• CN 62-1070/P
• ISSN 1000-694X
• 双月刊 创刊于1981年
 中国沙漠  2020, Vol. 40 Issue (5): 120-129    DOI: 10.7522/j.issn.1000-694X.2020.00005

1.北京林业大学，水土保持学院/宁夏盐池毛乌素沙地生态系统国家定位观测研究站，北京 100083
2.北京林业大学，林业生态工程教育部工程中心，北京 100083
Spatial-temporal patterns of vegetation water use efficiency in the Mu Us Desert
Jiaoyue Wanga(),Shugao Qina2,Yuqing Zhanga2()
a.School of Soil and Water Conservation/Yanchi Research Station // b. MOE Engineering Research Center of Forestry Ecological Engineering，Beijing Forestry University，Beijing 100083，China
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Abstract:

Water use efficiency （WUE） is a key proxy for linking carbon and water exchange processes in terrestrial ecosystems. Understanding the spatial-temporal variations in WUE helps to evaluate the adaptability of vegetation to local environmental conditions. This study estimated the vegetation WUE in the Mu Us Desert during 2001-2016 using remote-sensing data and meteorological observations. Carbon sequestration （i.e.， net primary productivity， NPP） was estimated based on the Carnegie-Ames-Stanford Approach （CASA） model， while water consumption （i.e.， evapotranspiration， ET） was obtained from the MODIS product. The spatial-temporal patterns of WUE and their responses to meteorological factors were investigated by trend analysis and correlation analysis， respectively. The results showed that： （1） the mean annual WUE across the Mu Us Desert was 0.62 gC·mm-1·m-2 with a trend of decrease from the east to the west， and among different vegetation types， the values of WUE ranked in the order of cultivated vegetation>shrub>meadow>steppe>desert； （2） WUE increased at the rate of 0.009 gC·mm-1·m-2·yr-1 during the study period， especially significantly in eastern， and the increase in WUE mainly attributed to the rapid rise in NPP； and （3） the relationships between WUE and meteorological factors followed a sequence of solar radiation， precipitation， wind speed， and air temperature from strong to weak， and there were relatively insignificant relationships between WUE and meteorological factors in the western part of the Mu Us Desert. The study highlight that the revegetation programs implemented in the Mu Us Desert have achieved good outputs that both NPP and WUE have increased since 2001， which contributed to the improvement of local ecological environment； however， in the central and western part of the Mu Us Desert with poor condition of water and heat， the mismatch between revegetation magnitude and water should be paid more attention.

Key words: water use efficiency （WUE    CASA model    meteorological factors    Mu Us Desert

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