Effects of climate change on primary production in the Inner Mongolia Plateau, China

摘要

Climate change has significant effects on primary productivity and ecosystem function. To assess these effects in the Inner Mongolia Plateau of China, we analysed the 8 km normalized difference vegetation index (NDVI) time-series from the Global Inventory Monitoring and Modeling System (GIMMS) data set and characterized vegetation productivity between 1981 and 2011. We used canonical correspondence analysis (CCA) to elucidate the relationship between productivity and climatic factors for different vegetation types and model the response of productivity to climate change. We found the following. (1) Productivity in the study area exhibits high spatial heterogeneity while generally decreasing from northeast to southwest, which is mainly driven by precipitation patterns. (2) Most of the total variation (88.35%) of NDVI can be explained by precipitation and temperature. Around 46.19% of the total variation is explained solely by precipitation, 31.85% by temperature, and 10.31% by the precipitation and temperature interaction term. (3) Productivity of most ecosystems of the area increased gradually between 1981 and 2011. The central region of the Plateau is characterized by the high annual coefficient of variation (CV) of NDVI, which is mainly attributable to the desert steppe, the most sensitive ecosystem of the area. (4) Climate factors influence primary productivity differently in different vegetation zones of our study area. Primary productivity of forest and agricultural areas is explained mainly by temperature and steppe vegetation by precipitation. Desert vegetation is closely related to both precipitation and temperature. Not only did the study quantitatively assess the effects of climate changes on primary production, but it also provided an important basis for a comprehensive analysis of climate change on ecosystem function in the Inner Mongolia Plateau.