tag:theconversation.com,2011:/nz/topics/yellowstone-national-park-2916/articlesYellowstone National Park – The Conversation2024-01-10T13:28:16Ztag:theconversation.com,2011:article/2202102024-01-10T13:28:16Z2024-01-10T13:28:16ZAfter an 80-year absence, gray wolves have returned to Colorado − here’s how the reintroduction of this apex predator will affect prey and plants<figure><img src="https://images.theconversation.com/files/568700/original/file-20240110-15-dlhj3q.jpg?ixlib=rb-1.1.0&rect=0%2C13%2C4500%2C2991&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A wild gray wolf at Yellowstone National Park near Mammoth Hot Springs, Montana.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/grey-wolf-looking-at-camera-in-yellowstone-national-royalty-free-image/1442648293?phrase=gray+wolf&adppopup=true">John Morrison/iStock via Getty Images Plus</a></span></figcaption></figure><p><em>Gray wolves were <a href="https://www.cbsnews.com/colorado/news/gray-wolves-captured-oregon-reside-colorado-western-slope-reintroduction-plan/">reintroduced to Colorado in December 2023</a>, the latest attempt in a decadeslong effort to build up wolf populations in the Rocky Mountain states. SciLine interviewed <a href="https://www.joannalambert.com">Joanna Lambert</a>, professor of wildlife ecology and director of the American Canid Project at the University of Colorado Boulder, who discussed how and why gray wolf populations declined in the U.S. and the value of reintroducing them to ecosystems in the West.</em></p>
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<figcaption><span class="caption">Dr. Joanna Lambert discusses the gray wolf restoration campaign.</span></figcaption>
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<p><em>Below are some highlights from the discussion. Answers have been edited for brevity and clarity.</em></p>
<p><strong>How can protecting gray wolf populations affect ecosystems?</strong></p>
<p><strong>Joanna Lambert:</strong> <a href="https://www.futurity.org/apex-predators-1178452/">Apex predators</a>, and predators in general, are disappearing from <a href="https://www.fws.gov/initiative/protecting-wildlife/gray-wolf-recovery-news-and-updates">landscapes around the planet</a>. </p>
<p>Without apex predators, their prey species can become overly abundant. But when apex predators are reintroduced, prey populations decrease and vegetation can rebound. So in certain habitats of <a href="https://www.nps.gov/yell/index.htm">Yellowstone National Park</a>, plant species such as willow and aspen are now in greater abundance since wolves were reintroduced in the 1990s. This denser vegetation can provide nesting areas for certain bird species and ideal conditions for beavers to set up dams, which can shift the hydrology of rivers and streams. </p>
<p>In Yellowstone, these effects are localized. Keep in mind that the reintroduction of wolves into Colorado covers a huge area, around <a href="https://www.npr.org/2023/12/19/1220210851/gray-wolves-reintroduced-to-colorado-80-years-after-they-were-eradicated-in-the-#:">22 million acres of public lands</a>, and there aren’t going to be that many wolves introduced – probably 30 or 50 over the next three to five years. So in Colorado, too, effects on vegetation and total numbers of prey species like elk are likely to be localized, diffuse and only within certain microhabitats.</p>
<p><strong>What is special about the reintroduction in Colorado?</strong></p>
<p><strong>Joanna Lambert:</strong> This is the first time an endangered species will be managed and reintroduced into a former range by an entity other than the U.S. Fish and Wildlife. Instead, this reintroduction will be <a href="https://coloradooutdoorsmag.com/2023/12/19/wolf-update-cpw-successfully-releases-gray-wolves/#:">handled by Colorado Parks and Wildlife</a>. This in itself is truly historical and groundbreaking. Instead of being a federal level initiative, this was the result of a citizen-led ballot initiative – Proposition 114 – that was <a href="https://ballotpedia.org/Colorado_Proposition_114,_Gray_Wolf_Reintroduction_Initiative_(2020)">voted into law as of November 2020</a>.</p>
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Read more:
<a href="https://theconversation.com/will-colorado-bring-back-wolves-its-up-to-voters-147244">Will Colorado bring back wolves? It's up to voters</a>
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<p><strong>How were the wolves reintroduced to the area?</strong> </p>
<p><strong>Joanna Lambert:</strong> Those wolves were darted and immobilized in Oregon by expert marksmen and biologists working from a helicopter. They were netted and then brought onto small planes and eventually transported to vehicles, which took them to the regions where they were released. Those animals are radio collared and will be monitored carefully over months and years. The Colorado Parks and Wildlife <a href="https://kdvr.com/news/local/10-wolves-released-so-far-in-colorado-reintroduction-effort/">aim to release 10-15 wolves this winter</a>. </p>
<p><strong>How have gray wolf populations changed in the U.S. over time?</strong> </p>
<p><strong>Joanna Lambert:</strong> Before the arrival of Western settlers over 400-plus years ago, scientists estimate the total number of gray wolves roaming the North American continent was maybe between <a href="https://www.biologicaldiversity.org/campaigns/gray_wolves/">500,000 to 2 million</a>.</p>
<p>By the time we get to the mid-1960s, only roughly 200 to 400 breeding pairs of <a href="https://westernlandsblog.arizona.edu/uncertain-future-gray-wolves#:%7E">gray wolves lived in the lower 48</a>. This is largely a consequence of a concerted effort on the part of multiple legislative entities – local, regional, state and federal – to remove predators. Reducing the number of wolves through hunting, shooting, trapping and poisoning was extremely effective.</p>
<p>The numbers of gray wolves plummeted throughout the 20th century so that we only have a handful around by the time the <a href="https://www.fws.gov/program/endangered-species/species">Endangered Species Act</a> was signed into law in 1973. Gray wolves were one of the very first mammal species to be put onto the endangered species list in 1974. </p>
<p>The number of gray wolves has increased throughout the United States but are concentrated in two populations. One is in the upper Midwest region, in Minnesota, Wisconsin and Michigan, where there are probably about 4,500 wolves. </p>
<p>In the Northern Rockies, and that includes the states of Idaho, Wyoming, Montana, eastern Oregon and eastern Washington, we probably have somewhere around 2,500 to 3,000 wolves. These wolves are largely a consequence of the reintroductions that took place in Idaho and in Yellowstone in the mid-1990s.</p>
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<figcaption><span class="caption">The dramatic release happened 80 years after gray wolves were eradicated from the state.</span></figcaption>
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<p><strong>How can humans coexist with gray wolves?</strong></p>
<p><strong>Joanna Lambert:</strong> Up until around 100 years ago, humans had been coexisting and living alongside gray wolves for thousands of years, so we do have the knowledge on how to coexist with predators. We are now at a point where that information and that knowledge has to be relearned. </p>
<p>That can include any number of <a href="https://wdfw.wa.gov/species-habitats/at-risk/species-recovery/gray-wolf/conflict-prevention#:%7E">scare devices or hazing tactics</a> that can be used with both livestock and predators. It can include range riders working to make sure that they know where the wolves are. Ranchers can make changes in how animals are herded up and moved. Making these changes will take time, but Colorado Parks and Wildlife will be involved in those conversations and in the training of ranchers on how to keep their livestock safe. A number of nonprofits will also be involved in educating the public.</p>
<p><strong>How does this reintroduction fit into the global extinction crisis?</strong> </p>
<p><strong>Joanna Lambert:</strong> We are living in what many experts describe as <a href="https://www.cnn.com/2020/06/01/world/sixth-mass-extinction-accelerating-intl/index.html">the sixth extinction</a> and are on the verge of losing upwards of <a href="https://www.reuters.com/lifestyle/science/extinction-crisis-puts-1-million-species-brink-2022-12-23/">a million species in the next couple of decades</a>. Conservation biologists and practitioners around the world are working to offset this massive extinction. Reintroduction of important keystone species like gray wolves is one tool that can help. </p>
<p><em>Watch the <a href="https://www.sciline.org/life-sciences/gray-wolf-reintroduction/">full interview</a> to hear more.</em></p>
<p><em><a href="https://www.sciline.org/">SciLine</a> is a free service based at the nonprofit American Association for the Advancement of Science that helps journalists include scientific evidence and experts in their news stories.</em></p><img src="https://counter.theconversation.com/content/220210/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joanna Lambert 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>At one time, perhaps as many as 2 million gray wolves roamed the North American continent. But now those numbers are down to a few thousand.Joanna Lambert, Professor of Environmental Studies and Faculty in Ecology and Evolutionary Biology, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1994512023-02-17T12:09:58Z2023-02-17T12:09:58ZReintroducing top predators to the wild is risky but necessary – here’s how we can ensure they survive<figure><img src="https://images.theconversation.com/files/509239/original/file-20230209-20-7c87m0.png?ixlib=rb-1.1.0&rect=5%2C0%2C1272%2C848&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Collared leopard being released into North Ossetia, Russia in 2022.</span> <span class="attribution"><span class="source">Pavel Padalko</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Large carnivores are critical to the balance of an ecosystem. In Yellowstone National Park in the western US, <a href="https://www.nwf.org/Educational-Resources/Wildlife-Guide/Mammals/Gray-Wolf">grey wolves</a> keep elk populations at a <a href="https://www.sciencedirect.com/science/article/abs/pii/S0006320711004046">healthy level</a>. This prevents vegetation from being overgrazed and leads to taller woody plants which allow other species, such as beavers, to flourish. </p>
<p>But habitat loss and persecution have <a href="https://www.science.org/doi/full/10.1126/science.1241484">eliminated</a> many large carnivores from their historical environment. The Eurasian lynx could be found in the UK over a thousand years ago and wolves roamed the country until the mid-18th century.</p>
<p>However, our attitudes towards these animals are gradually changing and large carnivores are now viewed by many as the <a href="https://www.science.org/doi/full/10.1126/science.1257553">victims of human expansion</a>. Many areas are seeing these animals return as a result. Yellowstone’s grey wolves were reintroduced in 1995 after 70 years, and in 2020, voters approved <a href="https://www.cpr.org/2022/09/09/where-colorado-will-reintroduce-wolves/">the species’ reintroduction</a> to the state of Colorado.</p>
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<p>Like these wolves, many other species require human intervention to reach their former habitats. But this is costly, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/rec.13243">controversial</a> and often ends in failure. The relocation of a single animal can <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105042">cost thousands</a> and once released, these animals can <a href="https://conbio.onlinelibrary.wiley.com/doi/abs/10.1111/COBI.12959">prey on local livestock</a>.</p>
<p>But since 2007, we’ve seen <a href="https://www.sciencedirect.com/science/article/abs/pii/S1877343520300592">technological advances</a> in wildlife monitoring, <a href="https://portals.iucn.org/library/efiles/documents/2013-009.pdf">improved guidelines</a> for carrying out reintroductions and the global <a href="https://rewildingeurope.com/">rewilding movement</a> gathering pace.</p>
<p>These factors make now the perfect moment to determine whether carnivore reintroductions are becoming more effective. In a <a href="https://doi.org/10.1016/j.biocon.2023.109909">new study</a>, my colleagues and I studied the success of almost 300 carnivore reintroductions worldwide involving 18 different species between 2007 and 2021.</p>
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<a href="https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Four maps split by continent showing the locations of the reintroductions studied." src="https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=622&fit=crop&dpr=1 600w, https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=622&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=622&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=781&fit=crop&dpr=1 754w, https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=781&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/510538/original/file-20230216-24-2tr9vv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=781&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Global distribution of the large carnivore reintroductions studied.</span>
<span class="attribution"><a class="source" href="https://creativecommons.org/licenses/by/4.0/">Thomas et al (2023)</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<h2>Indicators of success</h2>
<p>Between 2007 and 2021, 66% of all the reintroduced carnivores studied were still alive six months later. Survival at the six month mark was our measure of success.</p>
<p>Success rates for wild-born carnivores increased from 53% to 70%, while twice the number of captive-born animals (64%) now survive reintroduction than did so in 2007. </p>
<p>The most successful species in our study were <a href="https://www.britannica.com/animal/maned-wolf">maned wolves</a>, <a href="https://www.britannica.com/animal/puma-mammal-species">pumas</a> and <a href="https://www.nationalgeographic.com/animals/mammals/facts/ocelot">ocelots</a>. In contrast, <a href="https://www.britannica.com/animal/lion">lions</a>, <a href="https://www.britannica.com/animal/brown-hyena">brown hyenas</a>, <a href="https://www.britannica.com/animal/cheetah-mammal">cheetahs</a>, <a href="https://wildcatconservation.org/wild-cats/eurasia/iberian-lynx/">Iberian lynx</a> and grey wolves were least able to survive their new environment.</p>
