岩溶石漠化山地不同退耕模式土壤抗蚀性及其与结构体分形关系研究  

Study on erosion resistance of soil and fractal features of soil aggregates under different patterns of farmland set-aside in karst rock desertification area

作　　者：胡宁[1] 傅瓦利[1] 马志敏[1] 甄晓君[1] 袁红[1] 

机构地区：[1]西南大学地理科学学院,重庆北碚400715

出　　处：《中国岩溶》2008年第2期115-121,共7页Carsologica Sinica

基　　金：科技部攻关项目"重庆地区喀斯特山地退化生态系统恢复与重建技术开发"(编号:2006BAC01A16)

摘　　要：通过对岩溶石漠化山地中小尺度范围内的现有三种主要退耕模式及对照地土壤抗蚀性主成分分析及与各级结构体分形维数关系研究，结果表明：（1）研究区退耕地在3～6年内土壤抗蚀性均发生了比较明显的变化，但都介于传统耕地与马尾松次生灌丛之间，其中以具有复式结构的退耕樟树＋草被退耕模式的抗蚀效果较理想；（2）与传统旱耕地不同，各退耕模式土壤抗蚀性均是A层土壤强于B层土壤，表明退耕有利于A层土壤抗蚀性迅速提高，尤其是草本＋乔灌模式对A层土壤抗蚀性的提高更为显著；（3）〉O．25mm水稳性团聚体含量及破坏率、水稳性指数、有机质含量为评价土壤抗蚀性的最佳四指标；（4）微团聚体、风干团聚体分形维数表征土壤抗蚀性有一定的局限性，而机械组成、水稳定性团聚体分维数与抗蚀性综合分值相关性较高，尤其是水稳性团聚体分形维数可较好地反映出土壤的抗蚀特性。Research on correlation between erosion resistance of soil and the fractal features of soil aggregate under three different patterns of farmland set-aside at small scope in karst rock desertification area indicate that： （1） Erosion resistance of soil changes obvious after 3 to 6 years set-aside, but erosion resistance of soil after set-aside range from traditional farmland to Pinus massoniana forest land. Among the three kinds of set-aside pattern, the erosion resistance of soil is highest under Cinnamomum camphora ＋ grass. （2） Different from traditional farmland , at set-aside farmland, the erosion resistance of soil in horizon A are higher than horizon B, which shows that set-aside can improve erosion resistance of soil in horizon A faster, espe- cially under the camphor tree ＋ grass pattern. （3）〉0. 25mm water-stable aggregates and destructive rate （including 〉0. 5mm water-stable aggregates and destructive rate）, water-stable index, content of organic matter, are optimal indexes to appraise erosion resistance of soil. （4） Correlation analysis indicates that the fractal dimensions of micro-aggregates and dry-aggregates are not able to express erosion resistance of soil ideally, but the fractal dimensions of mechanical composition and water-stable aggregates can express ideally, especially the fractal dimensions of water-stable aggregates.

关 键 词：退耕模式 土壤抗蚀性 主成分分析 结构体分形 岩溶区 

分 类 号：S157[农业科学—土壤学]