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

• Research Articles • Previous Articles     Next Articles

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

WANG Yi1,2, SUN Jian2,*(), YE Chong-Chong2,3, ZENG Tao1,*()   

  1. 1College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
    2Key Laboratory of Observation and Simulation of Ecological Networks, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    3School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu 610500, China
  • Received:2020-06-22 Accepted:2020-10-22 Online:2021-05-20 Published:2020-12-09
  • Contact: SUN Jian,ZENG Tao


Aims In recent years, under the background of climate change and human activities, the trend of biodiversity loss is increasing. Such accelerated loss in biodiversity could bring serious consequences to ecosystem functions. At present, the research on ecosystem function ignores the important driving role of carbon and nitrogen cycling in soil and microorganism on the above ground ecosystem functions. Any changes of soil carbon, nitrogen and microorganism may affect the ability of belowground community, which can have substantial effects on the aboveground ecosystem functions. Our aim was to explore the driving factors and key mechanism of 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 Qingzang Plateau. There were in total 115 sample sites. The aboveground ecosystem function was calculated based on the aboveground biomass, leaf carbon, leaf nitrogen and leaf phosphorus. The effects of key elements such as soil organic carbon, total nitrogen and biomass on the aboveground ecosystem function were analyzed. Combined with mean annual precipitation and air temperature, we explored important drivers of AEF and related mechanisms.
Important findings Precipitation has a greater impact on aboveground ecosystem functions, while air temperature has a minor impact. Mean annual precipitation, soil microbial nitrogen content and aridity index had relative higher importance to aboveground ecosystem functions. Specificially, mean annual precipitation, soil microbial nitrogen content and aridity index accounted for the variations 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. Considering the cascading impacts of climate factors on soil nutrients cycling and microorganisms, soil microbial biomass nitrogen content plays an important role in regulating AEF of alpine grassland, Qingzang Plateau.

Key words: aboveground ecosystem function, alpine grassland, soil total nitrogen, soil microbial biomass nitrogen, Qingzang Plateau