<p>We tested various factors, all of which were under the project manager’s control, that influence the success of animal reintroductions – practical changes that could improve the outcome of future rewilding efforts.</p>
<p>So-called “soft releases”, where animals are allowed an acclimation period at the release site anywhere between <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105042">10 days and 5 months</a> long, had a clear influence on survival. These releases had an 82% success rate compared to just 60% for releases with no period of adjustment.</p>
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<img alt="A puma walking next to a chain fence in a forested area." src="https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=432&fit=crop&dpr=1 600w, https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=432&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=432&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=543&fit=crop&dpr=1 754w, https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=543&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/509635/original/file-20230213-14-2o3a7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=543&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A puma in a pre-release enclosure before being released into Serra do Japi, São Paulo, Brazil.</span>
<span class="attribution"><span class="source">Associação Mata Ciliar</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>Younger animals and those born in the wild were also more likely to survive reintroduction. Wild-born animals had a 72% survival rate compared to 64% for animals born in captivity. This is good news for rehabilitated and orphaned carnivores which are taken from the wild for their survival. These animals represent a sizeable proportion of all reintroduced carnivores and made up 22% of the animals in our study. </p>
<p>We found higher success rates when carnivores were released into unfenced areas. This is surprising as <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.12091">research</a> finds that fenced nature reserves tend to support higher densities of carnivores and reduce conflict with humans. </p>
<p>But greater competition for resources and direct conflict with other carnivores in these reserves may have a negative impact on the survival of reintroduced animals. <a href="https://www.tandfonline.com/doi/abs/10.1080/15627020.2003.11657196">Research</a> on the range and movement patterns of <a href="https://en.wikipedia.org/wiki/African_wild_dog">African wild dogs</a> in South Africa’s fenced Pilanesberg National Park found that the dogs actively avoid interaction with lions.</p>
<h2>Rewilding on the horizon – but there’s a catch</h2>
<p>Large carnivore reintroductions are becoming more effective, prompting countries to consider reintroducing large predators. In the UK, debates are ongoing surrounding the possible <a href="https://www.taylorfrancis.com/chapters/edit/10.4324/9781315175454-6/community-divided-steven-lipscombe-chris-white-adam-eagle-erwin-van-maanen">reintroduction of the Eurasian lynx</a>. Our findings could help inform their release. </p>
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Read more:
<a href="https://theconversation.com/eurasian-lynx-how-our-computer-model-highlighted-the-best-site-for-restoring-this-wild-cat-to-scotland-113624">Eurasian lynx: how our computer model highlighted the best site for restoring this wild cat to Scotland</a>
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<p>But our research also highlights the alarming fact that one-third of all large carnivore reintroductions fail. And even when successful, the establishment of a population has proved a challenge. Just 37% of the animals that survived reintroduction successfully reproduced and the number of animals who will have raised young to adulthood is likely even lower. It seems that many rewilded animals take far longer than six months to establish themselves in an ecosystem and find a potential mate.</p>
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<img alt="A lynx being released into the wild." src="https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/509639/original/file-20230213-27-ffpb1e.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">
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<span class="caption">A male lynx was released together with two female lynx in the Slovenian Alps in 2021.</span>
<span class="attribution"><span class="source">Polona Bartol</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>Preventing species loss in their current ranges should thus always take priority. This will involve measures to tackle urbanisation and climate change, which are at present two leading causes of global habitat loss. </p>
<p>Despite their increasing success, the reintroduction of large carnivores still leads to the death of many of the animals involved and often fails to establish a population. The risky nature of these interventions makes it even more important that they have local support or they are likely doomed to fail from the start.</p><img src="https://counter.theconversation.com/content/199451/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Seth Thomas does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research studies the factors that determine whether large carnivore reintroductions will be a success.Seth Thomas, Research assistant, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1981452023-02-02T13:34:46Z2023-02-02T13:34:46ZThe world’s first environmental clean-up happened 400 million years ago<p>One of the biggest environmental challenges today is to treat land that is contaminated by toxic elements from industrial activity, elements like <a href="https://www.gov.uk/government/publications/arsenic-properties-incident-management-and-toxicology/arsenic-general-information">arsenic</a>, <a href="https://www.usgs.gov/centers/national-minerals-information-center/antimony-statistics-and-information">antimony</a> and <a href="https://www.rsc.org/periodic-table/element/74/tungsten">tungsten</a>.</p>
<p>But these same elements can be brought to the Earth’s surface by natural processes such as the bubbling up of <a href="https://www.britannica.com/science/hot-spring">hot springs</a>. So it is valuable to understand how they were dealt with by the environment before humans came along. A site in Aberdeenshire in Scotland which is famous for early fossil life preserved by hot springs, shows us how it could have happened. </p>
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<img alt="A round cross section of a fossilised plant stem detailed in cream and brown." src="https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=584&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=584&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=584&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=734&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=734&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505725/original/file-20230122-49501-wrokic.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=734&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A cross-section of a stem preserved as a silica petrifaction, detailing its cellular structure, found at Rhynie, Aberdeenshire.</span>
<span class="attribution"><a class="source" href="https://www.wikiwand.com/en/Paleobotany#Media/File:Rhynia_stem.jpg">Wikiwand</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Some of the world’s <a href="https://www.abdn.ac.uk/geosciences/departments/geology/what-is-the-rhynie-chert-1892.php">most well preserved fossilised plants</a> are found in <a href="https://www.google.com/maps/dir//Rhynie,+Huntly+AB54+4GJ/@57.4217189,-3.8006635,8.2z/data=!4m9!4m8!1m0!1m5!1m1!1s0x48844b525cd28473:0x42651503db9b8f55!2m2!1d-2.835357!2d57.333126!3e0">Rhynie</a>, just west of Aberdeen, in deposits thought to have come from the world’s oldest land ecosystem. </p>
<p>Exquisitely detailed plants – as well as spiders, insects, fungi and other life – were preserved there by hot springs about 410 million years ago. These are some of the earliest fossilised plants known, so are important in what they can tell us about plant evolution.</p>
<p>But those hot springs also introduced elements that would have been toxic to most forms of life. Our latest <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GC010647">research</a> shows how minerals deposited among the plants extracted the toxic metals from the spring water and limited their impact on the environment.</p>
<h2>Minerals and toxic metals</h2>
<p>The plants at Rhynie were encased in the mineral <a href="https://www.britannica.com/science/silica">silica</a>, which deposits around hot springs. At tourist spots like <a href="https://homepages.see.leeds.ac.uk/%7Eearlgb/Publications/Tobler%20et%20al%20Iceland%20geochem_Geobiology.pdf">Iceland</a>, <a href="https://www.nzgeo.com/stories/the-living-crystals-of-dead-geysers/#:%7E:text=of%20New%20Zealand's%20thermal%20centres,water%20discharges%20at%20the%20surface.">New Zealand</a> and <a href="https://www.sciencedirect.com/science/article/abs/pii/S0377027321002201">Yellowstone National Park</a> in the US, bacteria in the water are involved in producing these silica deposits, and this would have been the same at Rhynie.</p>
<p>As well as silica, the fossils contain certain minerals including <a href="https://geology.com/minerals/pyrite.shtml">pyrite</a> (iron sulphide, so-called fool’s gold), <a href="https://www.pnas.org/doi/10.1073/pnas.96.7.3447#:%7E:text=Mn%20oxides%20are%20the%20predominant,migration%20and%20reprecipitation%20(4).">manganese oxides</a> and <a href="https://www.sciencedirect.com/science/article/pii/B9780815515784500123">titanium oxides</a>. It’s these minerals, produced by the bacteria and other lifeforms, that would have soaked up the toxic metals. </p>
<p>Pyrite, formed by the bacteria, soaked up arsenic from the spring water. Manganese oxides, <a href="http://awarticles.s3.amazonaws.com/22591055.pdf">commonly deposited by fungi</a>, also absorbed arsenic. Titanium oxides, formed particularly around decomposing plant remains, absorbed tungsten and antimony. </p>
<p>So between them, the minerals formed by biological activity accounted for the main sources of toxicity. The evidence from Rhynie shows how natural processes have helped clean the environment since life first colonised the land.</p>
<h2>The magic of mushrooms</h2>
<p>Our solutions to man-made environmental problems, such as contamination from industry and mining, typically include a range of <a href="https://www.pollutionsolutions-online.com/news/soil-remediation/18/breaking-news/which-chemicals-are-used-for-soil-treatment/58235">chemical treatments</a>. But an exciting “natural” approach is the technique of <a href="https://www.ffungi.org/why-fungi/mycoremediation">mycoremediation</a>, where fungi concentrate and store contaminating elements in their substance. </p>
<p>Fungi can be very resilient, and adapt rapidly to substances we regard as toxic. One strategy is to harvest fungi that live on mining or industrial waste and which are predisposed to cope with it, then use the fungi to clean up waste on other problem sites. In this way, fungi can be used to recover land contaminated by harmful metals.</p>
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<p>Biologist <a href="https://www.merlinsheldrake.com/">Merlin Sheldrake</a>, in his award-winning 2020 book <a href="https://www.merlinsheldrake.com/entangled-life">Entangled Life</a>, argues: “Fungi are some of the best-qualified organisms for environmental remediation … fine-tuned over a billion years of evolution.”</p>
<p>Evolution is a key word here. The ecosystem (plants, animals and their habitat, including minerals) does not “intend” to clean up toxic chemicals as humans do. However, life is more likely to thrive and reproduce in ecosystems that strip out harmful substances. Just as particular fungi can be <a href="https://www.ffungi.org/why-fungi/mycoremediation">selected</a> to help deal with contaminated land, evolution favoured the species that adapted to environmental changes in the geological past, as implied at Rhynie.</p>
<h2>Remaining questions</h2>
<p>The deposits at this special geological site were formed by hot springs, whose waters preserved the plant cells. But because the hot springs that formed the Rhynie deposit were rich in arsenic, antimony and other trace elements, there is uncertainty about how representative these fossils may be of early plant communities.</p>
<p>Scientists <a href="https://www.jstor.org/stable/pdf/4142659.pdf">might argue</a>
that the plants found at Rhynie could be an adaptation to an environment that was chemically unusual. There is no clear answer to whether this was so, but our observations do suggest that the ecosystem was able to respond to the water chemistry, so the existence of these plants was not necessarily abnormal.</p>
<p>Visitors to hot springs in New Zealand and Yellowstone today can see orange and yellow crusts containing the harmful arsenic, antimony and so on, but also precious metals like gold and silver, so the springs attract commercial interest. </p>
<p>Hot springs worldwide also contain an element that was pretty much ignored until recently: <a href="https://www.rsc.org/periodic-table/element/3/lithium">lithium</a>. The spring waters provide a renewable supply of this element which is currently fundamental to rechargeable batteries – especially in electric vehicles, which are essential in the quest to achieve carbon emission targets. So hot springs may have more than one role in helping clean up the environment.</p>
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<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">
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<p class="fine-print"><em><span>John Parnell receives funding from NERC. </span></em></p>When it comes to cleaning up land contaminated by toxic waste, we can follow nature’s example before humans populated the earth.John Parnell, Professor of Geology and Petroleum Geology, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1895242022-09-22T19:51:23Z2022-09-22T19:51:23ZWe can use drones to get inside and learn more about active, gassy volcanoes<figure><img src="https://images.theconversation.com/files/485137/original/file-20220916-1799-a2tkgw.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5208%2C3875&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An overhead shot of a volcano crater in east Java, Indonesia.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Volcanic eruptions cannot be predicted with 100 per cent certainty. However, details about an upcoming eruption can be estimated using the hot and smelly gases a volcano produces. </p>
