三峡库区植物篱系统土壤颗粒分形特征及其与土壤理化性质的关系

Soil Particle-Size Fractal Characteristics and the Relationship with Physicochemical Properties of Soil in Hedgerow Systems in the Three Gorges Reservoir Area

在对长江三峡库区坡耕地植物篱系统调查样地土壤样品颗粒分析的基础上,对植物篱系统内土壤颗粒分布及土壤分形维数与土壤物理性质和土壤养分含量的关系进行了研究,结果表明:(1)乔木类、草本类和灌木类植物篱带间坡耕地土壤砂粒含量比其对应的植物篱带内土壤沙砾平均含量分别高10.4%,13.7%和9.2%;而黏粒含量在植物篱带内富集,其平均含量比植物篱带间坡耕地土壤黏粒含量分别高14.3%,19.5%和10.7%;(2)土壤分形维数与土壤黏粒和土壤粉粒含量具有显著(P<0.01)的正相关关系,而与土壤砂粒含量显著负相关。(3)土壤分形维数与土壤孔隙度、含水量和土壤饱和导水率极显著正相关,而土壤容重与分形维数呈显著负相关关系。土壤分形维数与土壤有机质、土壤全氮、土壤有效氮、土壤全钾、土壤有效钾、土壤全磷含量和阳离子交换量显著相关,而土壤有效磷含量和土壤分形维数相关性不显著。

To achieve well understanding of soil particle-size fractal characteristics and the volume fractal dimension（Dv） variance among hedgerow agroforestry system, and also the correlations between Dv and soil physical properties and nutrients, soils sampled from inventory plots located in the Three Gorges Reservoir area of the Yangtze River were analyzed in this study. Dv was calculated and the relations between Dv and soil physicochemical properties were tested. The result indicated that. （1） sand concentrations of soil under hedgerows stripe were reduced by 14.3 %, 19.5 % and 10.7 % respectively compared with those of soils taken from between hedgerows, the clay concentrations of soils under hedgerows stripe increased under hedgerow with the increment of 14.30 %, 19.5 % and 10.7 %; （2） Dv was correlated positively and highly significantly （P〈0.01） with the soil clay concentration and less significantly （P〈0.05） with soil silt content, however, Dv was negatively correlated with soil sand concentration; （3） Dv of soil in hedgerow systems was correlated positively and highly significantly （P〈0. 01） with the soil porosity, water content, soil saturated water con- ductivity, and correlated negatively with soil bulk density. In addition, the Dv of soils in hedgerow systems were highly positively correlated with total and available nitrogen, total and exchangeable potassium, total phosphorus and cation exchangeable capacity.