Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (5): 434-443.DOI: 10.17521/cjpe.2020.0204

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Climatic factors drive the aboveground ecosystem functions of alpine grassland via soil microbial biomass nitrogen on Qinghai-Xizang Plateau

Wang Yi1,Jian SUN2,Chong ChongYe3,Tao Zeng1   

  1. 1. College of Earth Sciences, Chengdu University of Technology Chengdu University of Technology
    2.
    3. School of Civil Engineering and Geomatics, Southwest Petroleum University
  • Received:2020-06-22 Revised:2020-11-13 Online:2021-04-20 Published:2020-12-09
  • Contact: Jian SUN
  • Supported by:
    Second Tibetan Plateau Scientific Expedition and Research Program

Abstract: Aims In recent years, under the background of climate change and human activities, the trend of biodiversity loss is increasing, which could bring serious consequences to ecosystem functions. At present, the research on ecosystem function ignores the important driving role of carbon and nitrogen nutrient cycling process of soil and microorganism on the above ground ecosystem function. Any change of soil carbon and nitrogen factors and microorganism may change the ability of belowground community to maintain the aboveground ecosystem functions. Our aim was to explore the driving factors and key mechanism to abovegroud ecosystem functions (AEF) in alpine grassland. Methods From July to August 2015, we conducted a transect survey in alpine grasslands to measure plant community and soil properties across Qinghai-Xizang Plateau, with a total of 115 sample sites. Based on the aboveground biomass, leaf carbon, nitrogen and phosphorus, the aboveground ecosystem function was calculated, and the effects of key elements such as soil organic carbon, total nitrogen and biomass on the aboveground ecosystem function were analyzed. Combined with annual total precipitation and temperature, we explored mainly drivers and mechanism affecting the AEF. Important findings Precipitation has a greater impact on aboveground ecosystem functions, while temperature has a relatively low impact on aboveground ecosystem functions. Annual total precipitation, soil microbial nitrogen and aridity index had the higher relative importance to aboveground ecosystem functions with the values of 21.1%, 10.9% and 10.1%, respectively. The findings indicated that soil properties might play more important roles than plant community and productivity to aboveground ecosystem functions. Under the promoting role of climate factors on soil nutrients cycling and microorganisms, soil microbial biomass nitrogen plays an important role in regulating AEF of alpine grassland, Qinghai-Xizang Plateau.

Key words: aboveground ecosystem functions, alpine grassland, soil total nitrogen, microbial biomass nitrogen, Qinghai-Xizang Plateau