上海城市样带土壤有机碳空间变异性研究

RESEARCH ON SPATIAL VARIABILITY OF SOIL ORGANIC CARBON CONTENT IN THE URBAN-TRANSECT OF SHANGHAI

为揭示城市化、工业化等人为活动对土壤有机碳的影响,选择能反映上海城郊乡梯度差异的城市样带,采用地统计学方法对表层土壤样品土壤有机碳的空间变异结构和分布格局进行了分析。结果表明:城市表层土壤有机碳含量均属中等变异,徐汇区土壤有机碳含量呈正态分布,奉贤区、闵行区和所研究样带土壤有机碳含量呈对数正态分布。半方差函数模型拟合结果显示徐汇和闵行区土壤有机碳符合指数模型,奉贤和所研究样带土壤有机碳符合球状模型。通过泛克里格插值得到城市表层土壤有机碳含量空间分布图,发现徐汇、闵行区土壤有机碳呈岛状,奉贤区呈条带状,而所研究样带呈条带和岛状分布相结合的特点。土壤有机碳含量城郊乡梯度差异明显,工业化、城市化、肥料投入与管理等人为因素对城市土壤有机碳空间分布密切相关。

Soil organic carbon（SOC） content along the typical urban-transect in Shanghai were analyzed to indicate the effect of urbanization and industrialization on soil quality.Spatial variation structure and distributions of soil organic carbon content in the topsoil in the urban-transect were analyzed.The results showed that soil organic carbon content in topsoil were medium in variability,SOC in Xuhui district was distributed normally,while SOC in Minhang,Fengxian and the selected urban-transect were distributed lognormally.The results of semivariance analysis showed that SOC in Xuhui and Minhang districts were fit for the exponential model,SOC in Fengxian district and the selected urban-transect were fit for the spherical model.The spatial distribution maps of SOC content of the topsoil in this city-transect were produced by means of the universal Kriging interpolation.SOC in Xuhui and Minhang districts was spatially distributed in island,SOC in Fengxian district were distributed in ribbon,while the spatial distribution of SOC in the selected urban-transect showed the mixed characteristic of ribbon and island.Difference of soil organic carbon along ＂Urban-suburban-rural＂ was obviously.The special variation of SOC content in the topsoil were closely related to the industrialization,urbanization,application of fertilizer and agricultural management of the city.