Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1029/2010JG001348 |
Carbon dioxide exchange in a semidesert grassland through drought-induced vegetation change | |
Scott, Russell L.1; Hamerlynck, Erik P.1; Jenerette, G. Darrel3; Moran, M. Susan1; Barron-Gafford, Greg A.2 | |
通讯作者 | Scott, Russell L. |
来源期刊 | JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
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ISSN | 2169-8953 |
EISSN | 2169-8961 |
出版年 | 2010 |
卷号 | 115 |
英文摘要 | Global warming may intensify the hydrological cycle and lead to increased drought severity and duration, which could alter plant community structure and subsequent ecosystem water and carbon dioxide cycling. We report on the net ecosystem exchange of carbon dioxide (NEE) of a semidesert grassland through a severe drought which drove succession from native bunchgrasses to forbs and to eventual dominance by an exotic bunchgrass. We monitored NEE and energy fluxes using eddy covariance coupled with meteorological and soil moisture variables for 6 years at a grassland site in southeastern Arizona, USA. Seasonal NEE typically showed a springtime carbon uptake after winter-spring periods of average rainfall followed by much stronger sink activity during the summer rainy season. The two severe drought years (2004 and 2005) resulted in a net release of carbon dioxide (25 g C m(-2)) and widespread mortality of native perennial bunchgrasses. Above average summer rains in 2006 alleviated drought conditions, resulting in a large flush of broad-leaved forbs and negative total NEE (-55 g C m(-2) year(-1)). Starting in 2007 and continuing through 2009, the ecosystem became increasingly dominated by the exotic grass, Eragrostis lehmanniana, and was a net carbon sink (-47 to -98 g C m(-2) year(-1)) but with distinct annual patterns in NEE. Rainfall mediated by soils was the key driver to water and carbon fluxes. Seasonal respiration and photosynthesis were strongly dependent on precipitation, but photosynthesis was more sensitive to rainfall variation. Respiration normalized by evapotranspiration showed no interannual variation, while normalized gross ecosystem production (i.e., water use efficiency) was low during drought years and then increased as the rains returned and the E. lehmanniana invasion progressed. Thus, when dry summer conditions returned in 2009, the potential for ecosystem carbon accumulation was increased and the ecosystem remained a net sink unlike similar dry years when native grasses dominated ecosystem structure. |
类型 | Article |
语种 | 英语 |
国家 | USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000282322500001 |
WOS关键词 | NET ECOSYSTEM EXCHANGE ; INTRODUCED LEHMANN LOVEGRASS ; WOODY-PLANT ENCROACHMENT ; SEMIARID GRASSLAND ; SEASONAL-VARIATION ; NONNATIVE GRASSES ; EDDY-COVARIANCE ; ERAGROSTIS-LEHMANNIANA ; DESERT GRASSLAND ; GAS-EXCHANGE |
WOS类目 | Environmental Sciences ; Geosciences, Multidisciplinary |
WOS研究方向 | Environmental Sciences & Ecology ; Geology |
来源机构 | University of Arizona |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/165245 |
作者单位 | 1.USDA ARS, SE Watershed Res Ctr, Tucson, AZ 85719 USA; 2.Univ Arizona, Tucson, AZ 85721 USA; 3.Univ Calif Riverside, Dept Bot & Plant Sci, Riverside, CA 92521 USA |
推荐引用方式 GB/T 7714 | Scott, Russell L.,Hamerlynck, Erik P.,Jenerette, G. Darrel,et al. Carbon dioxide exchange in a semidesert grassland through drought-induced vegetation change[J]. University of Arizona,2010,115. |
APA | Scott, Russell L.,Hamerlynck, Erik P.,Jenerette, G. Darrel,Moran, M. Susan,&Barron-Gafford, Greg A..(2010).Carbon dioxide exchange in a semidesert grassland through drought-induced vegetation change.JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,115. |
MLA | Scott, Russell L.,et al."Carbon dioxide exchange in a semidesert grassland through drought-induced vegetation change".JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 115(2010). |
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