Recent responses of grassland net primary productivity to climatic and anthropogenic factors in Kyrgyzstan
[2020]
Authors
Wang, Y., Yue, H., Peng, Q., He, C., Hong, S. and Bryan, B.A.
Article Summary
Net primary productivity (NPP) is an essential indicator of ecosystem function and sustainability and plays a vital role in the carbon cycle, especially in arid and semiarid grassland ecosystems. Quantifying trends in NPP and identifying the contributing factors are important for understanding the relative impacts of climate change and human activities on grassland degradation. For our case‐study of Kyrgyzstan, we quantified from 2000 to 2014 the spatial and temporal patterns in climate‐driven potential NPP (NPPP) using the Zhou Guangsheng model specifically developed for Asian grasslands, and actual NPP (NPPA) using the globally calibrated MOD17A3 NPP data product. By calculating the difference between NPPP and NPPA, we inferred human‐induced NPP (NPPH) and thereby characterized changes in grassland NPP attributable to anthropogenic activities. The results showed that grassland NPPA in Kyrgyzstan experienced a slight decrease over time at an average rate of −0.87 g C·m−2·yr−1 but patterns varied between provinces. Nearly 60% of Kyrgyzstan's grasslands experienced degradation mostly in the northern parts of the country, while grassland NPPA increased over more than 40% of the study area, occurring mostly in the south. Climate change, in particular change in precipitation was the dominant factor driving grassland degradation in the north but human pressures also contributed. In the south, however, human activities were associated with extensive areas of grassland recovery. The results provide important contextual understanding for supporting policy for grassland conservation and restoration under future climate change and intensifying human pressures.
