were converted into <a href="http://www.penguinrandomhouse.com/books/299017/banana-by-dan-koeppel/9780452290082">vast Gros Michel plantations</a>.</p>
<p>But Big Mike’s popularity led to its doom, when a pandemic whipped through these plantations during the 1950s and ‘60’s. A fungal disease called Fusarium wilt or Panama disease nearly wiped out the Gros Michel and brought the global banana export industry to the <a href="http://www.agriculturedefensecoalition.org/sites/default/files/pdfs/3T_2000_Banana_Destructive_Panama_Disease_2000.pdf">brink of collapse</a>. A soilborne pathogen was to blame: The fungus <em>Fusarium oxysporum</em> f.sp. <em>cubense</em> (Foc) <a href="http://dx.doi.org/10.1094/PHYTO-04-15-0101-RVW">infected the plants’ root and vascular system</a>. Unable to transport water and nutrients, the plants wilted and died.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142717/original/image-20161021-1778-1ihcafz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A cross-section of a banana plant, infected with the fungus that causes Fusarium wilt.</span>
<span class="attribution"><span class="source">Gert Kema</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Fusarium wilt is <a href="http://www.promusa.org/Fusarium+wilt">very difficult to control</a> – it spreads easily in soil, water and infected planting material. Fungicide applications in soil or in the plant’s stem are as of yet ineffective. Moreover, the fungus can persist in the soil for several decades, thus prohibiting replanting of susceptible banana plants. </p>
<h2>Is history repeating itself?</h2>
<p>Cavendish bananas are resistant to those devastating Fusarium wilt Race 1 strains, so were able to replace the Gros Michel when it fell to the disease. Despite being less rich in taste and logistical challenges involved with merchandising this fruit to international markets at an acceptable quality, <a href="http://www.apsnet.org/publications/apsnetfeatures/Documents/2005/PanamaDisease2.pdf">Cavendish eventually replaced Gros Michel</a> in commercial banana plantations. The <a href="http://www.fao.org/fileadmin/templates/est/COMM_MARKETS_MONITORING/Bananas/Documents/Banana_Information_Note_2014-_rev.pdf">entire banana industry</a> was restructured, and to date, Cavendish accounts for <a href="http://www.fao.org/docrep/007/y5102e/y5102e04.htm">47 percent of the bananas grown worldwide</a> and <a href="http://www.newyorker.com/magazine/2011/01/10/we-have-no-bananas">99 percent of all bananas sold commercially for export</a> to developed countries. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142718/original/image-20161021-1763-1fza2aq.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">Bananas in Costa Rica affected by Black Sigatoka.</span>
<span class="attribution"><span class="source">Gert Kema</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But the Cavendish unfortunately has its own weaknesses – most prominently susceptibility to <a href="http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2003.87.3.208">a disease called Black Sigatoka</a>. The fungus <em>Pseudocercospora fijiensis</em> attacks the plants’ leaves, causing cell death that affects photosynthesis and leads to a reduction in fruit production and quality. If Black Sigatoka is left uncontrolled, <a href="http://doi.org//10.1111/j.1364-3703.2010.00672.x">banana yields can decline</a> by <a href="http://www.apsnet.org/edcenter/intropp/lessons/fungi/ascomycetes/Pages/BlackSigatoka.aspx">35 to 50 percent</a>.</p>
<p>Cavendish growers currently manage Black Sigatoka through a combination of pruning infected leaves and <a href="http://doi.org/10.17660/ActaHortic.2009.828.16">applying fungicides</a>. Yearly, it can take 50 or more applications of chemicals to control the disease. Such heavy use of fungicides has negative impacts on the environment and the occupational health of the banana workers, and increases the costs of production. It also helps select for survival the strains of the fungus with <a href="http://www.frac.info/working-group/banana-group">higher levels of resistance to these chemicals</a>: As the resistant strains become more prevalent, the disease gets harder to control over time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=278&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=278&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=278&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=350&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=350&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142816/original/image-20161024-15958-1gmv13y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=350&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aerial spraying of fungicides on a banana plantation.</span>
