经济发达区土地利用变化对土壤氮含量的影响——以江苏省原锡山市为例

Effects of land use changes on N element in the developed areas—A case of former Xishan city of Jiangsu Province

选取经济发达区原锡山市作为研究区域,以土壤全氮和速效氮作为研究对象,探讨土地利用变化对土壤氮含量的影响,以表明人类活动对生态系统的影响。结果表明,20年来原锡山市土壤全氮含量降低0.16 g.kg-1,速效氮含量降低7.63 mg.kg-1;通过变异函数分析表明,20年来原锡山市全氮和速效氮的变异函数理论模型都是指数型,但块金方差与基台值的比值、自相关阀值发生了较大变化;Kriging插值分析结果表明,1982年全氮和速效氮的分布比较简单,2005年全氮分布较为复杂,速效氮分布较为简单。

Land use change may influence a variety of natural and ecological processes,including soil nutrient, soil moisture, soil erosion, land productivity and biodiversity. Through application of Geo-statistics combined with GIS, the spatio-temporal variability of N element in former Xishan city between 1982 and 2005 was analyzed. Independent geostatistics shows that all nitrogen decreased 0. 16 g·kg^-1, available nitrogen decreased 7.63 mg·kg^-1 ; semivariogram modeling indicates that the model for all nitrogen and available nitrogen in former Xishan city remain unchanged,however the ratio of Nugget/Sill and the correlation threshold changed significantly ; the result of Kriging Interpolation indicates that, in both 1982 and 2005 ,the spatial pattern of available nitrogen are simple ,but the patterns changed significantly. The spatial patterns of all nitrogen and available nitrogen were simple in 1982 ,but that of all nitrogen became rather complex in 2005.