首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Invasive grass reduces aboveground carbon stocks in shrublands of the Western US
Authors:BETHANY A BRADLEY  R A HOUGHTON†  JOHN F MUSTARD  STEVEN P HAMBURG‡
Institution:Department of Geological Sciences, Brown University, 324 Brook St., Providence, RI 02912, USA,;Woods Hole Research Center, Falmouth, MA 02540, USA,;Center for Environmental Studies, Brown University, Providence, RI 02912, USA
Abstract:Understanding the terrestrial carbon budget, in particular the strength of the terrestrial carbon sink, is important in the context of global climate change. Considerable attention has been given to woody encroachment in the western US and the role it might play as a carbon sink; however, in many parts of the western US the reverse process is also occurring. The conversion of woody shrublands to annual grasslands involves the invasion of non-native cheatgrass ( Bromus tectorum ) which in turn leads to increased frequency and extent of fires. We compared carbon storage in adjacent plots of invasive grassland and native shrubland. We scaled-up the impact of this ecosystem shift using regional maps of the current invasion and of the risk of future invasion. The expansion of cheatgrass within the Great Basin has released an estimated 8±3 Tg C to the atmosphere, and will likely release another 50±20 Tg C in the coming decades. This ecosystem conversion has changed portions of the western US from a carbon sink to a source, making previous estimates of a western carbon sink almost certainly spurious. The growing importance of invasive species in driving land cover changes may substantially change future estimates of US terrestrial carbon storage.
Keywords:Bromus tectorum            carbon budget  cheatgrass  fire  Great Basin  invasive species  land cover change  woody encroachment
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号