<span class="attribution"><span class="source">Gert Kema</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>To further aggravate the situation, Cavendish is also now under attack from <a href="http://dx.doi.org/10.1094/PHYTO-04-15-0101-RVW">a recently emerged strain of Fusarium oxysporum</a>, known as Tropical Race 4 (TR4). First identified in the early 1990s in Taiwan, Malaysia and Indonesia, TR4 has since spread to many Southeast Asian countries and <a href="http://dx.doi.org/10.1094/PDIS-12-14-1356-PDN">on into the Middle East</a> and <a href="http://dx.doi.org/10.1094/PDIS-09-13-0954-PDN">Africa</a>. If TR4 makes it to Latin America and the Caribbean region, the export banana industry in that part of the world could be in big trouble.</p>
<p>Cavendish varieties have shown <a href="http://dx.doi.org/10.1038/504195a">little if any resistance against TR4</a>. Growers are relying on temporary solutions – trying to <a href="http://www.promusa.org/Fusarium+wilt">prevent it</a> from entering new regions, using clean planting materials and limiting the transfer of potentially infected soil between farms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142714/original/image-20161021-1796-1on3qw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Cavendish banana trees in China infected with new fungal disease TR4.</span>
<span class="attribution"><span class="source">Andre Drenth, UQ</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Black Sigatoka and Panama disease both cause serious production losses and are difficult to control. With the right monitoring in place to rapidly intervene and halt their spread, the risks and damage imposed by these diseases can be considerably reduced, as has been <a href="http://www.musalit.org/seeMore.php?id=14394">recently shown in Australia</a>. But current practices don’t provide the durable solution that’s urgently needed.</p>
<h2>Getting started on banana genetic research</h2>
<p>If there’s a lesson to be learned from the sad history of Gros Michel, it’s that reliance on a large and genetically uniform monoculture is a risky strategy that is prone to failure. To reduce the vulnerability to diseases, we need more genetic diversity in our cultivated bananas. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/140963/original/image-20161008-21433-5f2wkn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Local banana varieties in southern China.</span>
<span class="attribution"><span class="source">Andre Drenth, UQ</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Over a thousand species of banana have been recorded in the wild. Although most do not have the desired agronomic characteristics – such as high yields of seedless, nonacidic fruits with long shelf life – that would make them a direct substitute for the Cavendish, they are an untapped genetic resource. Scientists could search within them for resistance genes and other desirable traits to use in engineering and breeding programs.</p>
<p>To date, though, there’s been little effort and insufficient funding for collecting, protecting, characterizing and <a href="http://dx.doi.org/10.17660/ActaHortic.2011.897.4">utilizing wild banana genetic material</a>. Consequently, while almost every other crop used for food production has been significantly improved through plant breeding over the last century, the banana industry has yet to benefit from genetics and plant breeding.</p>
<p>But we have started taking the first steps. We now know the <a href="http://dx.doi.org/10.1038/nature11241">genome sequences of the banana</a> and the fungi that <a href="http://dx.doi.org/10.1371/journal.pone.0095543">cause Fusarium wilt</a> and <a href="http://dx.doi.org/10.1371/journal.pgen.1005904">Sigatoka</a>. These studies helped illuminate some of the molecular mechanisms by which these fungal pathogens cause disease in the banana. That knowledge provides a basis for <a href="http://dx.doi.org/10.1371/journal.pgen.1005904">identifying disease-resistant genes</a> in wild and cultivated bananas.</p>
<p>Researchers <a href="http://dx.doi.org/10.1371/journal.pgen.1005876">now have the tools</a> to <a href="https://www.google.co.in/patents/WO2011005090A1?cl=en">identify resistance genes</a> in wild bananas <a href="http://dx.doi.org/10.1073/pnas.1002910107">or other plant species</a>. Then they can use classical plant breeding or genetic engineering to transfer those genes into desired cultivars. Scientists can also use these tools to further study the dynamics and evolution of banana pathogens in the field, and monitor changes in their resistance to fungicides.</p>
