Chin J Plan Ecolo ›› 2017, Vol. 41 ›› Issue (5): 506-518.DOI: 10.17521/cjpe.2016.0142

Special Issue: 全球变化与生态系统

• Research Articles • Previous Articles     Next Articles

Spatio-temporal characteristics of evapotranspiration and water use efficiency in grasslands of Xinjiang

Xiao-Tao HUANG1,2, Ge-Ping LUO1,*   

  1. 1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China;

    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2017-05-10 Published:2017-06-22
  • Contact: Ge-Ping LUO
  • About author:

    KANG Jing-yao(1991-), E-mail:


Aims Xinjiang is located in the hinterland of the Eurasian arid areas, with grasslands widely distributed. Grasslands in Xinjiang provide significant economic and ecological benefits. However, research on evapotranspiration (ET) and water use efficiency (WUE) of the grasslands is still relatively weak. This study aimed to explore the spatio-temporal characteristics on ET and WUE in the grasslands of Xinjiang in the context of climate change.Methods The Biome-BGC model was used to determine the spatio-temporal characteristics of ET and WUE of the grasslands over the period 1979-2012 across different seasons, areas and grassland types in Xinjiang.Important findings The average annual ET in the grasslands of Xinjiang was estimated at 245.7 mm, with interannual variations generally consistent with that of precipitation. Overall, the value of ET was lower than that of precipitation. The higher values of ET mainly distributed in the Tianshan Mountains, Altai Mountains, Altun Mountains and the low mountain areas on the northern slope of Kunlun Mountains. The lower values of ET mainly distributed in the highland areas of Kunlun Mountains and the desert plains. Over the period 1979-2012, average annual ET was 183.2 mm in the grasslands of southern Xinjiang, 357.9 mm in the grasslands of the Tianshan Mountains, and 221.3 mm in grasslands of northern Xinjiang. In winter, ET in grasslands of northern Xinjiang was slightly higher than that of Tianshan Mountains. Average annual ET ranked among grassland types as: mid-mountain meadow > swamp meadow > typical grassland > desert grassland > alpine meadow > saline meadow. The highest ET value occurred in summer, and the lowest ET value occurred in winter, with ET in spring being slightly higher than that in autumn. The higher WUE values mainly distributed in the areas of Tianshan Mountains and Altai Mountains. The lower WUE values mainly distributed in the highland areas of Kunlun Mountains and part of the desert plains. The average annual WUE in the grasslands of Xinjiang was 0.56 g·kg-1, with the seasonal values of 0.43 g·kg-1 in spring, 0.60 g·kg-1 in summer, and 0.48 g·kg-1 in autumn, respectively. Over the period 1979-2012, the values of WUE displayed significant regional differences: the average values were 0.73 g·kg-1 in northern Xinjiang, 0.26 g·kg-1 in southern Xinjiang, and 0.69 g·kg-1 in Tianshan Mountains. There were also significant differences in WUE among grassland types. The values of WUE ranked in the order of mid-mountain meadow > typical grassland > swamp meadow > saline meadow > alpine meadow > desert grassland.

Key words: evapotranspiration, water use efficiency, climate change, Biome-BGC, arid area