<p>These gases provide clues about the timing, duration or severity of upcoming eruptions which can help local authorities decide if and when the surrounding communities need to be evacuated. </p>
<p>On average, there are <a href="https://volcano.si.edu/">up to 50 volcanoes</a> actively erupting on the planet at any given time. Many of these volcanoes are more likely to be spewing hot gases — like steam and carbon dioxide — than lava. Collecting these gases is key to understanding the mysterious ways of volcanoes, but it can be dangerous.</p>
<p>Now, <a href="https://doi.org/10.30909/vol.03.01.67114">drones are making it safer</a> and easier than ever before.</p>
<h2>Gassy volcanoes</h2>
<p>For the better part of the last decade, I have been visiting such gassy volcanoes regularly to catch them just before, during or after an eruption. </p>
<p>I have worked with other scientists and engineers to <a href="https://eos.org/science-updates/drones-swoop-in-to-measure-gas-belched-from-volcanoes">measure volcanic gases</a> with a variety of devices attached to drones. </p>
<p>Our latest research uses drones to <a href="https://doi.org/10.1016/j.jvolgeores.2022.107639">capture volcanic carbon dioxide at Poás volcano in Costa Rica</a>. We measured the isotopes of carbon in this carbon dioxide and discovered a pattern in the way these chemical fingerprints change during different stages of activity.</p>
<h2>Unique carbon makeup</h2>
<p>Carbon dioxide is everywhere: in the air we exhale, in vehicle exhaust — and dissolved in magma. At volcanoes, it escapes from magma to the surface through cracks and hydrothermal systems (like the geysers in Yellowstone National Park), by seeping through the soil or by puffing out in a plume of gas. </p>
<p>By obtaining a sample of this <a href="https://doi.org/10.2138/rmg.2013.75.11">volcanic carbon</a>, we can measure the stable carbon isotopic ratio, a unique chemical makeup which reflects the source and pathway the CO2 took to the surface. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a plume of smoke emerges from a hole in the ground" src="https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485139/original/file-20220916-8280-bzy2aj.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">Underground pressure forces gas and smoke out of the ground in the geysers in Yellowstone National Park.</span>
<span class="attribution"><span class="source">(Donna Elliot/Unsplash)</span></span>
</figcaption>
</figure>
<p>Each volcano around the world produces a unique range of these <a href="https://doi.org/10.1126/science.aan5049">carbon isotopes</a> which change when the volcanic system changes. </p>
<p>However, it took a long time to collect each sample when researchers needed to hike down into a crater, putting them at risk each second they remained in the danger zone. With the evolution of unoccupied aerial systems (UAS, also known as drones), researchers have started sending these machines into the danger areas.</p>
<h2>Employing drones</h2>
<p>To do this, we used switches and electronics parts to connect gas sensors to the onboard communications systems of the UAS. The volcanic CO2 would be sucked in through a series of tubing with the help of a pump and sensors that would send a signal back to the pilot when we entered the gas plume. With the flick of a switch on the remote control, the pilot could choose — from a safe distance — when and where to collect the gas sample. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4898%2C3226&q=45&auto=format&w=1000&fit=clip"><img alt="A drone landed in front of smoke" src="https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4898%2C3226&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484123/original/file-20220912-1707-5fe5og.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A drone equipped to sample volcanic gas captures carbon dioxide.</span>
<span class="attribution"><span class="source">(Fiona D'Arcy)</span>, <span class="license">Author provided</span></span>
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</figure>
<p>We arrived in Costa Rica in April 2019 with our shiny new drone set-up, which we launched at the rim of Poás volcano and which crashed almost immediately. Thankfully, our team whipped up a quick solution for our second drone — a pump and switch hanging from the drone in a laundry bag. It worked flawlessly.</p>
<p>To avoid further losses, we got up close to the crater and flew our assembly directly above it. Later that day, we looked at the stable isotopes of carbon in our drone samples and in the samples we took from the ground. After we accounted for the mixing with the regular air in the drone samples, the two results were strikingly similar. Our drone assembly worked!</p>
<h2>A pattern emerges</h2>
<p>When we started compiling our data with all the carbon isotopes measured at Poás volcano in the past, we noticed a trend in how the balance of isotopes shifted when the volcano was behaving differently. </p>
<p>During eruptive phases, when Poás was making wet explosions releasing extra hot, sulfur-rich gas, the isotopes of carbon slipped down to lighter values. Meanwhile, during quieter phases <a href="https://doi.org/10.1016/j.jvolgeores.2021.107297">when the volcano was sealed</a>, the isotopic balance rose to heavier values. </p>
<p>With this new insight, we could look back even further and stitch together our data with <a href="https://doi.org/10.1007/978-3-319-02156-0_10">isotope data from older activity</a>. We saw that this pattern was repeating itself, with the carbon isotopes alternating between heavy an light values over the last 20 years of activity at Poás. There were relatively heavy values when the volcano was sealed and there were relatively light values when the volcano was open. </p>
<p>We now have a blueprint of what warning signals to look for in future isotopes of carbon sampled at this volcano when it’s gearing up to erupt.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1298020478691549190"}"></div></p>
<h2>Future research</h2>
<p>Thanks to drones, we captured the first CO2 from Poás volcano since 2014. Volcanic gases sampled before our work were all taken by hand by brave volcano scientists climbing down into the crater of Poás. These expeditions were few and far between. </p>
<p>We hope that with the onset of gas-capturing drones, carbon dioxide at volcanoes <a href="https://doi.org/10.1126/sciadv.abb9103">can start to be sampled more frequently</a>. This will fill the gaps in the timeline and help us understand and forecast eruptions.</p><img src="https://counter.theconversation.com/content/189524/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona D'Arcy receives funding from the Vanier Canada Graduate Scholarships (Vanier CGS). </span></em></p>Drones can be used to collect gas samples from active volcanoes, where it is too dangerous for researchers. This data can be then used to predict the frequency and severity of eruptions.Fiona D'Arcy, PhD candidate in Earth Sciences, McGill UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1853642022-07-05T12:14:47Z2022-07-05T12:14:47ZClimate change is making flooding worse: 3 reasons the world is seeing more record-breaking deluges and flash floods<figure><img src="https://images.theconversation.com/files/471429/original/file-20220628-14613-2mjpl2.jpg?ixlib=rb-1.1.0&rect=0%2C37%2C3134%2C2056&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fast-moving floodwater obliterated sections of major roads through Yellowstone National Park in 2022.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/yellowstonenps/52167350392">Jacob W. Frank/National Park Service</a></span></figcaption></figure><p>Heavy rain combined with melting snow can be a destructive combination. </p>
<p>In June 2022, storms dumped up to 5 inches of rain over three days in the mountains in and around Yellowstone National Park, rapidly melting snowpack. As the rain and meltwater poured into creeks and then rivers, it became a flood that damaged roads, cabins and utilities and <a href="https://apnews.com/article/floods-travel-montana-obituaries-evacuations-3753caa39435d9f3f45d8b582381a0c6">forced more than 10,000 people to evacuate</a>.</p>
<p>The Yellowstone River shattered its previous record and reached its highest water levels recorded since monitoring began almost 100 years ago.</p>
<p>Although floods are a natural occurrence, human-caused climate change is <a href="https://www.gyclimate.org/">making severe flooding events like these more common</a>. I study how climate change affects hydrology and flooding. In mountainous regions, three effects of climate change in particular are creating higher flood risks: more intense precipitation, shifting snow and rain patterns and the effects of wildfires on the landscape.</p>
<h2>Warmer air leads to more intense precipitation</h2>
<p>One effect of climate change is that a <a href="https://www.epa.gov/climate-indicators/climate-change-indicators-heavy-precipitation">warmer atmosphere creates more intense precipitation events</a>. </p>
<p>This occurs because warmer air can hold more moisture. The amount of water vapor that the atmosphere can contain increases by <a href="https://doi.org/10.1038/nclimate1452">about 7% for every 1.8 degrees Fahrenheit</a> (1 degree Celsius) of increase in atmospheric temperature.</p>
<p>Research has documented that this <a href="https://doi.org/10.1029/2018WR024067">increase in extreme precipitation is already occurring</a>, not only in regions like Yellowstone, but <a href="https://theconversation.com/global-evidence-links-rise-in-extreme-precipitation-to-human-driven-climate-change-163715">around the globe</a>. The fact that the world has experienced multiple record flooding events in recent years – including catastrophic <a href="https://www.bbc.com/news/world-australia-61991112">flooding in</a> <a href="http://www.bom.gov.au/climate/enso/wrap-up/archive/20220705.archive.shtml">Australia</a>, <a href="https://www.science.org/content/article/europe-s-deadly-floods-leave-scientists-stunned">Western Europe</a> <a href="https://weather.com/en-IN/india/monsoon/news/2022-07-12-around-1k-rescued-from-gujarat-floods-heavy-rains-to-continue">India</a> and <a href="https://www.washingtonpost.com/weather/2021/07/21/zhengzhou-china-record-rain-flooding/">China</a> – is not a coincidence. Climate change is making record-breaking extreme precipitation more likely.</p>
<figure class="align-center ">
<img alt="A woman with work gloves and clothing covered in mud walks through a muddy residential street filled with mud-covered furniture and other damaged belongings people are throwing out after a flood." src="https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471466/original/file-20220628-16342-auzmdw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Extreme rain storms triggered flooding and mudslides in Western Europe in July 2021, killing more than 200 people.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/volunteers-and-residents-start-the-clean-up-process-at-news-photo/1329350141?adppopup=true">Thomas Lohnes/Getty Images</a></span>
</figcaption>
</figure>
<p><iframe id="zBAAz" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/zBAAz/5/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The latest <a href="https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/">assessment report</a> published by the Intergovernmental Panel on Climate Change shows how this pattern will continue in the future as global temperatures continue to rise.</p>
<h2>More precipitation falling as rain</h2>
<p>In colder areas, especially mountainous or high-latitude regions, climate change affects flooding in additional ways. </p>
<p>In these regions, many of the largest historical <a href="https://doi.org/10.1002/2016GL068070">floods have been caused by snowmelt</a>. However, with warmer winters due to climate change, <a href="https://www.climatecentral.org/news/winters-becoming-more-rainy-across-us-20017">less winter precipitation is falling as snow</a>, and more is falling as rain instead.</p>
<p>This shift from snow to rain can have dramatic implications for flooding. While snow typically melts slowly in the late spring or summer, rain creates runoff that flows to rivers more quickly. As a result, research has shown that <a href="https://doi.org/10.1029/2022GL098855">rain-caused floods can be much larger than snowmelt-only floods</a>, and that the shift from snow to rain <a href="https://doi.org/10.1029/2019WR025571">increases overall flood risk</a>.</p>
<p>The transition from snow to rain is already occurring, <a href="https://theconversation.com/yellowstone-is-losing-its-snow-as-the-climate-warms-and-that-means-widespread-problems-for-water-and-wildlife-163223">including in places like Yellowstone National Park</a>. Scientists have also found that <a href="https://doi.org/10.1002/2015WR017784">rain-caused floods are becoming more common</a>. In some locations, the changes in flood risk due to the shift from snow to rain could even be larger than the effect from increased precipitation intensity.</p>
<p><iframe id="O1p7r" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/O1p7r/5/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Changing patterns of rain on snow</h2>
<p>When <a href="https://doi.org/10.1175/BAMS-88-3-319">rain falls on snow</a>, as happened in the recent flooding in Yellowstone, the combination of rain and snowmelt can lead to especially high runoff and flooding.</p>
<p>In some cases, rain-on-snow events occur while the ground is still partially frozen. Soil that is frozen or already saturated can’t absorb additional water, so even more of the rain and snowmelt run off, contributing directly to flooding. This combination of rain, snowmelt and frozen soils was a primary driver of the <a href="https://www.nytimes.com/2019/03/18/us/nebraska-flooding-facts.html">Midwest flooding in March 2019</a> that caused over US$12 billion in damage.</p>
