Journal of Geographical Sciences ›› 2018, Vol. 28 ›› Issue (5): 611-628.doi: 10.1007/s11442-018-1494-9

• Research Articles • Previous Articles     Next Articles

Response of the water use efficiency of natural vegetation to drought in Northeast China

Dan LIU1,2,3(), Chenglong YU1,2,3(), Fang ZHAO4   

  1. 1. Northeast China Ecological and Meteorological Open Innovation Laboratory, China Meteorological Administration, Harbin 150030, China
    2. Meteorological Academician Workstation of Heilongjiang Province, Harbin 150030, China
    3. Heilongjiang Province Institute of Meteorological Sciences, Harbin 150030, China
    4. College of Agronomy, Ningxia University, Yinchuan 750021, China
  • Received:2017-10-18 Accepted:2018-01-06 Online:2018-03-30 Published:2018-03-31
  • About author:

    Author: Liu Dan (1974-), PhD, specialized in ecological meteorology. E-mail: nefuliudan@163.com

    *Corresponding author: Yu Chenglong (1973-), PhD, specialized in ecological meteorology. E-mail: nefuycl@163.com

  • Supported by:
    Foundation of Northeast China Innovation and Opening Laboratory of Eco-Meteorology, CMA, No.stqx2017zd01;Special Projects of Climate Change of CMA, No.CCSF201512;Foundation of Institute of Atmospheric Environment in Shenyang, CMA, No.2016SYIAE11;National Natural Science Foundation of China, No.41165005

Abstract:

Drought has become a problem that is universally faced by global terrestrial ecosystems. Northeast China is located in a region sensitive to global climate changes, and one of the main impacts of climate changes in Northeast China is manifested as drought in growing seasons. This study analyzes the spatio-temporal evolution law of the water use efficiency (WUE) of the main natural vegetation (i.e., cold-temperate coniferous forests, temperate pine-broad-leaved mixed forests, warm-temperate deciduous broad-leaved forests, and grasslands) in Northeast China based on public MODIS data products, including MCD12Q1, MOD15A2H, MOD16A2, and MOD17A3H, and meteorological data from 2002 to 2013. The influence of drought events on the WUE of different vegetation types and their response to drought events are also investigated. The study findings are as follows: (1) drought in Northeast China frequently occurs in the regions stretching from 114.55°E to 120.90°E, and the percentage of drought area among the forests is lower than that among the grasslands during these years; (2) the annual average WUE of the natural vegetation ranges from 0.82 to 1.08 C/kg-1H2O, and the WUE of forests (0.82 to 1.08 C/kg-1H2O) is universally higher than that of grasslands (0.84 to 0.99 C/kg-1H2O); (3) in 2008, the regions where the WUE in drought conditions is higher than that in normal water conditions account for 86.11% of the study area, and a significant linear positive correlation is found between the WUE in drought conditions and the WUE in normal water conditions, whereas the degree of drought does not influence the WUE of the natural vegetation in an obviously linear manner; and (4) the WUE for the cold-temperate coniferous forests and temperate pine-broad-leaved mixed forests with a high ET or low NPP is more likely to rise in drought conditions; the WUE for the grasslands with a low Evapotranspiration (ET), Net Primary Production (NPP), and Leaf Area Index (LAI) is more likely to rise in drought conditions; and the ET, NPP, and LAI have no significant influence on the WUE for the warm-temperate deciduous broad-leaved forests in drought conditions. This study contributes to improving the evaluation of the influence of drought on natural ecosystems.

Key words: natural vegetation, drought, water use efficiency (WUE)