<p>Availability of the latest tools and detailed genome sequences, coupled with long-term visionary research in genetics, engineering and plant breeding, can help us keep abreast of the pathogens that are currently menacing the Cavendish banana. Ultimately we need to increase the pool of genetic diversity in cultivated bananas so we’re not dependent on single clones such as the Cavendish or the Gros Michel before it. Otherwise we remain at risk of history repeating itself.</p><img src="https://counter.theconversation.com/content/64206/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>André Drenth receives funding from Horticulture Innovation Australia </span></em></p><p class="fine-print"><em><span>Gert Kema is a senior scientist and professor of tropical phytopathology at Wageningen University and Research. He receives funding for his R&D program on banana, see <a href="http://www.panamadisease.org">www.panamadisease.org</a>. He also co-founded two companies dealing with banana and owns shares in Yellow Pallet, a company that produces transport pallets from banana fiber. </span></em></p><p class="fine-print"><em><span>Ioannis Stergiopoulos does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Every single Cavendish banana plant worldwide is genetically identical. This vast monoculture sets them up for disastrous disease outbreaks. But researchers have ideas on how to protect the crop.Ioannis Stergiopoulos, Assistant Professor of Plant Pathology, University of California, DavisAndré Drenth, Professor of Agriculture and Food Sciences, The University of QueenslandGert Kema, Special Professor of Phytopathology, Wageningen UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/546982016-03-11T11:12:33Z2016-03-11T11:12:33ZCan we ‘vaccinate’ plants to boost their immunity?<figure><img src="https://images.theconversation.com/files/114727/original/image-20160310-26261-7ib0hc.jpg?ixlib=rb-1.1.0&rect=221%2C786%2C2767%2C1476&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Our modern crops need some help in the immunity department.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/ndrwfgg/173181035">Andy / Andrew Fogg</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>When you pick up the perfect apple in the supermarket it’s easy to forget that plants get sick just like we do. A more realistic view might come from a walk outside during summer: try to find a leaf without a speck, spot or blemish. Tough, huh? Those are the signs of a microscopic battle waged every day in and on plants.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=582&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=582&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114742/original/image-20160310-26279-stkxxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=582&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Plants get sick too.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Lumbar_plant_acerleaf_sick.jpg">Carsten Niehaus</a></span>
</figcaption>
</figure>
<p>Just like us, plants are covered in microbes. And just like us, plants have evolved an immune system to protect against the dangerous ones. But our current agricultural system works against plants’ natural immune defenses, by limiting the tools plants have to fight back and restricting evolution of new tools. </p>
<p>Pesticides provide us with most of the spotless produce in the grocery store. Even so, many apples still don’t make it to market. About a <a href="https://www.usitc.gov/publications/332/ITS_4.pdf">third end up</a> as juice or applesauce, because they don’t meet the beauty standards of the American consumer. Forget about blemishes – <a href="http://panamadisease.org/en/theproblem">Panama Disease</a> threatens nearly all of the world’s banana production, and the only effective treatment is toxic to the soil.</p>
<p>Scientists studying plant immunity are figuring out how to fight plant diseases without chemical pesticides. Some researchers plan to <a href="https://theconversation.com/primed-for-battle-helping-plants-fight-off-pathogens-by-enhancing-their-immune-systems-43689">give our crops vaccines</a>, just like the shots we administer to ourselves to fend off the flu or smallpox. My lab seeks to identify ways plants defend themselves in the wild. With that information, we can use modern breeding techniques and genetic engineering to strengthen the immunity of our crops and gardens.</p>
<h2>Plants have naturally evolving “resistance genes”</h2>
<p>Over the last 25 years, advances in genetics and molecular biology have revealed new secrets of <a href="https://en.wikipedia.org/wiki/Plant_disease_resistance">plant immunity</a>. Computers, searching mountains of plant genetic data, have identified thousands of “<a href="http://prgdb.crg.eu/wiki/Main_Page">resistance genes</a>” that <a href="http://doi.org/10.1038/nature05286">help plants fend off infection</a>.</p>
<p>These genes are the blueprints for resistance proteins that look surprisingly like the antibodies in the human immune system. Both are modular in nature and recognize specific invading pathogens. Like a lock and key, only the proper resistance protein “lock” will recognize its corresponding pathogen “key.”</p>
<p>Resistance proteins also contain a switch to alert the plant that a potential threat has been found. Without the proper lock and key combination, the plant never knows the pathogen is there. If the resistance protein identifies a pathogen, other immune functions and defenses turn on to fight the intruder and attempt to keep the plant from getting “sick.” </p>