<p>While rain-on-snow events are not a new phenomenon, climate change can shift when and where they occur. Under warmer conditions, <a href="https://doi.org/10.1038/s41558-018-0236-4">rain-on-snow events become more common at high elevations</a>, where they were previously rare. Because of the increases in rainfall intensity and warmer conditions that lead to rapid snowmelt, there is also the possibility of larger rain-on-snow events than these areas have experienced in the past.</p>
<figure class="align-center ">
<img alt="A large two-story building is collapsing after fast-moving water eroded the land under nearly half of it." src="https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471431/original/file-20220628-14648-yhqe7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The 2022 Yellowstone flood inundated communities and swiftly eroded the land beneath this cabin that housed park employees.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/yellowstonenps/52146801150">Gina Riquier via National Park Service</a></span>
</figcaption>
</figure>
<p>In lower-elevation regions, rain-on-snow events may actually become less likely than they have been in the past because of the decrease in snow cover. These areas could still see worsening flood risk, though, because of the increase in heavy downpours.</p>
<h2>Compounding effects of wildfire and flooding</h2>
<p>Changes in flooding are not happening in isolation. Climate change is also exacerbating <a href="https://www.nationalgeographic.com/science/article/climate-change-increases-risk-fires-western-us">wildfires</a>, creating another risk during rainstorms: mudslides. </p>
<p>Burned areas are more <a href="https://doi.org/10.1029/2020EF001735">susceptible to mudslides and debris flows during extreme rain</a>, both because of the lack of vegetation and changes to the soil caused by the fire. In 2018 in Southern California, heavy rain within the boundary of the <a href="https://www.cnn.com/2018/06/02/us/thomas-fire-officially-out/index.html">2017 Thomas Fire</a> caused <a href="https://www.cnn.com/2018/01/11/us/mudslide-slider-california/index.html">major mudslides</a> that destroyed over 100 homes and led to more than 20 deaths. Fire can change the soil in ways that allow <a href="https://doi.org/10.2113/EEG-D-20-00029">less rain to infiltrate into the soil</a>, so more rain ends up in streams and rivers, leading to worse flood conditions.</p>
<figure class="align-center ">
<img alt="Two men point stand on a deck overlooking a neighboring house where mud has flowed through the yard and is mounded half way up the side of the home." src="https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471467/original/file-20220628-14559-d6mcuz.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 2021 rainstorm that hit the denuded landscape of a burn scar sent mud flowing into streets and yards in Silverado, California.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/two-men-survey-the-damage-from-mud-and-debris-that-ran-news-photo/1299356465">Paul Bersebach/MediaNews Group/Orange County Register via Getty Images</a></span>
</figcaption>
</figure>
<p>With the uptick in wildfires due to climate change, more and more areas are exposed to these risks. This combination of wildfires followed by extreme rain will also become <a href="https://doi.org/10.1126/sciadv.abm0320">more frequent in a future with more warming</a>.</p>
<p>Global warming is creating complex changes in our environment, and there is a clear picture that it increases flood risk. As the Yellowstone area and other flood-damaged mountain communities rebuild, they will have to find ways to adapt for a riskier future.</p><img src="https://counter.theconversation.com/content/185364/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Frances Davenport 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>Extreme downpours brought deadly flooding to the Appalachian region, just a few weeks after the destructive Yellowstone River flood.Frances Davenport, Assistant Professor of Civil and Environmental Engineering, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1632232021-06-23T16:01:08Z2021-06-23T16:01:08ZYellowstone is losing its snow as the climate warms, and that means widespread problems for water and wildlife<figure><img src="https://images.theconversation.com/files/407749/original/file-20210622-23-a44xbw.jpg?ixlib=rb-1.1.0&rect=0%2C14%2C3264%2C2428&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Snow melts near the Continental Divide in the Bridger Wilderness Area in Wyoming, part of the Greater Yellowstone Area.</span> <span class="attribution"><span class="source">Bryan Shuman/University of Wyoming</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>When you picture <a href="https://www.nps.gov/yell/index.htm">Yellowstone National Park</a> and its neighbor, <a href="https://www.nps.gov/grte/index.htm">Grand Teton</a>, the snowcapped peaks and <a href="https://www.usgs.gov/center-news/a-time-when-old-faithful-wasn-t-so-faithful">Old Faithful Geyser</a> almost certainly come to mind. Climate change threatens all of these iconic scenes, and its impact reaches far beyond the parks’ borders.</p>
<p>A new <a href="https://gyclimate.org/">assessment of climate change</a> in the two national parks and surrounding forests and ranchland warns of the potential for significant changes as the region continues to heat up.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing the parks and forest land within the Greater Yellowstone Area" src="https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407769/original/file-20210622-28-edp9w6.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">The Greater Yellowstone Area includes both Yellowstone and Grand Teton national parks, as well as surrounding national forests and federal land.</span>
<span class="attribution"><a class="source" href="https://www.nps.gov/articles/assessing-the-ecological-health-of-the-greater-yellowstone-ecosystem.htm">National Park Service</a></span>
</figcaption>
</figure>
<p>Since 1950, average temperatures in the Greater Yellowstone Area have <a href="https://gyclimate.org/">risen 2.3 degrees</a> Fahrenheit (1.3 C), and potentially more importantly, the region has lost a quarter of its annual snowfall. With the region <a href="https://gyclimate.org/">projected to warm 5-6 F by 2061-2080</a>, compared with the average from 1986-2005, and by as much as 10-11 F by the end of the century, the high country around Yellowstone is poised to lose its snow altogether.</p>
<p>The loss of snow there has repercussions for a vast range of ecosystems and wildlife, as well as cities and farms downstream that rely on rivers that start in these mountains.</p>
<h2>Broad impact on wildlife and ecosystems</h2>
<p>The Greater Yellowstone Area comprises <a href="https://www.nps.gov/yell/learn/nature/greater-yellowstone-ecosystem.htm">22 million acres</a> in northwest Wyoming and portions of Montana and Idaho. In addition to geysers and hot springs, it’s home to the southernmost range of grizzly bear populations in North America and <a href="https://www.perc.org/2019/12/06/the-marvelous-migrations-of-greater-yellowstone/">some of the longest intact wildlife migrations</a>, including the seasonal traverses of elk, pronghorn, mule deer and bison.</p>
<p>The area also represents the one point where the three major river basins of the western U.S. converge. The rivers of the Snake-Columbia basin, Green-Colorado basin, and Missouri River Basin all begin as snow on the Continental Divide as it weaves across Yellowstone’s peaks and plateaus.</p>
<figure class="align-center ">
<img alt="A bear and cub walking along a river in Yellowstone National Park." src="https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407775/original/file-20210622-16-11sz5oa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Less water in rivers can harm cutthroat trout, which grizzly bears and other wildlife rely on for food.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/grizzly-bear-mother-and-her-cub-walk-near-pelican-creek-news-photo/153663648">Karen Bleier/AFP via Getty Images</a></span>
</figcaption>
</figure>
<p>How climate change alters the Greater Yellowstone Area is, therefore, a question with implications far beyond the impact on <a href="https://www.nps.gov/yell/learn/nature/yellowstone-cutthroat-trout.htm">Yellowstone’s declining cutthroat trout</a> population and disruptions to the <a href="https://apnews.com/article/wildlife-climate-change-beetles-bears-climate-b847771d0641e961a38c5c72312a53d6">food supplies</a> critical for the region’s recovering grizzly population. By altering the water supply, it also shapes the fate of major Western reservoirs and their dependent cities and farms hundreds of miles downstream. </p>
<p>Rising temperatures also increase the <a href="https://theconversation.com/rocky-mountain-forests-burning-more-now-than-any-time-in-the-past-2-000-years-162383">risk of large forest fires</a> like those that <a href="https://www.yellowstonepark.com/park/history/1988-fires-yellowstone/">scarred Yellowstone in 1988</a> and <a href="https://theconversation.com/the-year-the-west-was-burning-how-the-2020-wildfire-season-got-so-extreme-148804">broke records across Colorado in 2020</a>. And the effects on the national parks could harm the region’s <a href="https://www.nps.gov/grte/learn/news/-792-million-in-local-economic-benefits.htm">nearly US$800 billion</a> in annual tourism activity across the three states. </p>
<p>A group of scientists led by <a href="https://www.researchgate.net/profile/Cathy-Whitlock">Cathy Whitlock</a> from Montana State University, <a href="https://www.researchgate.net/profile/Steven-Hostetler">Steve Hostetler</a> of the U.S. Geological Survey <a href="https://scholar.google.com/citations?user=S5HWncYAAAAJ&hl=en">and myself</a> at the University of Wyoming partnered with local organizations, including the Greater Yellowstone Coalition, to <a href="https://gyclimate.org/">launch the climate assessment</a>.</p>
<p>We wanted to create a common baseline for discussion among the region’s many voices, from the Indigenous nations who have lived in these landscapes for over 10,000 years to the federal agencies mandated to care for the region’s public lands. What information would ranchers and outfitters, skiers and energy producers need to know to begin planning for the future?</p>
<figure class="align-center ">
<img alt="A group of elk in a grassland area." src="https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407748/original/file-20210622-13-150pr5h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Elk in the Greater Yellowstone Area could be affected by changes in the availability and quality of plants they eat along their migration routes. Changes to the elk population would in turn have an impact on grizzlies, wolves, and other parts of the food chain.</span>
<span class="attribution"><span class="source">Bryan Shuman/University of Wyoming</span></span>
</figcaption>
</figure>
<h2>Shifting from snow to rain</h2>
<p>Standing at the University of Wyoming-National Park Service Research Station and looking up at the snow on the Grand Teton, over 13,000 feet above sea level, I cannot help but think that the transition away from snow is the most striking outcome that the assessment anticipates – and the most dire.</p>
<p>Today the average winter snowline – the level where almost all winter precipitation falls as snow – is at an elevation of about 6,000 feet. By the end of the century, warming is forecast to raise it to at least 10,000 feet, the top of <a href="https://www.skimag.com/ski-resort-life/jackson-hole-2/">Jackson Hole’s famous ski areas</a>.</p>
<p>The climate assessment uses projections of future climates based on <a href="https://sos.noaa.gov/datasets/climate-model-temperature-change-rcp-45-2006-2100/">a scenario</a> that assumes countries substantially reduce their greenhouse gas emissions. When we looked at scenarios in which global emissions continue at a high rate instead, the differences by the end of century compared with today became stark. Not even the highest peaks would regularly receive snow.</p>
<p>In interviews with people across the region, nearly everyone agreed that the challenge ahead is directly connected to water. As a member of one of the regional tribes noted, “Water is a big concern for everybody.”</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=215&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=215&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=215&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=271&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=271&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407739/original/file-20210622-25-ogvj1l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=271&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">As temperature has risen over the past seven decades, snowfall has declined, and peak streamflow shifted earlier in the year across the Greater Yellowstone Area.</span>
<span class="attribution"><a class="source" href="https://gyclimate.org/">2021 Greater Yellowstone Climate Assessment</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Precipitation may increase slightly as the region warms, but less of it will fall as snow. More of it will fall in spring and autumn, while summers will become drier than they have been, our assessment found.</p>
<p>The timing of the spring runoff, when winter snow melts and feeds into streams and rivers, has already shifted ahead by about eight days since 1950. The shift means a longer, drier late summer when drought can turn the landscape brown – or black as the wildfire season becomes longer and hotter.</p>
<p>The outcomes will affect wildlife migrations dependent on the “<a href="https://doi.org/10.1111/gcb.15169">green wave”</a> of new leaves that rises up the mountain slopes each spring. Low streamflow and warm water in late summer will threaten the survival of coldwater fisheries, like the Yellowstone cutthroat trout, and Yellowstone’s unique species like the <a href="https://www.jhnewsandguide.com/jackson_hole_daily/local/teton-dwelling-stonefly-becomes-threatened/article_b55af516-e080-5b0d-9035-8d3fa3817156.html">western glacier stonefly</a>, which depends on the meltwater from mountain glaciers. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=308&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=308&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=308&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=387&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=387&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407752/original/file-20210622-27-j1doxm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=387&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Temperatures are projected to rise in the Greater Yellowstone Area in the coming decades. The chart shows two potential scenarios, based on different projections of what global warming might look like in the future – RCP 8.5, if greenhouse gas emissions continue at a high rate; and RCP 4.5, if countries take substantial steps to slow climate change. The temperatures are compared with the 1900-2005 average.</span>
