JOURNAL OF NATURAL RESOURCES ›› 2018, Vol. 33 ›› Issue (8): 1351-1362.doi: 10.31497/zrzyxb.20170726

• Resource Ecology • Previous Articles     Next Articles

Spatial Variation of Soil Moisture and Species Diversity Patterns along a Precipitation Gradient in the Grasslands of the Loess Plateau

ZHANG Qin-di1,2, WEI Wei1,3, CHEN Li-ding1,3, YANG Lei1,3   

  1. 1. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;
    2. College of Life Sciences, Shanxi Normal University, Linfen 041000, China;
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-07-21 Revised:2017-11-04 Online:2018-08-20 Published:2018-08-20
  • Supported by:
    National Natural Science Foundation of China,No. 41390462 and 41601027;the National Key Research and Development Program of China, No. 2016YFC0501701;the National Advanced Project of the Twelfth Five-year Plan of China, No. 2015BAC01B02

Abstract: The spatial variations of soil moisture and biodiversity have become central issues in ecohydrology which contribute to the understanding of the response of terrestrial ecosystem to precipitation change in water-limited areas. Based a precipitation gradient (250-550 mm) in the Loess Plateau, vertical soil moisture (0-3 m) and species diversity at 47 grassland sites across a southeast-northwest transect were surveyed. The spatial variations of soil moisture and species diversity were evaluated, and the tradeoff between them along the precipitation gradient was quantified. Results showed great variation of soil moisture in the vertical profiles along the precipitation gradient. Significant linear correlation existed between the average soil moisture of the profile and the mean annual precipitation, and the soil moisture in the shallow layer (0-1 m) was affected more greatly by mean annual precipitation. The Patrick index and Shannon-Wiener diversity index also showed positive linear correlation with precipitation, however, Pielou evenness index did not (P>0.05). The linear piece-wise quantile regression was applied to determine the inflection points of the response of tradeoff between species diversity and soil moisture to the precipitation gradient. It revealed obvious trend of the tradeoff along the precipitation gradient. The inflection point of the tradeoff was detected at the mean annual precipitation of 370 mm. Under the 370 mm annual mean precipitation, soil moisture constrains species diversity in the relatively arid regions, while the synergy between soil moisture and species diversity exists in the relatively humid regions in this study. This suggests species maintaining in the relatively arid regions is at the cost of soil water. The results demonstrate that the precipitation gradient determined the tradeoff between soil moisture and species diversity in the grasslands of the Loess Plateau. Consequently, this tradeoff could be an ecological indicator and tool for restoration management in the Loess Plateau.

Key words: Loess Plateau, precipitation gradient, soil moisture, species diversity, tradeoff analysis

CLC Number: 

  • Q948