Abstract:

Net primary productivity (NPP) is one of the most important indicators of terrestrial ecosystem carbon cycle, and is also the material basis for the survival and development of human society. Therefore it plays an important role in the global environment change and the development and utilization of natural resources. Based on the simulated NPP data from GLOPEM-CEVSA model, air temperature, precipitation and sunshine hours data from 2043 weather stations as well as El Ni?o/La Ni?a events from 1982 to 2011, the spatial and temporal distributions and dynamic changes of NPP in terrestrial ecosystem were analyzed, and the relationships between NPP and climatic factors and ENSO events in China were examined using the GIS spatial analysis and mathematical statistics methods. Results indicated that vegetation NPP increased at a rate of 5.66 gCm^-2 per decade in China during 1982-2011, especially in the 1980s it increased significantly at a linear rate of 50.0 gCm^-2 per decade. Spatially, vegetation NPP increased in western China and the northern and eastern parts of Northeast China, whereas it decreased in the central part of Northeast China, North China Plain, the mid-eastern part of Inner Mongolia, the Yangtze River Delta and the Pearl River Delta in the past 30 years. In the Yangtze-Huaihe river basins, the decrease of vegetation NPP and the reduction of sunshine hours had good corresponding relationships, and in northern China and northern Xinjiang, the increase (decrease) of NPP was relied more on the increase (decrease) of precipitation. In Northeast China, the increase of NPP was associated with the increases in sunshine hours and temperature. For China as a whole, in El Ni?o years, regions with the increase of vegetation NPP were slightly larger than those of NPP decrease, but in La Ni?a years regions with the increase of vegetation NPP was basically equal to those of NPP decrease, and sunshine hours was the main climate factor which leads to the differences of vegetation NPP between El Ni?o years and La Ni?a years. More attentions should be paid to the impacts of radiation, extreme climatic events and anthropogenic air pollution on vegetation NPP in different regions of China in future.

Key words: net primary productivity, spatial-temporal evolution, climatic impacts, El Ni?o/La Ni?a events, China