<span class="attribution"><a class="source" href="https://gyclimate.org/">2021 Greater Yellowstone Climate Assessment</a></span>
</figcaption>
</figure>
<h2>Preparing for a warming future</h2>
<p>These outcomes will vary somewhat from location to location, but no area will be untouched.</p>
<p>We hope the climate assessment will help communities anticipate the complex impacts ahead and start planning for the future. </p>
<p>As the report indicates, that future will depend on choices made now and in the coming years. Federal and state policy choices will determine whether the world will see optimistic scenarios or scenarios where adaption becomes more difficult. The Yellowstone region, one of the coldest parts of the U.S., will face changes, but actions now can help avoid the worst. High-elevation mountain towns <a href="https://www.jacksonholechamber.com/trip-planner/weather/">like Jackson, Wyoming</a>, which today rarely experience 90 F, may face a couple of weeks of such heat by the end of the century – or they may face two months of it, depending in large part on those decisions.</p>
<p>The assessment underscores the need for discussion. What choices do we want to make?</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/163223/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bryan Shuman receives funding from the National Science Foundation. The Greater Yellowstone Climate Assessment was funded by the Greater Yellowstone Coordinating Committee, Montana State University, the University of Wyoming, the U.S. Geological Survey, and the Greater Yellowstone Coalition. </span></em></p>The area’s iconic national parks are home to grizzlies, elk and mountain snowfall that feeds some of the country’s most important rivers. A new report show the changes underway as temperatures rise.Bryan Shuman, Professor of Paleoclimatology and Paleoecology, University of WyomingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1588642021-06-01T12:51:24Z2021-06-01T12:51:24ZOvercrowded US national parks need a reservation system<figure><img src="https://images.theconversation.com/files/403188/original/file-20210527-20-t6x0qh.jpg?ixlib=rb-1.1.0&rect=48%2C24%2C5385%2C3538&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Traffic at the south entrance to Yellowstone National Park on Aug. 20, 2015.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/FYcyXr">Neal Herbert, NPS/Flickr</a></span></figcaption></figure><p>If you’re headed out into the wild this summer, you may need to jump online and book a reservation before you go. For the second consecutive year, reservations are required to visit <a href="https://www.nps.gov/yose/learn/historyculture/index.htm">Yosemite</a>, <a href="https://www.nps.gov/romo/index.htm">Rocky Mountain</a> and <a href="https://www.nps.gov/glac/index.htm">Glacier</a> national parks. Other popular sites, including Maine’s <a href="https://www.nps.gov/acad/index.htm">Acadia National Park</a>, encourage visitors to buy entrance passes in advance. </p>
<p>Limiting visitors has two purposes: reducing COVID-19 risks and allowing some parks to recover from recent wildfires. Rocky Mountain will allow 75% to 85% of capacity. Yosemite will again restrict the number of vehicles allowed in; last year, it hosted half of its <a href="https://theknow.denverpost.com/2020/02/27/national-park-attendance-2019-rocky-mountain-national-park/234480/">average 4 million annual visitors</a>. </p>
<p>Nationwide, some U.S. parks were <a href="https://www.nps.gov/orgs/1207/02-25-21-national-parks-hosted-237-million-visitors-in-2020.htm">emptier than normal</a> during the pandemic, while Yellowstone and others were near capacity. But the pandemic likely was a temporary pause in a rising tide of visitors. </p>
<p>America’s national parks face a popularity crisis. From 2010 to 2019, the number of national park visitors <a href="https://irma.nps.gov/stats">spiked</a> from 281 million to 327 million, largely driven by social media, advertising and increasing <a href="https://www.ustravel.org/press/study-more-overseas-visitors-choosing-us-national-parks">foreign tourism</a>. </p>
<p>This exponential growth is generating pollution and putting wildlife at risk to a degree that threatens the future of the park system. And with Americans eager to get back out into the world, the summer of 2021 promises to be one of the busiest domestic travel seasons in recent history. Reservations and other policies to manage visitor numbers could become features at many of the most popular parks.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/O-wAQkYJ4Fk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Crowding in the national parks has been rising for years and has spiked since 2010.</span></figcaption>
</figure>
<h2>Protecting treasured lands</h2>
<p>In <a href="https://scholar.google.com/citations?user=T-M08SYAAAAJ&hl=en">my work</a>, I’ve explored the history of national parks and the factors that drive people to seek experiences outdoors. I’ve also studied the impacts of national park visitation and ways to keep the public from loving national parks to death. </p>
<p>Much of that research has focused on California’s Yosemite National Park, which contains nearly 1,200 square miles of wilderness, including iconic granite rock formations, deep valleys, waterfalls and ancient giant sequoias. </p>
<p>Its creation dates to the Civil War. In 1864, with this landscape threatened by an influx of settlers and visitors, Abraham Lincoln signed <a href="https://www.nps.gov/parkhistory/online_books/anps/anps_1a.htm">the Yosemite Act</a>, which ceded the region to California for “public use, resort, and recreation.” This step set a precedent that parks were for everyone’s benefit and enjoyment. Congress <a href="https://www.nps.gov/articles/john-muir.htm">made Yosemite a national park</a> in 1890. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Roosevelt on horseback looking elated." src="https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403201/original/file-20210527-17-16o0xng.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">President Theodore Roosevelt arriving at Yellowstone National Park in 1903.</span>
<span class="attribution"><a class="source" href="https://www.doi.gov/blog/conservation-legacy-theodore-roosevelt">Library of Congress</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Influenced by naturalist John Muir, <a href="https://www.nps.gov/thrb/learn/historyculture/trandthenpsystem.htm">President Theodore Roosevelt</a> established five new parks in the early 1900s, along with 16 national monuments that included the Grand Canyon. Roosevelt wanted to protect these natural treasures from hunting, mining, logging and other exploitation. </p>
<p>To coordinate management, Congress established the <a href="https://www.nps.gov/index.htm">National Park Service</a> and the <a href="https://www.nps.gov/aboutus/national-park-system.htm">National Park System</a> in 1916. The <a href="https://www.doi.gov/ocl/nps-organic-act">National Park Service Organic Act</a> directs the agency to protect the parks’ wildlife and natural and cultural heritage “in such manner and by such means as will leave them unimpaired for the enjoyment of future generations” – a mission that is becoming increasingly difficult today.</p>
<h2>Loving the parks to death</h2>
<p>Americans fell in love with their parks – and several waves of overpopularity nearly destroyed the very experiences that drew people there. </p>
<p>The advent of automobile tourism in the 1920s opened national parks to hundreds of thousands of new visitors, who overwhelmed limited, aging roads, trails, restrooms, water treatment systems and visitor facilities. Ironically, relief came during the Great Depression. The New Deal funded massive construction projects in the parks, including campground comfort stations, museums and other structures. Hundreds of miles of roads and trails opened wild backcountry. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Crowds at a ceremony with mountains in the background." src="https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=531&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=531&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403197/original/file-20210527-19-4t59v6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=531&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dedication of Going-to-the-Sun Road in Glacier National Park, Montana, on July 15, 1933.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/HxPpPW">George A. Grant, NPS/Flickr</a></span>
</figcaption>
</figure>
<p>Between 1929 and 1941, the number of annual park visitors grew from 3 million to 20 million. This increasing torrent slowed only when the U.S. entered World War II.</p>
<p>In the postwar boom, people returned en masse. The National Park Service launched <a href="https://www.nps.gov/subjects/southfloridacollections/introduction-mission-66-exhibit.htm">“Mission 66,”</a> another flurry of construction that again expanded capacity. </p>
<p>Conservationists and others condemned the development, alarmed by its <a href="https://www.nps.gov/parkhistory/online_books/anps/anps_6.htm">environmental impacts and the threat of overcrowding</a>. By the mid-1960s, total yearly park visitation exceeded 100 million.</p>
<h2>Riding the tourism wave</h2>
<p>Today the national park system has grown to comprise 63 national parks, with ever more visitors, plus <a href="https://theknow.denverpost.com/2020/02/27/national-park-attendance-2019-rocky-mountain-national-park/234480/">360 sites with other designations</a>, such as national seashores, monuments and battlefields. Some of these other sites, such as <a href="https://www.nps.gov/caco/index.htm">Cape Cod National Seashore</a> in Massachusetts and <a href="https://www.nps.gov/gett/index.htm">Gettysburg National Military Park</a> in Pennsylvania, also attract millions of visitors yearly. </p>
<p>In 2019, <a href="https://www.nps.gov/aboutus/visitation-numbers.htm">a record-setting 327 million people</a> visited the national parks, with the heaviest impacts on parks located near cities, like Rocky Mountain National Park outside Denver. This crowding spotlighted problems that park officials had been raising concerns about for years: The parks are <a href="https://www.nps.gov/parkhistory/online_books/anps/anps_7.htm">underfunded, overrun, overbuilt and threatened by air and water pollution</a> <a href="https://www.nps.gov/parkhistory/online_books/anps/anps_8.htm">in violation</a> of the laws and executive orders that protected them. </p>
<p>Park horror stories have grown common in recent years. They include miles-long <a href="https://www.roughguides.com/special-features/the-truth-about-tourism-in-yellowstone-national-park/">traffic jams</a> in Yellowstone, <a href="https://www.nps.gov/yose/planyourvisit/traffic.htm">three-hour waits</a> to enter Yosemite, trails <a href="https://time.com/5869788/national-parks-covid-19/">littered with trash</a> and confrontations between <a href="https://abcnews.go.com/US/bison-attacks-stay-safe-wildlife-visiting-national-parks/story?id=64653338">tourists</a> and <a href="https://www.powelltribune.com/stories/drivers-killed-76-large-animals-on-yellowstone-roads-last-year,21844">wildlife</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1153992380728483840"}"></div></p>
<p>In 2020, Congress passed the <a href="https://www.congress.gov/bill/116th-congress/house-bill/1957">Great American Outdoors Act</a>, which will provide up to US$1.9 billion a year for five years to address the park system’s <a href="https://www.nps.gov/subjects/infrastructure/deferred-maintenance.htm">nearly $12 billion maintenance backlog</a>. This long list of postponed projects reflects <a href="https://theconversation.com/americans-think-national-parks-are-worth-us-92-billion-but-we-dont-fund-them-accordingly-57617">Congress’ reluctance to adequately fund the national park system</a> over many years.</p>
<p>But as the New Deal and Mission 66 demonstrated, increased infrastructure spending often boosts visitation. The Great American Outdoors Act doesn’t cover conservation efforts or significant personnel needs, which will require increased federal funding. Many repairs are needed throughout the parks, but the system’s future sustainability relies more on staffing than infrastructure. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cruise ship, crowds lining the railings." src="https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/402679/original/file-20210525-15-1suzxx6.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 cruise ship approaches Margerie Glacier in Alaska’s Glacier Bay National Park in 2018.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/26YUTwo">NPS/Flickr</a></span>
</figcaption>
</figure>
<p>And neither more money nor additional park rangers will solve the overcrowding crisis. I believe the most popular national parks need a reservation system to save these protected lands from further damage. </p>
<p>This won’t be a popular solution, since it contradicts the founding premise that national parks were built for public benefit and enjoyment. Critics have already created a <a href="https://www.change.org/p/joe-neguse-public-lands-and-for-the-people-not-the-privileged?utm_source=share_petition&utm_medium=custom_url&recruited_by_id=3f0cd440-80ff-11e6-aedf-6f28f8ac7aeb">petition</a> opposing Rocky Mountain National Park’s timed entry permits as unnecessary, unfair, undemocratic and discriminatory. </p>
<p>But the parks’ unrelenting popularity is making it impossible to preserve them “unimpaired.” In my view, crowd control has become essential in the most popular parks. </p>
