Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (1): 50-65.DOI: 10.17521/cjpe.2017.0252

Special Issue: 青藏高原植物生态学:群落生态学

• Research Articles • Previous Articles     Next Articles

Nonlinear responses of productivity and diversity of alpine meadow communities to degradation

CHEN Ning1,2,ZHANG Yang-Jian1,3,4,ZHU Jun-Tao1,*(),LI Jun-Xiang5,LIU Yao-Jie1,2,ZU Jia-Xing1,2,CONG Nan1,HUANG Ke1,WANG Li5   

  1. 1 Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 China

    2 University of Chinese Academy of Sciences, Beijing 100190, China

    3 CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China

    4 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China

    5 Peking University Shenzhen Graduate School, Shenzhen 518055, China
  • Online:2018-01-20 Published:2018-03-08
  • Contact: ZHU Jun-Tao ORCID:0000-0002-3506-1247
  • Supported by:
    Supported by the National Key Research and Development Project of China(2016YFC0501802);Supported by the National Key Research and Development Project of China(2017YFA0604802);the National Natural Science Foundation of China(41571195);the National Natural Science Foundation of China(41501103)

Abstract:

Aims The alpine meadow degradation could have profound effects on the grassland productivity. The aim of our study is to clarify the dynamic response of community productivity and species diversity in the process of alpine meadow degradation.

Methods In the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Northern Tibetan Grassland Ecosystem Research Station (Nagqu station), we conducted stages experiments with multiple degradation levels: control, mild degraded meadow, moderate degraded meadow, severe degraded meadow and serious sandy meadow.

Important findings The response of aboveground biomass to alpine meadow degradation showed a linear or nonlinear increased response patterns, but the belowground biomass and total biomass decreased nonlinearly. As observed in measurement of aboveground biomass, Margalef index, Simpson index, Shannon-Wiener index and Pielou evenness index also exhibit a nonlinear increased response to degradation. The results of structural equation models showed that belowground biomass has a positive relationship with soil carbon content (p < 0.05) and volume water content (p < 0.1). However, soil nutrient and soil physical properties had no significant impact on aboveground biomass (p < 0.1). Compared with soil physical properties, soil nutrition is an important factor influencing the diversity index. In our study, the nonlinear responses of productivity and diversity of alpine meadow were described by using the multiple levels of degradation in space. The results suggested that aboveground productivity cannot interpret the degree of degradation of alpine meadow, and by contrast, alpine meadow degradation should be measured by the change of plant functional groups, such as edible grasses and poisonous forbs.

Key words: alpine meadow, degeneration gradients, species diversity, productivity, nonlinear response