字幕列表 影片播放 列印英文字幕 We had been looking at the bottoms of trees, as foresters, for over a century, and nobody ever knew the top was so different from the bottom. Located hundreds of feet above the ground in the canopies of forests is a unique ecosystem that is home to a potential cure for some of the world's deadliest diseases, microscopic tardigrades, and temporarily, this group of daredevil researchers. With the advent of ropes and a few slingshots that I invented along the way, we went to the mid-canopy and we went to the upper canopy, which were really new exploration opportunities. Dr. Meg Lowman pioneered forest exploration when all there was to use were cranes, hot air balloons, and walkways. Now, that toolkit is expanding, which is essential to help combat threats such as deforestation and drought. Suddenly we have drones, and we also have LiDAR, and some of the other aerial technologies that are giving us incredible, broad brush strokes of things like canopy drought, distribution of canopy vines, or certain species of trees that we're trying to track that make it really tough to do, tree after tree, from the ground. One of the areas of Meg's expertise involves the close relationship between insects and plants in the rainforest. I have to learn a lot about both. I do focus on the tree as a system, and the tree as a support for so many other types of life in the rainforest. But I do focus a lot on insects, because they tend to be the dominant herbivore, and there are millions of insects up there, and they are beautiful and gorgeous. The levels of light and rain hitting the top of these forests cause canopies to be hotspots for biodiversity, accounting for likely fifty percent of all land-based life on Earth. - Of that fifty percent life on Earth, probably only ten percent has been seen or discovered by that handful of us that explore the canopy. How many species are in the rainforest? Maybe there are 5 million. But it truly is a guessing game, because maybe we've missed a whole group. And I think water bears is a good example. That's a whole phylum that nobody really explored until about the last three or four years when I partnered with a water bear taxonomist. We can't even count those creatures when we're up there, because we can't see them with our naked eye. These water bears, or tardigrades, are tiny: roughly half a millimeter. These creatures are most likely carried to these towering trees by wind. If these extremophiles do not find their environment to be satisfactory, they can enter a stage known as cryptobiosis, curling up into a ball to survive extreme conditions for extended periods of time without food or water, and coming back to life when conditions have improved. New species of tardigrades continue to be discovered and analyzed, given that their cellular construction could reveal clues to radiation protection, and their genetics could lead to answers surrounding resiliency. This is just one of the areas that Meg comes across in her work with trees and insects that underscores how important this resource can be for humans. In a few cases, pharmaceutical companies have made that magical link between plants and medicines. And so it's given me a really wonderful ability to work with the local shaman and the villagers in a lot of countries where the medicinal value of the trees is so important. The leaves that aren't eaten by insects tend to be the ones that have sequestered chemical compounds that can in turn be turned into medicines. We now realize we can use the insect damage to figure out which trees might have more medicinal values. Meg's research has even more urgency, especially if the rate of deforestation continues at the current pace. Using satellite analysis, NASA predicts that in just 40 years, about a billion hectares of rainforest land, about the size of Europe, will have disappeared. In 100 years, rainforests will be gone altogether. Forests are essential to our life. We have so many easy ways of connecting ourselves to trees. I mentioned medicines, fruits, home to biodiversity. Soil conservation. Carbon storage is a huge one. It's hard to sell people on the fact that they should keep millions of creatures alive when they probably can't understand their importance value. I think a good analogy is that in an airplane there are a lot of redundant screws, and maybe you don't need every single one to fly the plane, but at some point, if they keep dropping off of the machine, it's not going to work anymore. We know that each species has a role in this ecosystem, and we need to keep that system healthy. How many can we lose? Probably some, but not all. And where is that tipping point? We're not really sure. So the more that we can protect those species, the better off we are. For more episodes of Science in the Extremes, check out this one right here. Don't forget to subscribe and come back to Seeker for more episodes. Thanks for watching!
B1 中級 美國腔 可以教给我们有关雨林中的生活的信息(What Tardigrades Can Teach Us About Life in the Rainforest) 7 1 joey joey 發佈於 2021 年 04 月 16 日 更多分享 分享 收藏 回報 影片單字