<p>While there is only one Yosemite Valley, the national park system offers many less crowded destinations. Sites such as <a href="https://www.nps.gov/hove/index.htm">Hovenweep National Monument</a> in Colorado and Utah and the <a href="https://www.nps.gov/brvb/index.htm">Brown v. Board of Education National Historic Site</a> in Kansas deserve attention for their natural beauty and the depth they add to <a href="https://www.lonelyplanet.com/articles/underrated-us-national-parks">Americans’ shared heritage</a>.</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/158864/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Childers 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>It’s hard to preserve national parks “unimpaired,” as US law directs, when they’re overrun with tourists who stray off paths, strew trash and harass wildlife. A parks scholar calls for crowd control.Michael Childers, Assistant Professor of History, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1014952018-08-28T10:38:44Z2018-08-28T10:38:44ZHere’s how forests rebounded from Yellowstone’s epic 1988 fires – and why that could be harder in the future<figure><img src="https://images.theconversation.com/files/233131/original/file-20180822-149475-cth24y.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The 2016 Maple fire (photographed in July 2017) reburned young forests that had regenerated after the 1988 Yellowstone fires. More frequent high-severity fires are expected in the future as climate warms, which may change patterns of forest recovery.</span> <span class="attribution"><span class="source">Monica Turner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>This summer marks the 30th anniversary of the <a href="https://www.nps.gov/yell/learn/nature/1988fires.htm">1988 Yellowstone fires</a> – massive blazes that affected about 1.2 million acres in and around Yellowstone National Park. Their size and severity surprised scientists, managers and the public and received heavy media coverage. Many news reports proclaimed that Yellowstone was destroyed, but nothing was further from the truth. </p>
<p>I was there during the fires and returned that fall to view the aftermath. Burned forests extended for miles, with blackened tree trunks creating a stark and seemingly desolate landscape. But peering down from a helicopter, we were surprised to see that the fires had actually produced a mosaic of burned and unburned patches of forest. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233517/original/file-20180824-149490-1w0c1yp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Landscape pattern of burned and unburned trees after the Yellowstone fires, October 1988.</span>
<span class="attribution"><span class="source">Monica Turner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>I have studied the recovery of Yellowstone’s forests since 1989, watching landscapes of charred trees transition into lush young forests. Fires play an important ecological role in many ecosystems, and Yellowstone’s native plants and animals are <a href="https://doi.org/10.1007/s10021-011-9470-6">well-adapted to historical cycles of disturbance and recovery</a>. Today the burned landscape is dominated by <a href="https://doi.org/10.1890/15-1585.1">thriving young lodgepole pine trees</a>. </p>
<p>We learned much about <a href="https://press.uchicago.edu/ucp/books/book/chicago/S/bo25126049.html">how ecosystems respond to such fires</a> because they burned mostly in national parks and wilderness areas. Post-fire management was minimal, and nature took its course through most of the burned area. </p>
<p>Because <a href="https://doi.org/10.1890/10-0097.1">Yellowstone’s forests were remarkably resilient</a>, the 1988 fires were not an ecological catastrophe. Today, however, climate and fire trends may be pushing forests beyond their limits. The rules of the game are changing fast.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233518/original/file-20180824-149466-1g3ongx.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">Post-1988 young lodgepole pine forests, photographed in 2014.</span>
<span class="attribution"><span class="source">Monica Turner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Heat, drought and wind</h2>
<p><a href="https://doi.org/10.1139/x92-005">Extreme weather conditions</a> drove the 1988 fires, as they have fostered many recent fires across the West. Summers in Yellowstone are usually too cool and moist for such large fires, but the summer of 1988 was and remains the driest on record there. </p>
<p>Amounts of fuel (dead logs and pine needles on the ground and live trees) were not unusual, and there is no evidence that suppression of prior fires had much, if any, influence on the 1988 fires. Hot temperatures, severe drought and high winds set the stage. </p>
<p>Gusts over 60 miles per hour prevented me from flying over the fires in early July, well before the blazes made their biggest runs. Roads, rivers and even wide canyons spanning the Yellowstone and Lewis rivers did not stop flames from spreading on windy days. Strong winds carried burning branches ahead of the main fire front, advancing fire spread. The fires also continued to burn at night. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233522/original/file-20180824-149487-ij6yat.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Crown fire at Grant Village in Yellowstone National Park, July 23, 1988.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Ground_fire_at_Grant_Village_2.jpg">National Park Service/Jeff Henry</a></span>
</figcaption>
</figure>
<h2>How burned forests recover</h2>
<p>Severe fires have burned in Yellowstone at <a href="http://apcg.uoregon.edu/envchange/figures/millspaugh-etal-geology-2000-figs/millspaugh.pdf">100- to 300-year intervals</a> for the past 10,000 years. “Crown fires” burn through the forest canopy, killing the trees while triggering a flush of new growth. Such fires are <a href="https://doi.org/10.2307/1311000">business as usual in Yellowstone</a> and <a href="https://doi.org/10.1007/BF00135079">many other forests at high elevations and far north latitudes</a>. </p>
<p>Lodgepole pines have thin bark and are readily killed, but often bear fire-adapted cones that allow them to regenerate right after fires. When heated, the cones release vast quantities of seeds that produce a new generation of trees. Fires also create ideal growing conditions, with plenty of mineral soil and sunlight.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233523/original/file-20180824-149493-97r2kp.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">Wildflowers flourish three years after the 2008 Gunbarrel fire east of Yellowstone.</span>
<span class="attribution"><span class="source">Monica Turner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In Yellowstone, wildflowers and grasses sprouted from surviving roots because soils did not burn deeply and <a href="https://doi.org/10.1073/pnas.0700180104">retained key nutrients</a> needed for plant growth. <a href="https://doi.org/10.1002/ecm.1220">Native species steadily filled in</a> the bare spots. Aspens – long a species of concern in the northern Rockies – established from seed throughout the burned pine forests, many miles from the nearest mature aspen trees. Many are <a href="https://doi.org/10.1016/j.foreco.2015.12.012">doing well at higher elevations</a> than their pre-fire distribution. </p>
<p>Yellowstone’s ecosystems recovered rapidly on their own. I suspect that many visitors no longer “see” evidence of the 1988 fires as they admire scenery and wildlife amidst a sea of green. Similar patterns of natural recovery following 20th-century fires have also been observed in Rocky Mountain, Glacier and Grand Teton National Parks, which also have evolved with fire for millennia. Historically, high-severity fires kill trees but do not destroy the forest.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=504&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=504&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=504&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=634&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=634&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233524/original/file-20180824-149481-160v3hr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=634&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Huckleberry Mountain in Glacier National Park after a fire on July 30, 1935 (top) and July 9, 2009 (bottom).</span>
<span class="attribution"><a class="source" href="https://www.nps.gov/fire/wildland-fire/learning-center/panoramic-lookout-photographs/photo-gallery/change-over-time.cfm">National Park Service</a></span>
</figcaption>
</figure>
<h2>Warming climate, more fire</h2>
<p>The 1988 fires <a href="http://dx.doi.org/10.1126/science.1130370">ushered in a new era of major wildfires</a> that are burning more western forests each year. Summers and winters are getting warmer, and the hot, dry weather associated with large fires is <a href="http://dx.doi.org/10.1098/rstb.2015.0178">no longer so rare</a>. Snow melts earlier each year, fuels dry out sooner, temperature records are broken and fire season gets longer. Recent fires have burned in many national parks and monuments, including <a href="https://www.nps.gov/band/index.htm">Bandelier</a>, <a href="https://www.nps.gov/romo/index.htm">Rocky Mountain</a>, <a href="https://www.nps.gov/glac/index.htm">Glacier</a> and <a href="https://www.nps.gov/yose/index.htm">Yosemite</a>.</p>
<p>A warmer, drier climate means that drought is getting worse in places that are already hot and dry. In the western United States, human-caused climate change has <a href="https://doi.org/10.1073/pnas.1607171113">dried fuels and nearly doubled the area burned by forest fires</a> from 1984 to 2015. </p>
<p>And while lightning ignites most fires in the northern Rockies, <a href="https://doi.org/10.1073/pnas.1617394114">human ignitions are lengthening fire seasons</a> in populated areas. Even in the moist mixed forests of the southern Appalachians, severe drought allowed a human-caused fire that started in Great Smoky Mountains National Park to rage into <a href="https://en.wikipedia.org/wiki/2016_Great_Smoky_Mountains_wildfires">Gatlinburg, Tennessee</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1015340245259173888"}"></div></p>
<h2>What lies ahead?</h2>
<p>Even forests that are well-adapted to large, severe fires are at risk in a warming world. By the late 21st century, hot, dry weather like the summer of 1988 could be the rule rather than the exception in Yellowstone. </p>
<p>Large fires are expected to <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1110199108">occur more often</a>, and are <a href="http://dx.doi.org/10.1002/ecy.1439">already starting to reburn forests</a> long before they have had enough time to recover. In Yellowstone and Grand Teton National Parks, <a href="https://www.youtube.com/watch?reload=9&v=GbO8VvcSldY">fires in 2016 burned young forests</a> that regenerated from fires in 1988 and 2000. Our studies of these recent fires have documented greater burn severity and fewer post-fire tree seedlings. Survival of these young trees is not guaranteed, as they are starting out in a much warmer world. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/dD8VLS5F2Xo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Big and severe fires are now burning more frequently and could threaten the resilience of Western forests.</span></figcaption>
</figure>
<p>National parks anchor many of the country’s last intact landscapes, and are among our best living laboratories for understanding environmental change. Research on the 1988 fires now provides a reference for assessing effects of more recent fires. Yellowstone will still maintain its beauty, native species and power to inspire us. However, only time will tell whether Yellowstone’s forests can maintain their <a href="https://doi.org/10.1002/fee.1311">ability to recover</a> from fire in the decades ahead.</p><img src="https://counter.theconversation.com/content/101495/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monica Turner receives funding from the National Science Foundation, Joint Fire Science Program, US National Park Service Reserve Funds, Wisconsin Alumni Research Foundation (UW2020 Initiative), and the University of Wisconsin Vilas Trust. </span></em></p>Huge fires roared through Yellowstone National Park in the summer of 1988, scorching one-third of the park. Since then the park has been a valuable lab for studying how forests recover from fires.Monica G. Turner, Professor of Ecology, University of Wisconsin-MadisonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/721852017-02-08T18:57:40Z2017-02-08T18:57:40ZA wolf in dogs’ clothing? Why dingoes may not be Australian wildlife’s saviours<figure><img src="https://images.theconversation.com/files/155770/original/image-20170206-27210-183a5hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dingoes are often promoted as a solution to Australia's species conservation problems.</span> <span class="attribution"><span class="source">Dingo image from www.shutterstock.com</span></span></figcaption></figure><p>Dingoes have often been <a href="https://theconversation.com/what-american-wolves-can-teach-us-about-australian-dingoes-27815">hailed as a solution</a> to Australia’s threatened species crisis, particularly the <a href="https://theconversation.com/australia-should-enlist-dingoes-to-control-invasive-species-24807">extreme extinction rate</a> of the country’s small mammals. </p>
<p>But are dingoes really the heroes-in-waiting of Australian conservation? The truth is that no one knows, although our <a href="http://www.sciencedirect.com/science/article/pii/S2352249616300143">recent research</a> casts a shadow over some foundations of this idea. </p>
<p>The notion of dingoes as protectors of Australian ecosystems was inspired largely by the <a href="http://www.yellowstonepark.com/wolf-reintroduction-changes-ecosystem/">apparently successful reintroduction of wolves into Yellowstone National Park</a> in the United States. But Australia’s environments are very different. </p>
<h2>Cascading species</h2>
<p>To understand the recent excitement about wolves, we need to consider an ecological phenomenon known as “<a href="https://www.jstor.org/stable/pdf/3450972.pdf">trophic cascades</a>”. The term “trophic” essentially refers to food, and thus trophic interactions involve the transfer of energy between organisms when one eats another.</p>
<p>Within ecosystems, there are different trophic levels. Plants are typically near the base; herbivores (animals that eat plants) are nearer the middle; and predators (animals that eat other animals) are at the top. </p>
<p>The theory of trophic cascades describes what happens when something disrupts populations of top-order predators, such as lions in Africa, tigers in Asia, or Yellowstone’s wolves. </p>
