基于GIS的土壤有机碳储量核算及其对土地利用变化的响应

土地利用变化是影响土壤有机碳储量变化的重要驱动因素，为了进一步探讨土地利用变化对土壤碳储量的影响，该文根据土壤样点数据、土壤类型图、土地利用类型图，分析了江苏省1985年和2005年表层土壤有机碳密度的变化以及土地利用变化对表层土壤有机碳密度的影响，主要结论如下：1）江苏省表层土壤有机密度的空间变化趋势为：黄淮平原生态区南北差异明显，北部的沂沭泗平原丘岗以增加为主，南部的淮河下游平原以减少为主；沿海滩涂与海洋生态区持平为主；而长江三角洲平原生态区表现不一：沿江平原丘岗生态亚区以增加为主，而茅山宜溧低山丘陵生态亚区和太湖水网生态亚区均表现为有机碳密度的减少；2）各地类表层土壤有机碳密度均有所增加；耕地-林地、草地；草地-林地、建设用地；建设用地-耕地、草地、林地；水域的转出以及未利用地的转出等转换类型有利于土壤碳储量的增加、其他地类间的转换会造成一定的碳排放。

Accounting of surface soil carbon storage and response to land use change based on GIS

Land use change is a main driving factor to the change of soil organic carbon (SOC) storage, in order to make a further study about the effects of land use change on SOC, based on the soil sampling data, soil type map and land use map of Jiangsu, this paper analyzed the spatial changes of the surface SOC density from 1985 to 2005 in Jiangsu and the effects of land use change on surface SOC density and SOC storage, the main conclusions are as follows: 1) The spatial changing trend of the surface SOC storage from 1985 to 2005: The changing trend in Huanghuai plain district differed too much from north to south, the Northern Yimusi plain mainly increased, while the lower reaches of Huaihe plain decreased mostly in the South; The changes in coastal beaches and ocean districts were not obvious; There presented greatly differences in Yangtze river delta plain district about SOC changes: districts covered with plain and hill along Yangtze river mainly increased, but in the Maoshanyisu hills and Taihu lake districts it both decreased. 2)The surface SOC density of different land uses all increased from 1985 to 2005, land use changes such as from cropland to woodland and grassland; grassland to woodland and construction land; construction land to cropland, woodland, grassland; wetland, construction land to other land uses can increase SOC storage, while other type of land use changes may lead to carbon emission.