Scientists have been studying natural sources of methane for decades but hadnt regarded plants as a producernotes Frank Kepplera geochemist at the Max Planck Institute for Nuclear Physics in HeldelbergGermany.Now Keppler and his colleagues find that plantsfrom grasses to treesmay also be sources of the greenhouse gas.This is really surprisingbecause most scientists assumed that methane production requires an oxygen-free environment. In its experimentsKepplers team used sealed chambers that contained the same concentration of oxygen that Earths atmosphere has.They measured the amounts of methane that were released by both living plants and dried plant materialsuch as fallen leaves. Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour.Methane emissions tripled when living and dead plant was exposed to sunlight. The new finding is an interesting observation, says Jennifer Y.Kinga biogeochemist at the University of Minnesota in St.Paul3.Because some types of soil microbes consume methanethey may prevent plant-produced methane from reaching the atmosphere.Field tests will be needed to assess the plants influenceshe notes.
下一篇: 职称英语理工类的阅读理解习题(5)
冀教版英语一下(一起)《Unit 1 My classroom》ppt课件
冀教版(一起)二下《lesson 26 Cars, buses and bikes》ppt课件
北师大版(三起)六上《unit 2 Mocky’s bad day》ppt课件2
冀教版英语一下(一起)《Unit 4 Lesson28 Let’s go shopping》ppt课件包
北师大版(三起)六上《Unit 3 School sports day》ppt课件2
冀教版(一起)一下《Lesson 8 Jenny’s Family》ppt课件
冀教版英语一下(一起)《Unit 1 Lesson3 Places in my school》ppt课件
冀教版(一起)二下《lesson 21 Let’s visit the neighbours.》ppt课件
冀教版(一起)二下《Lesson 13 I count》ppt课件
北师大版(三起)六上《Unit 1 Ann’s dream》ppt课件
冀教版(一起)一下《Lesson 21 At the Shop》ppt课件
冀教版(一起)二下《lesson 17 It’s Saturday》ppt课件
冀教版(一起)二下《lesson 22 Playing at home》ppt课件
冀教版(一起)二下《Lesson 15 Help your family!》ppt课件
北师大版(三起)六上《unit 2 Mocky’s bad day》ppt课件3
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2016秋北师大版(三起)六上Unit 2《An Accident》ppt课件1
冀教版(一起)二下《lesson 4 Washroom, gym》ppt课件
冀教版(一起)二下《Lesson 9 My big family》ppt课件1
北师大版(三起)六上《unit 2 Mocky’s bad day》ppt课件
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北师大版(三起)六上《Unit 4 Mocky’s birthday》ppt课件
冀教版(一起)一上《Lesson 3 How Are You》ppt课件
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冀教版(一起)一上《Lesson 3 How Are You》ppt课件1
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