Spatiotemporal-Distribution Pattern Variation of Net Primary Productivity in Potential Natural Vegetation and Its Response to Climate and Topography in China
As one system possessing the ability to classify global potential natural vegetation types,Comprehensive and Sequential Classification System (CSCS)has important guiding significance in development and management of animal husbandry and macroscopical cognition of pastoral agriculture.In this study, we tried to simulate Net Primary Productivity(NPP)of potential natural vegetation and its spatio-temporal distribution pattern,and the response to climate and topography in China using meteorological data and the improved CASA model(Carnegie Ames Stanford Approach)in conjunction with NDVI(Normalized Difference Vegetation Index)time series datasets during 1982-2012.Research results showed that NPP of potential natural vegetation in China represented an increase trend following the times series from 1982 to 2012.Significant heterogeneity was embodied on its spatial distribution pattern for NPP of potential natural vegetation.NPP of each CSCS types and super-types were different.High agreement of spatio-temporal variation was achieved between NPP of potential natural vegetation and temperature,precipitation and solar radiation in China.NPP of potential natural vegetation reflected increase,decrease and increase trend with the increase of elevation,slope and aspect,respectively.NPP of each CSCS types generally performed the horizontal and vertical zonal distribution pattern of water and heat for natural vegetation,which had homoplasy with index chart of CSCS.The study results could promote the amalgamation of research in CSCS and global change fields.