RESEARCHES ON THE SPATIO-TEMPORAL VARIATION OF CARBON CONSUMPTION BY AGRICULTURAL AND FORESTRY UTILIZATION IN CHINESE TERRESTRIAL ECOSYSTEMS DURING 2000s
Human, an important component in terrestrial ecosystems, can be regarded as the consumer of terrestrial ecosystems. Utilization of net primary productivity ( NPP ) by human is an important route for the regional carbon consumption. Quantifying the characteristics of carbon consumption induced by agricultural and forestry utilization is helpful to assess the net carbon exchange between the biosphere and the atmosphere,which would provide the theoretical basis for carbon management of terrestrial ecosystems. Based on the statistical data of agricultural products, grassland products and forest products, we evaluated the spatial and temporal variation of the carbon consumption by agricultural and forestry utilization, including their annual total amounts and their magnitudes, in Chinese terrestrial ecosystems during 2000s. Results indicate that the annual total amount of the carbon consumption by agricultural and forestry utilization was 805. 79TgC/a from 2001 to 2010, accounting for 28. 49% of the total annual NPP, with the maximum values appearing in Shandong, Henan and Guangxi provinces. Among the annual total amount of carbon consumption, that caused by agricultural products utilization was 630. 54TgC/a, with the maximum values also appearing in Shandong, Henan and Guangxi provinces, while that caused by grassland products utilization was 114. 90TgC/a, with the largest contributions from Inner Mongolia, Xinjiang and Sichuan, but that induced by forest products utilization was only 60. 35TgC/a, mainly locating in Fujian, Zhejiang and Hunan provinces. The magnitude of the carbon consumption by agricultural and forestry utilization resulted from different sources differed in their spatial variations. The highest magnitude of the carbon consumption by agricultural and forestry utilization appeared in Shandong and Jiangsu provinces, which was similar to that caused by the agricultural products utilization, while that caused by grassland products utilization occurred in Chongqing, Inner Mongolia and Sichuan provinces, but that induced by forest products utilization occurred in Zhejiang and Fujian provinces. The annual total amounts of carbon consumption increased obviously during the examining period,with an increasing rate of 22.02TgC/a, which was comparable with its magnitude. This study indicate that carbon consumption induced by agricultural and forestry utilization plays an important role in maintaining the regional carbon balance of terrestrial ecosystems, which should be paid more attention in future.