文献类型：期刊文献

英文题名：Ecosystem water use efficiency in a young plantation in Northern China and its relationship to drought

作者：Ma, Jingyong[1,2] Jia, Xin[1,2] Zha, Tianshan[1,2] Bourque, Charles P-A[1,3] Tian, Yun[1,2] Bai, Yujie[1,2] Liu, Peng[1,2] Yang, Ruizhi[1,2] Li, Cheng[1,2] Li, Chunyi[4] Xie, Jing[5] Yu, Haiqun[5] Zhang, Feng[5] Zhou, Caixian[5]

第一作者：Ma, Jingyong

通信作者：Zha, TS[1]

机构：[1]Beijing Forestry Univ, Sch Soil & Water Conservat, Beijing, Peoples R China;[2]Beijing Forestry Univ, Beijing Engn Res Ctr Soil & Water Conservat, Beijing, Peoples R China;[3]Univ New Brunswick, Fac Forestry & Environm Management, 28 Dineen Dr, Fredericton, NB E3B 5A3, Canada;[4]Chinese Acad Forestry, Inst Wetland Res, Beijing, Peoples R China;[5]Beijing Forestry Carbon Adm, Beijing 100013, Peoples R China

年份：2019

卷号：275

起止页码：1-10

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;Scopus(收录号：2-s2.0-85065543989);WOS:【SCI-EXPANDED(收录号:WOS:000480376400001)】；

基金：This study was supported by grants from National Natural Science Foundation of China (NSFC, Proj. No. 31670710, 31361130340, 31670708), the Fundamental Research Funds for the Central Universities (Proj. No. 2015ZCQ-SB-02). The U.S.-China Carbon Consortium (USCCC) supported this work via helpful discussions and exchange of ideas. We are grateful to Cai Ren and Chuang Jing for his assistance with the instrumentation maintenance and field measurements. We also would like to thank the editors and anonymous reviewers for providing valuable comments and suggestions on the manuscript.

语种：英文

外文关键词：Drought; Ecosystem water use efficiency; Eddy covariance; Evapotranspiration; Gross ecosystem production; Plantation forest

摘要：Climate models predict large climatic variability and more frequent, prolonged droughts in northern China. Still, few studies have examined the seasonal and interannual variation in water use efficiency (WUE) in northern China's young plantations predisposed to drought. Here, variation in WUE was examined in a young plantation in Beijing over a 6-year period (2012-2017) at several timescales. The study was conducted by examining eddy-covariance measurements of gross ecosystem production (GEP) and evapotranspiration (ET). Results showed that the multi-year mean WUE for this young plantation was 1.71 +/- 0.22 g C per kg H2O. Drought reduced WUE in summer, but increased it in autumn, with no apparent effect in spring. Long-term droughts usually had a greater effect on the annual GEP, ET and WUE than short-term droughts. Intense drought was observed to have a long-term legacy effect on ecosystem GEP, ET and WUE of about 3 years. Monthly WUE had a strong positive linear relationship with normalized difference vegetation index (NDVI) and soil volumetric water content (VWC) during the growing season. Seasonal variation in WUE was mainly regulated by the biophysical factors controlling GEP. In contrast, interannual variation in WUE was controlled to a greater extent by vegetation cover (i.e., NDVI), which in turn responded to variation in VWC. These results clearly show the importance of timing and duration of drought in controlling ecosystem WUE. Collectively, WUE was more strongly affected by factors affecting carbon uptake than water consumption. Our findings suggest that future drought, when coupled with increased climate variability, irrigation-support planning and selection of appropriate tree species should be central to afforestation programs in northern China.