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基于网格(20m×20m)采样法采集土壤样品,利用经典统计学和地统计方法分析了典型喀斯特峰丛洼地(200m×100m)土壤养分的空间变异特征.结果表明:研究区土壤pH值表现为弱变异,其他各养分指标均为中等程度变异,大小顺序为速效磷(AP)>速效钾(AK)>碱解氮(AN)>土壤有机质(SOM)>全钾(TK)>全磷(TP)>全氮(TN);pH半变异函数的最佳拟合模型为球状模型,TK和AK的最佳拟合模型为指数模型,其他养分指标的最佳拟合模型均为高斯模型;pH、AK的变异尺度(变程)较小,分别为58.1和41.1m,SOM、TN、TP、AN、AP的变异尺度相近,在100～150m,TK的变异尺度最大(463.5m);除研究区土壤TK、TN表现为中等的空间自相关性外,其他土壤养分指标均表现为强烈的空间自相关性.pH、AK呈零星斑块状分布,表现为高异质性;SOM、TP、TK的变化趋势较平缓,呈中间高、两边低的分布格局;AN、AP的空间分布具有显著的相似性,均随坡度的增加而呈片状上升趋势;TN的分布较特殊,呈中间低、两边高的趋势.植被、地形和高异质性的微生境是造成喀斯特木论自然保护区土壤养分格局差异的主要因素.
The soil samples were collected based on the grid (20m × 20m) sampling method and the spatial variability of soil nutrients in the typical karst peak-cluster depression (200m × 100m) was analyzed by using classical statistics and geostatistics methods. The results showed that the soil pH value (P> K)> AN> SOM> TK> total phosphorus (P <0.05) (TP)> total nitrogen (TN). The best fit model of pH semi-variogram was spherical model, the best fitted model of TK and AK was exponential model, and the best fitting models of other nutrient indicators were Gaussian model The variation scales of pH and AK are smaller, which are 58.1 and 41.1m, respectively. The variation scales of SOM, TN, TP, AN and AP are similar. The variation scale of TK is the largest (463.5m) at 100-150m. In addition to the medium spatial autocorrelation of soil TK and TN in the study area, other soil nutrient indicators showed strong spatial autocorrelation, with sporadic plaque-like distribution of pH and AK, showing high heterogeneity; SOM, The trends of TP and TK are relatively flat, with a middle high and a low distribution on both sides. The spatial distribution of AN and AP has significant similarities with The distribution of TN is rather special, showing the middle low, high on both sides.The vegetation, topography and high heterogeneity of micro-habitat are the main factors that cause the difference of soil nutrient pattern in Karst woods nature reserve factor.