Subtitles section Play video Print subtitles Buckle up, everyone. Because I just learned something weird, and now you all need to know it, too. I was on a call the other day with a woman named Emily Fairfax. And she knows a lot about beavers. Yes, beavers. And at one point, she just casually mentions, "A weird period of beaver relocation in the 40s where we dropped them out of airplanes." I'm sorry. What? "There's this absolutely absurd video." "You can find it on YouTube from Idaho Fish and Game." "Now into the air, and down, they swing." "The box opens, and a most unusual and novel trip ends for Mr. Beaver." Okay, the method is super questionable. But the Idaho Department of Fish and Game did this to relocate 76 beavers away from humans and into a remote location where there were no roads. Because beavers build dams, structures that completely alter the landscape. But now, research has found that beavers and their dams do so much more than flood the forest. As the planet continues to warm they might also be vital in cooling parts of it down. So when beavers move into a stream, their very first order of business is to build that dam to start making a little bit of a safe habitat for themselves. They start with some logs or stones to secure the structure. After that, they'll keep piling sticks, stones, and mud over and over again until water starts to pool behind it. As flowing water pushes against the dam, it begins to carve out a deep pool, which is great for the beaver. Because on land, "they're pretty unfortunately awkward." But once they get into the water, that's where they really shine and excel. But, it's also ideal for other species. Because deeper water tends to be much cooler than water at the surface. So if you're a fish and it's a really hot day, you can go down into one of these deep pools, and just hunker down at the bottom, where the water is coolest and has the least sunlight affecting it. The dam also forces circulation. As water hits the dam, some of it is forced into the soil, where it mixes with cold ground water before resurfacing. As a result, one study found that water near beaver dams is up to 4 degrees Fahrenheit (2.3 degrees Celsius) cooler than water elsewhere. This comfortable little pond is the first defense against predators. But beavers will also dig out canals into the surrounding land, which function as a small highway system for them. All this tampering with the stream spreads the water around the area. As that water evaporates, the water vapor chills the air. At one of my sites in central California, I went to visit on a particularly hot day. It was 107 Fahrenheit (42 Celsius). And then I get into the complex and I hold up the temperature probe and I'm like wow it's 91 (33 Celsius). We lost almost 15 degrees of air temperature just going into this beaver complex. The area becomes a wetland ecosystem, and on first glance, it's a total mess with branches, plants, and water everywhere. And that's a good thing. A river or a riverscape should be very complex, very messy. And it's that complexity that makes them so resilient to climate change and all sorts of other disturbances. And that resiliency is increasingly important. In the summer of 2022, heatwaves and fires plagued parts of Europe and the US. As the climate crisis worsens, we can expect these events to increase. Beavers, it turns out, might be able to help. Because these wetland ecosystems are especially important in areas that are prone to fire or drought. Dams slow water down and allow it to seep deep into the Earth, which provides a source of groundwater for humans. It also keeps the surrounding land wet, and wetter land is less likely to burn. This is an image from Idaho in 2018 when 65,000 acres were scorched by wildfire. This green patch in the middle is a wetland created by a beaver dam. Emily and a colleague studied the effects of this in 2020 and found repeated evidence that beaver dams create firebreaks. Providing a safe place for animals to go when wildfires break out. That was the first study in the scientific literature that said beaver ponds are too wet to burn in many cases. Beavers have had bad PR. They're often considered annoying pests because wetland creation is so messy. When a dam is built in the wrong place, it can flood roadways or homes. And previously, the solution was extermination. But that seems to be changing. California, for example, just passed a bill that requires state sponsored beaver-relocation. Don't worry, they won't be dropping them out of planes. What we're learning is that beavers do some of the best engineer work for climate resiliency. We just have to let them. We've got to let go of a little bit of control. Especially once a beaver starts building like what was a pretty cute little stream becomes this super wild, messy wetland. Like, that's good. Remember that that is good. We want it to be messy.
B1 Vox beaver dam water idaho messy Why beavers matter as the planet heats up 42299 278 林宜悉 posted on 2022/11/17 More Share Save Report Video vocabulary