<p>Animals’ immunity has a distinct advantage over plants’, though. New <a href="http://www.imgt.org/IMGTeducation/Tutorials/ImmuneSystem/UK/the_immune_system.pdf">antibodies are made fresh by human immune cells</a> to recognize new pathogens we might encounter. Plants are stuck with what they’ve got. All the resistance genes they have were passed down from their parents.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114764/original/image-20160311-26274-5p03tr.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">Modern farms support much less diversity – and contain less immunity – than a natural wildflower field.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/barbarawalsh/5944251580">Barbara Walsh</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Diversity is a key part of plant immune systems</h2>
<p>Bacteria and fungi with short life cycles can evolve more quickly than plants. These pathogens can complete a life cycle in a week and produce millions of offspring. If even one changes or drops the molecular “keys” recognized by a resistance protein, it could start a new family of pathogens capable of infecting the plant.</p>
<p>Due to the rigidity of inherited resistance, only genetic variety among a plant species can provide a variety of resistances to pathogens. The more diverse the population of plants, the more diverse the resistance genes in the population. </p>
<p>Resistance genes’ modular nature allows computers to find them, and is also critical for their evolution. This characteristic allows for quick rearrangements and new combinations. The mixing of genes during plant sex can lead to new chimeric resistance genes made of bits and pieces of the parents’ genes. Even as the pathogens change to evade the plant, resistance genes can evolve over the generations to recognize and fight them. </p>
<p>Human beings’ <a href="http://www.fao.org/docrep/007/y5609e/y5609e02.htm">reliance on monoculture</a> for our food supply <a href="http://doi.org/10.1016/j.soilbio.2013.06.007">works against</a> the plants’ natural defenses. Without a variety of resistance gene modules to work with, the plant community struggles to hit on new winning combinations. Not only are we halting the natural evolution of resistance genes, but if every plant in the field is identical, then disease that infects one can infect them all.</p>
<p>The plant pathogens are evolving, but we continue to grow the same plants, with the same resistance genes. To compensate, we rely <a href="http://quickstats.nass.usda.gov">more and more on pesticides</a> to keep our crop plants healthy. Without new resistance genes our <a href="https://www.washingtonpost.com/news/wonk/wp/2015/12/04/the-worlds-most-popular-banana-could-go-extinct/">current crops of bananas</a> and <a href="http://www.nature.com/news/planetary-disasters-it-could-happen-one-night-1.12174">potatoes may fail</a>. </p>
<h2>Compensating for the diversity our crops lack</h2>
<p><a href="http://www.fralin.vt.edu/affiliated-faculty/john-mcdowell">Our lab</a> and collaborators seek to find resistance genes in wild relatives of the soybean to <a href="http://dx.doi.org/10.1094/PDIS-08-15-0916-RE">breed into commercial varieties</a>. We play the role of natural selection by choosing diverse resistance that protects against economically important diseases.</p>
<p>Breeding can be slow and is especially difficult if the plants are only distantly related. So other labs and companies are using genome editing technologies to introduce new resistance genes quickly.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114762/original/image-20160310-26271-1o9a4mr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A potato suffering from late blight, the disease responsible for the Irish potato famine.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/usdagov/5050443007">U.S. Department of Agriculture</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Take the example of potatoes and late blight, the disease that caused the Irish potato famine in the 19th century. Today, farmers spray fungicide as many as <a href="http://www.ipm.ucdavis.edu/PMG/r607101211.html">15 times a year</a> to combat the disease on potatoes. A <a href="http://dx.doi.org/10.1046/j.1365-313X.2003.01934.x">decade of research</a> identified and isolated a resistance gene in wild potato to fight late blight. Chemical company BASF genetically modified (GM) cultivated potato varieties in an attempt to market a GM, disease-resistant product. The <a href="http://www.rsc.org/chemistryworld/2013/02/basf-gm-potato-amflora">project was abandoned</a> in 2013 due to lack of interest and high regulatory barriers.</p>
<p>US regulators have recently approved new <a href="http://www.simplotplantsciences.com">“Innate” potato</a>, a GM variety with resistance genes from wild potato relatives. These potatoes recognize, and fight back against late blight – without the help of fungicide. </p>
<p>The use of genetic modification in food is still controversial. Many think GM plants need more testing; others say they are not natural. <a href="http://bigstory.ap.org/article/94da41eac8a64ff8a14b072bcd14fe0a/fda-gives-ok-companys-genetically-engineered-potato">McDonald’s will not use the Innate potato</a> for its French fries. Everyone can buy and eat as they choose. But sometimes I want to bite into that perfect red apple or enjoy a bag of French fries. For me, at least, the potato plant fighting for itself with the help of an added gene is more appealing than weekly applications of <a href="http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/chlorothalonil-ext.html">fungus-killing chemical chlorothalonil</a>. </p>
