六盘山华北落叶松林坡面土壤密度空间变异与合理取样数  

Spatial Heterogeneity and Reasonable Sample Sizes of Soil Bulk Density on A Larch Plantation Hillslope in Liupan Mountains

作　　者：邓佳楠 刘帆 刘泽彬[2] 郭建斌[1] 王彦辉[2] DENG Jia-nan;LIU Fan;LIU Ze-bin;GUO Jian-bin;WANG Yan-hui(College of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Ecology and Nature Conservation Institute,Chinese Academy of Forestry/Key Laboratory of Forestry Ecology and Environment of National Forestry and Grassland Administration,Beijing 100091,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]中国林业科学研究院森林生态环境与自然保护研究所/国家林业和草原局森林生态环境重点实验室,北京100091

出　　处：《林业科学研究》2022年第4期162-169,共8页Forest Research

基　　金：中国林业科学研究院基本科研业务费专项资金项目(CAFYBB2020QB004;CAFYBB2021ZW002);国家自然科学基金项目(41971038;U20A2085)。

摘　　要：[目的]明确森林坡面土壤密度的空间异质性并量化其合理取样数,对于准确理解坡面产流变化机制具有重要意义。[方法]结合传统统计学和地统计学方法,分析了六盘山华北落叶松林坡面0~100 cm土层土壤密度的空间异质性,用Monte Carlo模拟重抽样的方法,量化95%置信区间、10%误差下土壤密度的最少取样数。[结果]华北落叶松林坡面100 cm土层土壤密度变化范围0.99~1.48 g·cm^(−3);随土层加深,土壤密度逐渐增加。传统统计学表明,0~20 cm土层土壤密度属弱变异,其它土层均为中等变异,石砾含量的空间异质性是导致坡面不同土层土壤密度空间变异的主要因素。地统计学表明,各层土壤密度空间结构均为中等空间自相关性。不同土层土壤密度空间变异程度的不同导致其最少取样数存有明显差异,在95%的置信区间,若要控制坡面100 cm土层土壤密度评估精度在10%误差内,至少需布设10个以上的取样点。[结论]森林坡面土壤密度存有较大空间变异,且其合理取样数的大小取决于空间变异程度,未来应基于土壤密度空间变异程度与合理取样数的关系制定合理、高效的取样策略。[Objective]Clarifying the spatial heterogeneity of soil bulk density on forest slopes and quantifying its reasonable sample sizes are of great significance for accurately understanding the runoff mechanism on hillslopes.[Method]Combining traditional statistics and geostatistics methods,the spatial heterogeneity of soil bulk density in 0~100 cm soil layer on a Larix gmelinii var.principis-rupprechtii(Mayr)Pilg.plantation hillslope in Liupan Mountains was analyzed.The minimum sampling sizes of soil bulk density under 95%confidence level and 10%error were quantified using Monte Carlo simulation sampling method.[Result]The soil bulk density in 100 cm soil depth on the hillslope varied from 0.99~1.48 g·cm^(−3).As the soil layer deepened,the soil bulk density gradually increased.Traditional statistics showed that the soil bulk density in 0~20 cm soil layer had weak variation,while other soil layers had moderate variation.The spatial heterogeneity of rock fragment on the slope was the main factor leading to the spatial variation of soil bulk density in different soil layers.Geostatistics showed that the spatial structure of soil bulk density in each soil layer was moderate spatial autocorrelation.The difference in the spatial variation of soil bulk density among different soil depths leaded to the differences in the minimum sampling size in varied soil depths.In the 95%confidence interval,if estimation accuracy of the soil bulk density in 100 cm soil layer was controlled to be within 10%error,at least 10 sampling points should be made.[Conclusion]There is a large spatial variation in soil bulk density on forest hillslope,and the reasonable sample size depends on the degree of spatial variation in soil bulk density.In the future,reasonable and efficient sampling strategies should be developed based on the relationship between the spatial variation of soil bulk density and the reasonable sampling sizes.

关 键 词：华北落叶松林坡面 土壤密度 空间异质性 合理取样数 

分 类 号：S714.2[农业科学—林学]