区域稻田土壤碳储量的空间分布特征

深受利用方式影响的农业土壤碳库在缓减大气二氧化碳浓度增加和温室效应加剧方面具有十分重要的作用.为了明确区域稻田土壤碳库蓄积量及其空间分布特征,以全国第二次土壤普查数据资料为基础,运用地理信息系统软件Arcview建立研究区以土种为单位的空间数据库,结合GIS空间分析功能,基于土壤类型法估算重庆市巴南区稻田土壤有机碳储量及其空间分布特征,结果表明:研究区稻田土壤有机碳总储量约为6.48×106t,平均土壤有机碳密度为8.31 kg/m2,略高于全国平均水平.重庆市巴南区稻田0～20 cm土壤有机碳密度介于1.73～3.70 kg/m2之间,剖面土壤有机碳密度介于5.13～14.07 kg/m2之间.0～20 cm和100 cm土壤有机碳储量分别为1.18×106 t和4.39x106t,0～20 cm土壤有机碳储量为0～100 cm碳储量的27.50%,说明碳储量主要富集在表层土壤.土壤有机碳密度呈带状分布,且具有高度的不均匀性,同类土壤具有相似的有机碳蓄积量.

Distribution of Organic Carbon Storages in Purple Paddy Field Basined on Region Scale

Basined on soil type methods and region scale, the distribution of soil organic carbon storages in purple paddy soil of Chongqing were investigated. The results showed that the storage of SOC in Banan district of Chongqing was 6.48×106 t and average SOC density in Banan district with 8.31 kg m-2 was higher than that of China. Carbon density of paddy soil in Banan district ranged from 1.73 kg m-2 to 3.70 kg m-2 at the depth of 0-20 cm, while that in profile ranged from 5.13 kg m-2 to 14.07 kg m-2. Storages of SOC at the depth of 0-20 cm and at the depth of 100 cm were 1.18×106t and 4.39×106 t, respectively. The whole distribution trend of SOC density with strip was high heterogeneous characters and the similar accumulation of SOC storages was observed among the same type of soils.