<p>Some scientists are going a step further. Just this year researchers showed how they <a href="http://doi.org/10.1126/science.aad3436">customized a resistance gene</a>. In this case, rather than borrowing from nature, the “locks” have been engineered in the lab to recognize a specific pathogen “key.” Putting the new resistance gene in plants confers synthetic immunity.</p>
<p>This research is still only at the in-the-lab stage, but it opens the hopeful possibility that even if diseases evolve to evade all natural plant resistance, we can engineer tools to stop them.</p><img src="https://counter.theconversation.com/content/54698/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Herlihy is a graduate student at Virginia Tech, and receives funding from Virginia Tech and North Carolina State University. </span></em></p>Modern agriculture is synonymous with monoculture. That lack of diversity is bad news for plants’ natural immune defenses. Researchers are figuring out how to help plants fend off microbes – without pesticides.John Herlihy, Ph.D. Student in Plant Pathology, Physiology and Weed Science, Virginia TechLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/454772015-07-31T18:04:47Z2015-07-31T18:04:47ZAs biodiversity declines on corn farms, pest problems grow<figure><img src="https://images.theconversation.com/files/90363/original/image-20150730-25784-kw1a3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Teeming with insect life?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/oragriculture/12506035615/in/photolist-k47GFH-abesfe-53ty7C-arutzU-dtjNHJ-votfbA-dcvG6F-gXqRMy-oio6EE-7ZZwbW-3KpNra-8PHfGb-aiycb8-rGUEYY-6mAojo-6f8wf6-chxnf7-uQWxEK-wqBzC-5vjpuQ-5pbmhw-fr4S7B-9SrTph-f3Gn3E-9ZW6Bx-5f6XzW-akjAi3-5dw1We-doXpPe-59B5J-nwiAP5-7Xk7EK-fK9Rb9-8kTXVW-acRgkK-i6aoBo-mTQXih-2tqH5u-aQPnWD-4YZPHr-55rpHe-uESsNG-mTQM3g-6HN7wT-b4SJhM-bbLxxx-6HN9Mk-6K7Ddc-hd2tta-5ijgqV">Oregon Department of Agriculture</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Biodiversity performs critical ecosystem functions that cannot be replaced indefinitely by technology, such as pesticides and herbicides. This includes a diverse population of insects on farms. </p>
<p>In a study of corn farms across the Northern Great Plains, we found that farms with lower insect biodiversity have more pests. The findings suggest that farming practices that promote insect biodiversity may be an effective way to control pests.</p>
<p>The more connections we can make between diversity and the benefits that it provides, the more we will enable the design of resilient food production systems that are ecologically sustainable in the long term.</p>
<h2>Biological networks</h2>
<p>Pests are a major threat to food production, and pest control efforts can produce unintended consequences to the environment and to society, such as toxicity to beneficial species and wildlife, the contamination of soil and water, and increased costs for food production.</p>
<p>Previous researchers have documented that species diversity within agroecosystems can reduce pest populations, but often these studies favor controlled, simplified experiments rather than focusing on realistic communities observed on operating farms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/90364/original/image-20150730-25742-8vv22d.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">Of the 106 insect species found in corn farms in the Midwest, 87% of them, like this damsel bug, are beneficial pest predators.</span>
<span class="attribution"><span class="source">Jonathan Lundgren</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>One reason for focusing on simplified systems is that natural insect communities are typically very diverse, and understanding how species interact within biological networks can become very complicated.</p>
<p>Network analysis is a useful tool for studying how agents – for example, people, websites, etc – within a complex network interact to affect certain processes, such as how information is disseminated through social groups. This approach to understanding large networks may also have applications in understanding how biological networks produce a desired service, in our case pest management.</p>
<p>Corn is currently the most intensively produced crop in North America, with approximately 5% of the land surface of the continental United States devoted to this single plant species. Because of its high value, substantial resources – approximately US$3.2 billion in 2013, according to the <a href="http://www.nass.usda.gov/Statistics_by_Subject/">National Agricultural Statistics Service</a> – are spent annually on controlling pests like corn rootworms, European corn borers and other caterpillars and aphids. <a href="http://onlinelibrary.wiley.com/doi/10.1111/mec.12700/abstract">Research</a> has shown that diversity seems important in keeping these pests in check, but what particular attributes of an entire biological network contribute to pest management have not been well-explored.</p>
