Journal of Resources and Ecology ›› 2019, Vol. 10 ›› Issue (5): 472-480.DOI: 10.5814/j.issn.1674-764X.2019.05.002

• Resources and Ecology in the Qinghai-Tibet Plateau • Previous Articles     Next Articles

Driving Mechanism of Gross Primary Production Changes and Implications for Grassland Management on the Tibetan Plateau

SUN Wei1, LI Meng1,2, WANG Junhao1,2, FU Gang1,*()   

  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 100049, China
  • Received:2019-04-15 Accepted:2019-06-20 Online:2019-09-30 Published:2019-10-11
  • Contact: FU Gang
  • Supported by:
    National Natural Science Foundation of China(31600432);National Key Research Projects of China(2017YFA0604801);National Key Research Projects of China(2016YFC0502005);Bingwei Outstanding Young Talents Program of Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences(2018RC202);Tibet Science and Technology Major Projects of the Pratacultural Industry(XZ201901NA03)

Abstract:

The contribution of climatic change and anthropogenic activities to vegetation productivity are not fully understood. In this study, we determined potential climate-driven gross primary production (GPPp) using a process-based terrestrial ecosystem model, and actual gross primary production (GPPa) using MODIS Approach in alpine grasslands on the Tibetan Plateau from 2000 to 2015. The GPPa was influenced by both climatic change and anthropogenic activities. Gross primary production caused by anthropogenic activities (GPPh) was calculated as the difference between GPPp and GPPa. Approximately 75.63% and 24.37% of the area percentages of GPPa showed increasing and decreasing trends, respectively. Climatic change and anthropogenic activities were dominant factors responsible for approximately 42.90% and 32.72% of the increasing area percentage of GPPa, respectively. In contrast, climatic change and anthropogenic activities were responsible for approximately 16.88% and 7.49% of the decreasing area percentages of GPPa, respectively. The absolute values of the change trends of GPPp and GPPh of meadows were greater than those of steppes. The GPPp change values were greater than those of GPPh at all elevations, whereas both GPPp and GPPh showed decreasing trends when elevations were greater than or equal to 5000 m, 4600 m and 4800 m in meadows, steppes and all grasslands, respectively. Climatic change had stronger effects on the GPPa changes when elevations were lower than 5000 m, 4600 m and 4800 m in meadows, steppes and all grasslands, respectively. In contrast, anthropogenic activities had stronger effects on the GPPa changes when elevations were greater than or equal to 5000 m, 4600 m and 4800 m in meadows, steppes and all grasslands, respectively. Therefore, the causes of actual gross primary production changes varied with elevations, regions and grassland types, and grassland classification management should be considered on the Tibetan Plateau.

Key words: alpine regions, elevation, grassland classification management, grassland types