SSS 2008-02-13(在线收听) |
This is Scientific American's 60-Second Science. I am Karen Hopkin. This'll just take a minute. Seems like every other week brings news that global warming is gonna be bad for some poor animal or other. But plants? Well, I guess I was thinking that plants would welcome the heat. I mean, global warming is caused by greenhouse gases. And plants live in greenhouses. So everyone’s happy. Well, according to a new study, published in the February 12 issue of the Proceedings of the National Academy of Sciences, I was wrong. Or at least not quite right. Because plants, too, are likely to face problems as the earth heats up. And their biggest problem may be: insects. Scientists were looking at the fossilized remains of leaves that fell off trees about 55 million years ago. At that time, the planet was undergoing a period of warming. The scientists found that as the temperatures rose, the leaves looked more…nibbled. Seems that with more CO2 in the atmosphere, plants take up more carbon. That actually makes their leaves less nutritious for plant-munching bugs—so the insects just eat more. So, a warmer planet will be home to some hungry bugs. Which I dare say will not please the trees. Or anyone else who relies on plants for food—which includes, ultimately, all of us. Thanks for the minute, for Scientific American's 60-Second Science. I am Karen Hopkin. |
原文地址:http://www.tingroom.com/lesson/sasss/2008/2/98604.html |