扬子江城市群土地利用时空变化及其对陆地生态系统碳储量的影响

扬子江城市群是江苏省城市化进程最快,土地利用变化最明显的区域。研究该地区地利用变化及其对陆地生态系统有机碳储量的影响,对江苏省低碳土地利用研究具有重要意义。该文利用五期30 m土地利用栅格数据、土壤样点数据、林地植被清查数据、农作物数据以及经验数据,分析了1995～2015年扬子江城市群土地利用时空变化、核算了其对有机碳储量的影响。主要结果如下:(1) 1995～2015年间,扬子江城市群约有15. 90%的土地发生了转移,其中,耕地作为主要的转出者,建设用地作为主要的转入者,耕地转移为建设用地的面积约为4 161. 78 km~2,占扬子江城市群耕地转出面积的85. 86%,是主要的土地转移类型;(2) 1995～2015年间,由于土地利用类型转移变化,扬子江城市群有机碳储量总量减少了472. 63×10~4t,其中土壤有机碳储量总量增加110. 28×10~4t,植被碳储量总量减少582. 91×10~4t;(3)建设用地占用耕地是区域有机碳储量减少的主要原因,导致有机碳储量减少406. 40×10~4t,占整个区域有机碳储量减少总量的85. 99%;(4)未来扬子江城市群可通过增加生态用地、控制建设用地、优化土地利用结构,提高区域碳储量,减少对陆地生态系统碳平衡的扰动。

Spatio-temporal Analysis of Land-Use Change and the Impact on Terrestrial Ecosystems Carbon Storage in Yangtze River City Group

The Yangtze River City Group is under the fastest urbanization process in Jiangsu, which caused the most obvious land use change. Study of land use change and its impact on carbon storage of terrestrial ecosystems in the Yangtze River City Group is of great significance to the study of low-carbon land use in Jiangsu Province. Based on the five-phase 30m land use raster data, soil sample data, forest vegetation inventory data, crop data and empirical data, this research assessed the spatio-temporal change of land use and its impact on carbon storage from 1995 to 2015. The main results were as follows: (1) from 1995 to 2015, about 15.90% of the land area hadtheir land use type changed. Among them, built-up land occupy cultivate land was the main land transfer type, with total transferred area reached to 4 161.78 km2, accounting for 85.86% of the total transferred out of cultivated land; (2) due to the land use changes, total carbon storage decreased by 472.63×104 t, of which soil organic carbon increased by 110.28×104 t, and the vegetation carbon decreased by 582.91×104 t; (3) the transfer of cultivated land to built-up land was the main determinant for the loss of carbon storage, with amount of 406.40×104 t, and accounted for 85.99% of the total carbon storage loss; (4) in the future, by means of increasing ecological land area, controlling built-up land, and optimizing land use structure, the Yangtze River City Group can reduce the disturbance to terrestrial ecosystem carbon balance and increase regional carbon storage.