B13F-0677
Water Use Efficiency of China’s Terrestrial Ecosystems and Responses to Drought

Monday, 14 December 2015
Poster Hall (Moscone South)
Yibo Liu1, Jingfeng Xiao2, Weimin Ju3, Yanlian Zhou3, Shaoqiang Wang4 and Xiaocui Wu5, (1)NUIST Nanjing University of Information Science and Technology, Nanjing, China, (2)University of New Hampshire Main Campus, Durham, NH, United States, (3)Nanjing University, Nanjing, China, (4)Institute Of Geographic Scienc, Beijing, China, (5)University of Oklahoma, Norman, OK, United States
Abstract:
Yibo Liu1, 2, Jingfeng Xiao2, Weimin Ju3, Yanlian Zhou4, Shaoqiang Wang5, Xiaocui Wu3

1 Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China,

2Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA,

3 International Institute for Earth System Sciences, Nanjing University, Nanjing, 210023, China,

4 School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China,

5 Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China

Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China’s terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg-1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. “Turning-points” were observed for southern China where moderate and extreme drought reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.  

Keywords: water use efficiency (WUE), drought, carbon sink, ecosystem model, China 

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