<p>The wolves’ decline allowed herbivores, such as elk, to increase. In turn, the growing elk population ate too much of the shrubby vegetation alongside rivers, which, over time, changed from being mostly willow thickets to grassland. Then another herbivore – beavers – that relies on willows went locally extinct. This in turn affected the ecology of the local streams. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155772/original/image-20170206-27210-hl84ot.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">Wolves play a key role in Yellowstone’s ecosystems.</span>
<span class="attribution"><span class="source">Wolf image from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>Without beavers to engineer dams, local waterways changed from a series of connected pools to eroded gutters, with huge flow-on effects for smaller aquatic animals and plants. </p>
<p>Now, the reintroduction of wolves appears to have reduced the impact of elk on vegetation, some riparian areas have regenerated, some birds have returned and there are signs of beavers coming back. That said, <a href="http://rspb.royalsocietypublishing.org/content/280/1756/20122977">wolf reintroduction</a> has not yet fully reversed the trophic cascade.</p>
<h2>Comparing apples with quandongs</h2>
<p><a href="https://theconversation.com/lets-move-the-worlds-longest-fence-to-settle-the-dingo-debate-37155">Sturt National Park</a>, in the New South Wales outback, has been nominated as an experimental site for reintroducing dingoes. Recently, we compared the environment of Sturt with Yellowstone to consider how such a reintroduction might play out. </p>
<p>These regions are clearly very different. Both are arid, but that is where the similarity ends. Yellowstone has a stable climate and nutrient-rich soils, sits at high altitude and features diverse landscapes. Precipitation in Yellowstone hasn’t dropped below 200mm per year in more than a century.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155768/original/image-20170206-27204-m3v9ey.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">Herds of bison in Yellowstone National Park.</span>
<span class="attribution"><span class="source">Helen Morgan</span></span>
</figcaption>
</figure>
<p>Yellowstone’s precipitation falls largely as heavy winter snow. Each spring the snowmelt flows in huge volumes into rivers, streams and wetlands across the landscape. This underpins a predictable supply of resources which, in turn, triggers herbivores to migrate and reproduce every year.</p>
<p>These predictable conditions support a wide range of carnivores and herbivores, including some of North America’s last-remaining “megafauna”, such as bison, which can tip the scales at over a tonne. Yellowstone also has many large predators – wolves, grizzly bears, black bears, mountain lion, lynx and coyotes all coexist there – along with a range of smaller predators too.</p>
<p>Predators in Yellowstone can be sure that prey will be available at particular times. The environment promotes stable, strong trophic links, allowing individual animals to reach large sizes. This strong relationship between trophic levels means that when the system is perturbed – for instance, when wolves are removed – trophic cascades can occur. </p>
<p>Unlike Yellowstone, arid Australia is dry, flat, nutrient-poor and characterised by one of the most extreme and unpredictable climates on Earth. The yearly rainfall at Sturt reaches 200mm just 50% of the time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155769/original/image-20170206-27202-20ywfn.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Australia’s Sturt Desert has a highly unpredictable climate.</span>
<span class="attribution"><span class="source">Helen Morgan</span></span>
</figcaption>
</figure>
<p>Australia’s arid ecosystems have evolved largely in isolation for 45 million years. In response to drought, fire and poor soils, arid Australia has evolved highly specialised ecosystems, made up of species that can survive well-documented <a href="http://link.springer.com/article/10.1007/s10531-005-0601-2">“boom and bust” cycles</a>. </p>
<p>Unlike the regular rhythm of Yellowstone life, sporadic pulses of water and fire affect and override the trophic interactions of species, between plants and herbivores, and predators and their prey. Our native herbivores travel in response to patchy and unpredictable food sources in boom times. But however good the boom, the bust is certain to follow.</p>
<p>Unpredictable but inevitable drought weakens trophic links between predators, herbivores and plants. Individuals die due to lack of water, populations are reduced and can only recover when rain comes again. </p>
<p>Our arid wildlife is very different from Yellowstone’s too. Our megafauna are long gone. So too are our medium-sized predators, such as thylacines. </p>
<p>Today, arid Australia’s remaining native wildlife is characterised by birds, reptiles and small mammals, along with macropods that are generally much smaller than the herbivores in Yellowstone. </p>
<p>Our predators are small and mostly introduced species, including dingoes, foxes and cats. None is equivalent to wolves, mountain lions or bears, which can reach more than three times the weight of the largest dingo. Wolves are wolves, and dingoes are dogs.</p>
<h2>Wolves in dingo clothes?</h2>
<p>What does all this mean for Australia? Yellowstone’s stable climate means that there are strong and reliable links between predators, prey and plants. By comparison, arid Australia’s climate is dramatically unstable. </p>
<p>This raises the question of whether we can reasonably expect to see the same sorts of relationships between species, and whether dingoes are likely to help restore Australia’s ecosystems. </p>
<p>We should conduct experiments to understand the roles of dingoes and the impacts of managing them. How we manage predators, including dingoes, should be informed by robust knowledge of local ecosystems, including predators’ roles within them.</p>
<p>What we shouldn’t do is expect that dingoes will necessarily help Australia’s wildlife, based on what wolves have done in snowy America. The underlying ecosystems are very different. </p>
<p>Many people are inspired by the apparently successful example of wolves returning to Yellowstone, but in Australia we should tread carefully. </p>
<p>Rather than trying to prove that dingoes in Australia are just as beneficial as wolves in Yellowstone, we should seek to understand the roles that dingoes really play here, and work from there.</p><img src="https://counter.theconversation.com/content/72185/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Morgan receives funding from the Keith and Dorothy Mackay Travelling Scholarship, University of New England, the Holsworth Wildlife Endowment Trust and Invasive Animals CRC</span></em></p><p class="fine-print"><em><span>Guy Ballard receives funding from the Invasive Animals Cooperative Research Centre, NSW Local Land Services and the NSW National Parks & Wildlife Service. </span></em></p><p class="fine-print"><em><span>John Thomas Hunter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The notion of using dingoes to protect Australia’s wildlife is based on wolves in the US, but research cast doubts on the link.Helen Morgan, Phd candidate, Ecology, University of New EnglandGuy Ballard, Adjunct Senior Lecturer, University of New EnglandJohn Thomas Hunter, Adjunct Associate Professor in Landscape Ecology, University of New EnglandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/591482016-06-01T01:00:21Z2016-06-01T01:00:21ZUnlocking the secrets of bacterial biofilms – to use against them<figure><img src="https://images.theconversation.com/files/124356/original/image-20160527-894-iuv5a8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's bacterial biofilms that give the Grand Prismatic Spring its colorful hues.</span> <span class="attribution"><span class="source">Karin Sauer</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Standing on a walkway at Yellowstone National Park, I admired the hues of orange, blue and yellow in the sand of the Grand Prismatic Spring. A small sign nearby read “bacterial mats.” Visitors to Yellowstone may have noticed similar signs all over the park, but they’re often overlooked on the way to waterfalls, geysers, hot springs and more.</p>
<p>But these colorful structures at my feet were the reason I had come. Well, I needed a vacation – and what better place then Yellowstone? – but professional curiosity had a lot to do with the destination. I’m a microbiologist, and I had come to see the bacterial mats.</p>
<p>More commonly known as biofilms, these communities of tightly packed bacteria grow in close association with surfaces such as sand and soil. The term “biofilms” suggests a thin, two-dimensional substance, but these communities feature microscopic-scale tower-like structures crisscrossed with water channels, all of which is encased in a protective, self-produced slimy layer. The bacteria within communicate and demonstrate cooperative behavior reminiscent of primitive organs.</p>
<p>As visually stunning as I find these biofilms in nature, these bacterial communities can be detrimental to human health. Scientists like me are investigating how these bacterial biofilms form and behave so we can figure out new ways to manage and control them.</p>
<h2>Biofilms are all around us</h2>
<p>While made up of bacteria that are invisible to the naked eye, biofilms themselves can be much bigger, ranging from less than an inch to several hundred feet in size. Yellowstone is home to the most extensive and most colorful biofilms I’ve ever seen, but these bacterial communities are not unique to the park. Biofilms are found anywhere in nature, visible as <a href="http://genomealberta.ca/blogs/curiosity-about-stromatolites-and-biofilm.aspx">stromatolites</a>, pond scum and the slimy, slippery layer coating rocks and pebbles in streams.</p>
<p>And biofilms are not limited to the environment, either, since bacteria will stick to almost any surface in aqueous conditions and encase themselves with a slime matrix. Indeed, biofilms pose <a href="http://dx.doi.org/10.1080/87559129209540953">numerous problems to human-made materials</a> such as ship hulls, cooling towers, sewage treatment plants, oil refineries, food processing and beverage plants, and household plumbing. You’ve likely seen them yourself while cleaning or doing repairs in your kitchen or bathroom, as a thick and slimy buildup in your drains and pipes. Biofilms can be a real nuisance, <a href="http://www.slideshare.net/mfornalik/intro-to-biofilms-3522031">causing biofouling and corrosion</a>.</p>
<p>The <a href="http://dx.doi.org/10.1126/science.284.5418.1318">ubiquity of biofilms</a> in our surroundings is supported by findings that the majority of bacteria, up to 90 percent, prefer <a href="http://www.ncbi.nlm.nih.gov/pubmed/340020">living in surface-associated biofilm communities</a> rather than as free-floating, individual bacteria (what we call planktonic bacteria).</p>
<p>So why do bacteria <a href="http://dx.doi.org/10.1128/JB.00003-12">tend to form communities</a>? For one thing, there’s strength in numbers. By banding together within their slimy protection, biofilm bacteria can remain in favorable locations or hosts, better withstand nutrient deprivation, stress, dessication and predation. At the same time, they benefit from increased cooperation and exchange of genetic material.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124520/original/image-20160530-7692-10riis.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">Scanning electron micrograph of part of a central venous catheter, removed from a patient, that was colonized by a biofilm of rod-shaped bacteria associated with fibrinlike material on the catheter’s surface.</span>
<span class="attribution"><a class="source" href="http://phil.cdc.gov/">Janice Haney Carr</a></span>
</figcaption>
</figure>
<h2>Biofilms can harm human health</h2>
<p>Biofilms have been linked to contamination of <a href="http://dx.doi.org/10.1089/10445490260099700">contact lenses leading to corneal ulcers</a>. They’re associated with <a href="http://dx.doi.org/10.1177/0022034510368644">dental plaque that leads to caries and periodontitis</a>. <a href="http://dx.doi.org/10.1126/science.284.5418.1318">They can infect</a> <a href="http://dx.doi.org/10.1007/978-3-319-09782-4">surgical sites</a>, the urinary tract, chronic and burn wounds and the lungs of cystic fibrosis patients. And they love to <a href="http://dx.doi.org/10.1016/B978-0-323-22805-3.00005-0">colonize medical devices</a> such as catheters, prosthetic joints and heart valves.</p>
<p>According to the National Institutes of Health, more than 65 percent of <a href="http://dx.doi.org/10.1111/2049-632X.12151">chronic inflammatory and infectious diseases</a> are due to biofilms. According to research, biofilm-related infections claim as many lives as heart attack or cancer. And they are costly, with treatment of biofilm-related infections <a href="http://dx.doi.org/10.1002/bit.21838">ranging into the billions</a> annually worldwide.</p>
<p>Why are we not better equipped to treat such bacterial infections? Research by my laboratory and others has demonstrated that when bacteria attach to a surface and grow as biofilms, they undergo a change, as evidenced by the genes they express and the proteins they produce. One of the consequences of this change is that biofilm bacteria become less susceptible to biocides, disinfectants and antibiotics. </p>
<p>Scientists think there are several reasons for this decrease in susceptibility. First, the slimy layer encasing biofilms can make it hard for disinfectants or antimicrobials to even physically reach the bacteria. Also, bacteria living in biofilms experience high stress levels while growing rather slowly, which can render most antibiotics ineffective since they only work on actively growing cells. My favorite theory is that living in a biofilm changes bacteria and their behavior; something about their mix of active genes and proteins just makes them more resilient. Whatever the contributing factors, bacteria growing in a biofilm can be <a href="http://dx.doi.org/10.1128/JB.00765-12">up to 1,000-fold more resistant to antibiotics</a> than the same bacteria grown planktonically.</p>
