期刊
GLOBAL CHANGE BIOLOGY
卷 21, 期 3, 页码 1226-1235出版社
WILEY
DOI: 10.1111/gcb.12743
关键词
carbon sequestration; Chihuahuan Desert; creosotebush shrubland; desert grassland; ecological state transition; ecosystem services
资金
- National Science Foundation
- USDA Forest Service, Western Wildland Environmental Threat Assessment Center
- NASA [NNX11AG91G]
- NSF-EPSCoR award for Hydrology
- Direct For Biological Sciences
- Division Of Environmental Biology [1440478] Funding Source: National Science Foundation
- NASA [NNX11AG91G, 145513] Funding Source: Federal RePORTER
The replacement of native C-4-dominated grassland by C-3-dominated shrubland is considered an ecological state transition where different ecological communities can exist under similar environmental conditions. These state transitions are occurring globally, and may be exacerbated by climate change. One consequence of the global increase in woody vegetation may be enhanced ecosystem carbon sequestration, although the responses of arid and semiarid ecosystems may be highly variable. During a drier than average period from 2007 to 2011 in the northern Chihuahuan Desert, we found established shrubland to sequester 49g Cm(-2)yr(-1) on average, while nearby native C-4 grassland was a net source of 31g Cm(-2)yr(-1) over this same period. Differences in C exchange between these ecosystems were pronounced - grassland had similar productivity compared to shrubland but experienced higher C efflux via ecosystem respiration, while shrubland was a consistent C sink because of a longer growing season and lower ecosystem respiration. At daily timescales, rates of carbon exchange were more sensitive to soil moisture variation in grassland than shrubland, such that grassland had a net uptake of C when wet but lost C when dry. Thus, even under unfavorable, drier than average climate conditions, the state transition from grassland to shrubland resulted in a substantial increase in terrestrial C sequestration. These results illustrate the inherent tradeoffs in quantifying ecosystem services that result from ecological state transitions, such as shrub encroachment. In this case, the deleterious changes to ecosystem services often linked to grassland to shrubland state transitions may at least be partially offset by increased ecosystem carbon sequestration.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据