Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (6): 490-500.DOI: 10.17521/cjpe.2019.0006

• Research Articles • Previous Articles     Next Articles

Spatio-temporal characteristics of vegetation water use efficiency and its relationship with climate factors in Tianshan Mountains in Xinjiang from 2000 to 2017

Aizezitiyuemaier MAIMAITI1,Yusufujiang RUSULI1,2,*(),HE Hui1,Baihetinisha ABUDUKERIMU1   

  1. 1 Laboratory of Information Integration and Ecological Safety, Institute of Geographical Science and Tourism, Xinjiang Normal University, ürümqi 830054, China;
    2 Xinjiang Key Laboratory of Lake Environment and Resources in Arid Zone, ürümqi 830054, China;
  • Received:2019-01-08 Revised:2019-06-12 Online:2019-06-20 Published:2019-09-30
  • Contact: Yusufujiang RUSULI
  • Supported by:
    Supported by the National Natural Science Foundation of China(U1703341);Supported by the National Natural Science Foundation of China(41764003)

Abstract:

Aims Water use efficiency (WUE) is a key index to measure the coupling degree of carbon and water cycle in ecosystems. The WUE of vegetation in Tianshan Mountains in Xinjiang and the north and south sites of the main oasis was estimated and then the spatio-temporal distribution of vegetation WUE was analyzed to explore its influencing factors, which will be of great significance to the protection of ecosystem and the rational utilization and development of agricultural water resources in this region. Methods This study used data from moderate-resolution imaging spectroradiometer (MODIS), meteorological and land use type data to estimate the vegetation WUE. The spatio-temporal characteristics of vegetation WUE were analyzed in Tianshan Mountains in Xinjiang over the last 18 years, and the relationship of WUE with climatic factors was evaluated. Important findings The results indicated that: (1) From 2000 to 2017, the average annual vegetation WUE for Tianshan Mountains in Xinjiang was 1.11 g·mm -1·m -2, ranging from 0.84 to 1.34 g·mm -1·m -2. As a whole, the annual decrease trend of vegetation WUE was 0.014 1 g·mm -1·m -2·a -1, and vegetation WUE showed a strong vertical zonality in Tianshan Mountains in Xinjiang, as indicated by the decrease with the altitude above 1 000 m. (2) The vegetation WUE in Tianshan Mountains in Xinjiang showed a unimodal change pattern with significant seasonal difference, in order of summer > spring > autumn > winter. (3) Correlation analysis and statistical results indicated that the dynamic change of vegetation WUE in Tianshan Mountains in Xinjiang was closely related to temperature and rainfall. The regions with vegetation WUE changes resulting from non-climate factors accounted for 39.26% in Tianshan Mountains in Xinjiang. However, the factors of temperature and precipitation contributed to the change of vegetation WUE as 33.23% and 8.57%, respectively. On the other hand, the combination of temperature and precipitation with heavy impact and light impact contributed to WUE by 5.63% and 13.13%, respectively. Overall, temperature played the most important role among all climate factors in the changes in vegetation WUE. (4) The WUE of paddy field and dryland decreased continuously with time, and these areas were mainly affected by non-climatic factors, suggesting the irrationality in local human activities.

Key words: water use efficiency, vegetation, temporal and spatial distribution, climate factor, Tianshan Mountains in Xinjiang