<p>This profound tolerance to antimicrobial agents – a hallmark of biofilms – is at the root of many persistent infections and renders biofilms extremely difficult to control in medical settings. <a href="http://www.ncbi.nlm.nih.gov/books/NBK84450/">Conventional therapies have proven inadequate</a> in the treatment of many if not most chronic biofilm infections, mainly because they have been geared toward bacteria growing planktonically and not as biofilms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=264&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=264&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=264&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=332&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=332&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124591/original/image-20160531-1943-1tkghh6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=332&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 formation of surface-associated biofilm communities (A) can be prevented or significantly reduced (B) by interfering with key factors required for their development. Bacterial cells are stained green.</span>
<span class="attribution"><span class="source">Karin Sauer</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>New lines of attack against biofilms</h2>
<p>Research suggests a promising new avenue for biofilm control: the manipulation of the biofilm lifestyle. Yes, for bacteria, being in a biofilm is a lifestyle choice.</p>
<p>The biofilm way of life is initiated when a few planktonic bacteria adhere to a surface. Once attached, these bacteria will divide and grow into more complex, three-dimensional structures – the biofilm. If resources become exhausted or the biofilm become too overcrowded, bacteria can escape it, as a means of survival and dissemination.</p>
<p>It’s the two extremes of their lifestyle, the beginning and the end, attachment and escape, that have become major foci of research endeavors looking for ways to defeat biofilms.</p>
<p>When it comes to controlling attachment, much research has focused on the <a href="http://dx.doi.org/10.1111/j.1574-695X.2011.00858.x">development of new surface materials</a> aimed at preventing the formation of biofilms on medical devices in the first place. The idea is to render devices’ surfaces nonsticky, repelling or otherwise toxic for those first pioneering bacteria. If they can’t latch on and get a toehold, no biofilm can eventually form. Surface coatings containing colloidal silver, antibiotics or micro-brushes can render medical devices inhospitable.</p>
<p>Likewise, the hunt is on for new chemical compounds that prevent attachment or induce escape strategies. Researchers are <a href="http://dx.doi.org/10.1128/JB.01214-08">starting to have some success</a>.</p>
<p><a href="http://bingweb.binghamton.edu/%7Eksauer/">My own research</a>, along with that of colleagues at Binghamton University and around the world, has led me down another path. I’ve been trying to understand how bacteria actually make these amazing biofilm structures. What proteins, polymers and factors do they need to coordinate their lifestyle? What have we learned that would let us manipulate this biofilm lifestyle?</p>
<p>It’s unlikely there will be only one effective treatment strategy to defeat biofilms. For one thing, many varieties of bacteria form biofilms, and they all use somewhat different strategies to enable this lifestyle. For instance, while bacteria may coordinate the formation of biofilms via chemical signals, the molecules used by bacteria such as <em>E. coli</em> or <em>S. aureus</em> to do so differ quite dramatically. Likewise with the species-specific sets of proteins required to coordinate the formation of each kind of biofilm. So as we target individual characteristics, some of our tactics work better on one group than another. </p>
<p>But biofilm bacteria also share some common features that we can take advantage of, including their need for communication and coordination. Building a biofilm, escaping from the biofilm or even living in a biofilm requires some sort of coordination among the millions of bacteria that make it up. They can do so by communicating with each other, using a chemical language or proteins. Jamming the bacterial language (although there are many) or interfering with their key factors required for coordination has proven to be a successful strategy to block or modify biofilm formation, at least in laboratory settings and some clinical pilot studies.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124590/original/image-20160531-1943-iim40a.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Biofilms before (A) and after (B) exposure to ‘Escape from the biofilm!’ chemical signal. Note the biofilms in (B) are hollow, appearing like empty shells. Bacterial cells are stained in green.</span>
<span class="attribution"><span class="source">Karin Sauer</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Likewise, repurposing the bacterial language has shown promise. For instance, when we co-opt the bacterial language to signal “<a href="http://dx.doi.org/10.1128/JB.01214-08">escape from the biofilm!</a>” we can trick biofilm bacteria into giving up their protective lifestyle and converting to planktonic cells again. The added benefit is the planktonic cells are more susceptible to antibiotics.</p>
<p>Controlling biofilms in the future will likely require a combination of strategies, addressing both attachment and escape, with and without the use of antibiotics and communication blockers, and likely in a manner more or less tailored toward the different bacterial lifestyles.</p><img src="https://counter.theconversation.com/content/59148/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>My research is currently supported by grants from the National Institute of Health and F. Hoffmann-La Roche Ltd.
</span></em></p>The vast majority of the bacteria that surround us are not free-floating but prefer to band together in cooperative communities called biofilms. How do biofilms form and cooperate?Karin Sauer, Professor of Biological Sciences, Binghamton University, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/562162016-03-18T04:29:01Z2016-03-18T04:29:01ZHow bringing back predators can change the way prey behaves<figure><img src="https://images.theconversation.com/files/115304/original/image-20160316-30211-zbe23r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The reintroduction of lions and hyena has led animals in South Africa's Addo Elephant National Park to behave differently.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Large predator numbers are <a href="http://science.sciencemag.org/content/343/6167/1241484">declining</a> across the globe. These declines have considerable ecological knock-on <a href="http://science.sciencemag.org/content/333/6040/301">effects</a>, many of which are currently unknown. Novel conservation techniques are required to reverse predator declines.</p>
<p>One such conservation action is the <a href="http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1405176806.html">reintroduction of large predators</a> into areas from which they have been eradicated. These large predator reintroduction programmes have more than one benefit. They expand the range of many vulnerable and endangered species. They also restore ecological <a href="http://onlinelibrary.wiley.com/wol1/doi/10.1890/07-0308.1/abstract">predator-prey interactions</a>, as well as boosting local tourism <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1469-1795.2012.00595.x/abstract">opportunities</a>.</p>
<p>The most publicised and well known of these programmes was the <a href="http://www.nps.gov/yell/learn/nature/wolf-restoration.htm">reintroduction of wolves</a> into the Yellowstone National Park in the US. This resulted in an <a href="https://www.youtube.com/watch?v=ysa5OBhXz-Q">ecological cascade</a>, or knock-on effects. There were several of these but a key one was fearful elk moving away from rivers. This in turn led to the recovery of riverine vegetation, which in turn increased the abundance of <a href="http://www.sciencedirect.com/science/article/pii/S0006320711004046">songbirds</a>, <a href="http://www.yellowstonepark.com/wolf-reintroduction-changes-ecosystem/">beavers</a> and other species.</p>
<p>These observations have spurred scientists worldwide to focus their efforts on trying to unravel how ecosystems respond to predator reintroductions. This focus has increased the understanding of predator-prey interactions, but has also highlighted gaps in the understanding of the role of predators.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/115303/original/image-20160316-30219-1pqtbyd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The reintroduction of wolves in the Yellowstone National Park has had ecological knock-on effects.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>Will it work in Africa?</h2>
<p>Transferring the trophic cascade ideas developed in Yellowstone to African ecosystems is not a simple process. African ecosystems are extremely complex. They harbour a larger suite of predators preying on a larger <a href="https://www.sciencenews.org/blog/wild-things/world-mammal-diversity-has-been-lost-because-humans">suite of prey</a> compared with Yellowstone. Add to this the considerable <a href="http://onlinelibrary.wiley.com/doi/10.1111/ecog.01640/abstract">influence of megaherbivores</a>, like elephants, and you have a complex jigsaw of ecological interactions.</p>
<p>Despite this complexity, the recent increase of large carnivore reintroductions in South Africa provides an ideal opportunity to investigate the relative influence of predators. South Africa is home to a number of <a href="http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1405176806.html">large predator reintroductions</a>. The scientific community is now gaining new insights about the effects these predators have on prey populations and behaviour, and ultimately ecosystems.</p>
<p>In our <a href="http://link.springer.com/article/10.1007%2Fs00265-015-1929-6">research</a> we used the reintroduction of lion and spotted hyena into the <a href="https://www.sanparks.org/parks/addo/">Addo Elephant National Park</a>. The aim was to investigate how these two top predators influence prospective prey species. Specifically, we compared the activity patterns of warthog, kudu, buffalo and elephant in two neighbouring, but separately fenced, sections of Addo. </p>
<p>Based on our research we saw changes in the <a href="http://onlinelibrary.wiley.com/doi/10.1890/11-1770.1/full">behaviour</a> and activities of prospective prey when predators were present. As was seen in Yellowstone, changes in behaviour of one species in the ecosystem can have knock-on effects. The exact nature of these knock-on effects in Addo is still under investigation. </p>
<h2>The impact of lion and spotted hyena</h2>
<p>In the Main Camp section, lion and spotted hyena were reintroduced in <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1022348&fileId=S0030605307001767">2003 and 2004</a>. At the time of the study, these two predators had been absent from the Nyathi section of the park for more than 100 years. </p>
<p>Lion and spotted hyena are active <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2028.2006.00686.x/abstract">predominantly at night</a>.</p>
<p>The results show that when lion and spotted hyena are present, all prospective prey species are most active during the day.</p>
<p>But in the Nyathi section, where predators were absent, kudu and buffalo were more active at night.</p>
<p>One possible consequence of this might be that kudu and buffalo save water and energy by being active at night when it’s cooler. What the long-term consequences of this behaviour might be is, however, not known.</p>
<p>In the presence of predators, kudu and buffalo are active at the hottest time of the day. These activity patterns mirror kudu and buffalo activity patterns elsewhere in the <a href="http://link.springer.com/article/10.1007%2Fs00265-009-0760-3">immediate presence of lions</a>. This behaviour in the presence of predators may have <a href="https://link.springer.com/article/10.1007%2Fs00484-012-0622-y">heat stress</a> implications. This heat stress may reduce <a href="http://www.sciencedirect.com/science/article/pii/S1095643308010209">food intake</a> for African ungulates with long term population consequences.</p>
<p>Elephant and warthog were active during the day regardless of whether lion and spotted hyena were present. Even though warthog spent the night in burrows in both sections, in the presence of lions and spotted hyena, they emerged later and returned earlier thus reducing their activity when lion and spotted hyena are active. </p>
<p>Elephants, which are largely free from <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=345293&fileId=S0952836905007508">lion</a> and <a href="http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1469-7998.2006.00183.x/abstract">spotted hyena</a> predation, had virtually identical activity patterns in the presence and absence of lion and spotted hyena.</p>
<p>Another important outcome is the increased visibility of the prey species for tourism. In the absence of lion only about <a href="http://reference.sabinet.co.za/sa_epublication_article/wild_v33_n1_a3">5% of tourists</a> were fortunate enough to see buffalo, one of the must see big five species, for African game viewing. After the reintroduction of lion, however, <a href="http://www.bioone.org/doi/abs/10.3957/0379-4369-37.2.189?journalCode=sawr">95% of tourists</a> recorded seeing buffalo.</p>
<p>So reintroducing predators has important <a href="http://science.sciencemag.org/content/343/6167/1241484">ecological and evolutionary effects</a> beyond simple predator conservation goals. In addition, the unintended consequence of enhanced game viewing of prey species for tourists may boost the tourism value of areas to which large predators are introduced.</p><img src="https://counter.theconversation.com/content/56216/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Craig Tambling receives funding from National Research Foundation, Claude Leon Foundation and International Foundation for Science. </span></em></p><p class="fine-print"><em><span>Graham Kerley has received funding from the National Research Foundation.</span></em></p>Kudu and buffalo altered their activity when lions and spotted hyena were reintroduced into the areas where these species lived.Craig Tambling, Post Doctoral Fellow Zoology and the Centre for African Conservation Ecology, Nelson Mandela UniversityGraham Kerley, Professor, Zoology & Director: Centre for African Conservation Ecology, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.