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为研究喀斯特峰丛洼地小流域土壤化学性质的空间变异性,基于规则网格取样(80m×80m),测定了典型喀斯特峰丛洼地木连喀斯特小流域163个表层(0cm~20cm)土壤样点基本养分全氮TN(total nitrogen)、全磷TP(total phosphorus)、全钾TK(totalpotassium)、有效氮AN(available nitrogen)、速效磷AP(available phosphorus)、速效钾AK(available potassium)、有机质SOM(soilorganic matter)含量和pH值,并利用经典统计学和地统计方法进行了空间变异特征分析。结果表明:研究区土壤这8种指标数值的差异及变异系数均较大,各项土壤养分指标的变异程度依次为TK>AP>AN>TN>SOM>AK>TP>pH。不同养分指标具有不同的空间结构和最佳拟合模型,除TK和pH呈现强烈空间自相关、变程较短、空间依赖性较强外,其余6种指标(TN、TP、AN、AP、AK、SOM)均呈中等空间自相关,变程较长,空间连续性较好。Kriging等值线图直观、清晰的反映了研究区土壤养分空间格局。TN、AN、SOM的Kriging等值线图相似并且它们的空间分布趋势与pH正好相反,TP和AP的Kriging等值线图相似,TK和AK的Kriging等值线图相似。除pH外,木连喀斯特小流域养分空间格局可概括为:东边高,西边低,南边高,北边低,洼地高,坡地低。人为干扰和自然条件(地形、地貌、植被、裸岩率、坡度、坡向)是土壤养分空间异质性的主要影响因素。
In order to study the spatial variability of soil chemical properties in a karst cluster-cluster depression basin, based on a regular grid sampling (80m × 80m), soil samples from 163 surface layers (0cm ~ 20cm) in a Karst small Karst peak cluster depression Total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, and organic matter SOM (soilorganic matter) content and pH, and analyzed the characteristics of spatial variability by using classical statistics and geostatistical methods. The results showed that the differences of the eight indexes and their coefficients of variation in the soils in the study area were relatively large. The variation degree of soil nutrients in order of TK> AP> AN> TN> SOM> AK> TP> pH, respectively. Different nutrient indicators had different spatial structures and best fitting models except that TK and pH showed strong spatial autocorrelation, short variation range and strong spatial dependence. The other six indicators (TN, TP, AN, AP, AK, SOM) showed medium spatial autocorrelation, longer change range and better spatial continuity. The Kriging contour plots intuitively and clearly reflect the spatial pattern of soil nutrients in the study area. The Kriging contour plots of TN, AN and SOM are similar and their spatial distribution trend is opposite to that of pH. The Kriging contour plots of TP and AP are similar, and the Kriging contour plots of TK and AK are similar. In addition to pH, the nutrient spatial pattern of the Klinster catchment can be summarized as follows: high in the east, low in the west, high in the south, low in the north, high in the depression and low in the slope. Human disturbance and natural conditions (topography, physiognomy, vegetation, bare rock rate, slope, aspect) are the main factors affecting the spatial heterogeneity of soil nutrients.