【摘要】 为揭示岩溶山地生态退化的海拔空间变异,应用地统计学对地处滇黔桂连片岩溶腹地,海拔变化范围广的贵州省毕节地区生态退化指标的垂直梯度空间变异进行分析。石化率的半变异函数最佳理论模型为线性有基台模型,植被覆盖率、土壤砾石率为球状模型。植被覆盖率的空间异质比为22.32%,具有强烈的垂直梯度空间相关性,主要受到随海拔梯度变化的自然性控制因素的作用;石化率、土壤砾石率的空间异质比分别为34.38%、25.97%,均具有中等程度的垂直梯度空间相关性,受随机因素的作用较大。土壤砾石率、植被覆盖率的变程分别为968.10、859.48m,受因素影响的海拔范围都较宽;石化率的变程为52.28m,受因素影响的海拔范围很窄。石化率、植被覆盖率的Moran′sⅠ系数随海拔梯度变化的趋势相类似,但土壤砾石率的Moran′sⅠ系数随海拔梯度变化的趋势与石化率、植被覆盖率的差别较大。更多还原

【Abstract】 To reveal altitudinal spatial variability of ecological degeneration in Bijie Prefecture,Guizhou Province,vertical gradient of ecological degeneration indexes were analyzed using geostatistics.The study site is in the centre of Yunnan,Guizhou,Guangxi Karst area where the altitudinal variation ranges widely.The optimal semivariogram theoretical model of bedrock exposure rate was linear with a sill model;the vegetation cover and soil gravel rates were a spherical model.The spatial relativity of vegetation cover was strong with vertical gradient and it was mainly affected by natural control factors with altitudinal variation.The rate of nugget to sill was 22.32%.The spatial relativity of bedrock exposure and soil gravel rate were moderate with vertical gradient and they were mainly affected by random factors.The rate of nugget to sill were 34.38% and 25.97%.The ranges of soil gravel rate and vegetation cover were 968.10 and 859.48 m.These data showed that soil gravel rate and vegetation cover were affected by wide altitudinal ranges.The range of bedrock exposure was 52.28 m indicating that it is affected by narrow ranges.Moran’s I for bedrock exposure and vegetation showed similar trends along altitudinal gradient;however,that for soil gravel rate was quite different.更多还原