文献类型：期刊文献

英文题名：Responses of greenhouse gas fluxes to climate extremes in a semiarid grassland

作者：Li, Linfeng[1] Fan, Wenyu[1] Kang, Xiaoming[2] Wang, Yanfen[1] Cui, Xiaoyong[1] Xu, Chengyuan[3] Griffin, Kevin L.[4] Hao, Yanbin[1]

第一作者：Li, Linfeng

通信作者：Cui, XY[1];Hao, YB[1]

机构：[1]Univ Chinese Acad Sci, Coll Life Sci, Beijing 100049, Peoples R China;[2]Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China;[3]Cent Queensland Univ, Sch Med & Appl Sci, Bundaberg, Qld 4670, Australia;[4]Columbia Univ, Lamont Doherty Earth Observ, Dept Earth & Environm Sci, Palisades, NY 10964 USA

年份：2016

卷号：142

起止页码：32-42

外文期刊名：ATMOSPHERIC ENVIRONMENT

收录：;EI(收录号：20163102657874);Scopus(收录号：2-s2.0-84979220934);WOS:【SCI-EXPANDED(收录号:WOS:000383293100004)】；

基金：Financial support was provided by the Chinese Academy of Sciences (Grant No. KJRH2015-010), Special Funds for Sciences and Education Fusion of University of Chinese Academy of Science, the National Nonprofit Institute Research Grant of CAFINT (Grant No. CAFYBB2014QB026), the National Youth Science Foundation of China (Grant No. 31300417). We greatly appreciate the assistance from Inner Mongolia Grassland Ecosystem Research Station and the Chinese Academy of Sciences.

语种：英文

外文关键词：Extreme drought; Heat wave; CO2 flux; CH4 flux; N2O flux; Soli water content

摘要：Climate extremes are expected to increase in frequency and intensity as a consequence of anthropogenic climate change attributed to the rise of atmospheric concentrations of greenhouse gases (GHGs). However, studies on the impacts of climate extremes on terrestrial ecosystems are limited. Here, we experimentally imposed extreme drought and a heat wave (similar to 60-year recurrence) to investigate their effects on GHGs fluxes of a semiarid grassland in China. We estimated a 16% and 38% percent reduction in net ecosystem CO2 uptake caused by the heat wave and drought respectively, but via different mechanisms. Drought reduced gross ecosystem productively (GEP) and to a lower extent ecosystem respiration (ER). By contrast, the simulated heat wave suppressed only GEP while ER remained stable. The climate extremes also created a legacy effect on GEP and NEE lasting until the end of the growing season, whereas ER recovered immediately. Although CH4 and N2O fluxes were unaffected by the heat wave, drought promoted CH4 uptake and suppressed N2O emission during the treatment period. The effect of drought on GHGs fluxes generally overwhelmed that of the heat wave treatment, and there were no interactive effects of these two types of climate extremes. Our results showed that responses of ecosystem GHGs exchange to climate extremes are strongly regulated by soil moisture status. In conclusion, future amplification of climate extremes could decrease the sink for GHGs, especially CO2, in this semiarid grasslands. (C) 2016 Elsevier Ltd. All rights reserved.