<h2>Insect communities</h2>
<p>We sampled 53 corn farms across the Northern Great Plains, on the western edge of corn production in the US. </p>
<p>In each field, we identified all insect species (“insects” being defined as all animals with more than four legs and fewer than two legs) in the plant foliage when they shed pollen. This time in the corn’s life cycle is when insect communities are most abundant, and this time of year all major pests co-occur. And we made sure that insecticides or GM crops that might influence corn insect communities were not used in these fields. We identified relative numbers of 106 taxonomic groups of insects on these farms.</p>
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<a href="https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/90365/original/image-20150730-25781-v3vy7o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Researchers examined more than 37,000 specimens to determine the insect communities in 53 maize fields across the Northern Great Plains.</span>
<span class="attribution"><span class="source">Jonathan Lundgren</span>, <span class="license">Author provided</span></span>
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<p>In our analysis, we found that more biodiverse cornfields had fewer pests. More specifically, cornfields with high species diversity and a more even distribution in species abundances had fewer pests.</p>
<p>Interestingly, the number of species and the abundance of individual insects in a cornfield were not correlated with pest density.</p>
<p>What this means is that it isn’t species richness and abundance within a community that is correlated with pest abundance. But rather, it’s the balance of species within these communities that seems to be tied to lower pest populations.</p>
<p>Next, we grouped the cornfields based on how many pests we found. We created a network for each of the insect communities that we found at each separate pest density. These networks are based on the relative abundances of the insects in the community; if the abundance of two species were significantly correlated with one another, we drew a link between these species. It’s a new approach to analyzing the biodiversity of ecological networks.</p>
<h2>Money saver</h2>
<p>We found that communities with stronger networks – that is, more linked species – had fewer pests. Not only this, but network centrality was important; communities with several groups of highly linked species, including insects that prey on others, don’t have the pest problems that loosely linked networks have. Thus, in addition to species diversity, the strength of interactions among species within a community seem to be related to when and where pest outbreaks occur.</p>
<p>This research suggests that practices that reduce diversity in cornfields will aggravate pest problems over time. Unnecessary pesticide inputs and simplification of agroecosystems are destined to require even more pesticides to replace the lost functions of biodiversity and maintain these food production systems.</p>
<p>More importantly, our data suggest that designing cropping systems with high diversity will require fewer insecticide inputs and will save farmers money.</p>
<p>Pieces to this puzzle are already in place: we know that reducing soil disturbance, increasing crop rotation diversity, and including cover crops are important in reducing pests. But we don’t always have a complete picture of how these practices work to reduce pests.</p>
<p>Long-term food security is contingent on inventing production systems that are resilient to stressors like pests. Biodiversity within food systems provides quantifiable and valuable services to society, of which pest management is one.</p><img src="https://counter.theconversation.com/content/45477/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jonathan Lundgren currently receives funding from USDA NIFA. All funding is the result of a competitive grant application process. Dr. Jonathan Lundgren has previously sold predatory beetles to Monsanto Company for their safety testing of GM crops.</span></em></p><p class="fine-print"><em><span>Scott Fausti has received funding from USDA NIFA, and the National Honey Board in the past. All funding was the result of the competitive grant application process. Dr. Fausti has not received any funding or as a financial interest that would be considered a conflict of interest with this published research. </span></em></p>Continued use of pesticides will lower diversity of beneficial insects, costing corn farmers more money over time.Jonathan Lundgren, Research Entomologist, South Dakota State UniversityScott Fausti, Professor, South Dakota State UniversityLicensed as Creative Commons – attribution, no derivatives.