澜沧县尾叶桉类林土壤养分空间分布特征探讨

应用地统计学方法及GIS空间分析技术,探讨了澜沧县尾叶桉类林林下土壤的全碳、全氮、全磷、全钾、有效钙和有效镁6种养分的空间分布特征.结果表明:全碳和全氮之间存在显著的正相关性,相关系数高达0.878;有效钙和有效镁之间的相关系数为0.621.全钾的变异系数为0.35,有效钙的变异系数为0.89.在空间上,全碳、全磷、全钾、有效钙和有效镁5种养分的块金值(Nugget)与基台值(Sill)的比值均小于25%;全氮的块金值与基台值的比值为32.32%.采用普通克里格插值方法对6种养分的空间分布进行插值计算分析,结果显示:全碳和全氮在空间分布上存在一定程度的相似性,含量自北向南逐渐降低;全磷含量自西北向东南呈"鞍形"分布,西北和东南较高,中间部分相对较低,且是整体分布较破碎;全钾含量分布相对均匀,大部分区域含量为2 457.94～3 018.63μg/g;有效钙分布主要集中在西北、南部和东部,其他区域相对较低;有效镁含量东部最高,整体上从东南向西北呈递减趋势.

Study on Spatial Distribution of Soil Nutrients in Com.Eucalyptus urophylla in Lancang County

The spatial distribution of soil total carbon(TC),total nitrogen(TN),total phosphorus(TP),total potassium(TK),available calcium(ACa) and available magnesium(AMg) is studied with geo-statistics method and GIS spatial analysis tools in the Eucalyptus urophylla-planting regions of Lancang county.The results are outlined as follows.TC and TN are in a significant positive correlation,r being 0.878.The correlation coefficient between ACa and AMg is 0.621.The CV(coefficnet of variance) of TK and ACa is 0.35 and 0.89,respectively.Ordinary Kriging interpolation results show that TC and TN are similar in spatial distribution,their contents being higher in the northern part of the county.TP presents a fragmentized saddle-shaped distribution with higher content in the northwest and southeast and lower content in the center area.The spatial distribution of TK is relatively even,varying from 2 457.94 to 3 018.63 μg/g.ACa is mainly distributed in the northwestern corner,the southern corner and the eastern corner.The eastern part of the county has the highest AMg content,which decreases gradually from the southeastern to the northwestern part.