应用LeBissonnais法研究黄土丘陵区植被类型对土壤团聚体稳定性的影响  

Application of le bissonnais method to study soil aggregate stability under different vegetaion on the loess plateau

作　　者：刘雷[1] 安韶山[1,2,3] 黄华伟[1] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100 [3]中国科学院水利部水土保持研究所,杨凌712100

出　　处：《生态学报》2013年第20期6670-6680,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金重点基金(41030532);国家自然科学基金面上项目(41171226);西北农林科技大学计划(QN2011049);新世纪优秀人才支持计划(NCET-12-0473)资助

摘　　要：植被类型直接影响土壤特性,对土壤团聚体的形成和稳定性有重要影响,水稳性团聚体是反映黄土高原土壤抗蚀性的最佳指标。选择黄土丘陵区延河流域作为研究区域,应用Le Bissonnais(LB)法和Yoder法测定了森林、森林草原两种植被类型下土壤水稳性团聚体稳定性,对比分析了LB法3种处理的结果,并计算土壤团聚体平均重量直径(mean weight diameter,MWD)和可蚀性因子K值。结果表明:在LB法3种湿润处理下,预湿后扰动处理(wet stirring,WS)对土壤团聚体结构的破坏程度最大,处理后土壤水稳性团聚体以<0.2 mm为主;快速湿润处理(fast wetting,FW)对团聚体的破坏程度次之;慢速湿润处理(slow wetting,SW)对团聚体的破坏程度最小,处理后土壤水稳性团聚体主要以>2 mm团聚体为主;说明黄土丘陵区延河流域土壤团聚体破坏的主要机制是气爆作用(消散作用)和机械扰动。LB法的3种处理结果中预湿后扰动的测定结果与传统的湿筛法(Yoder法)更接近。LB法包含Yoder法的基本原理,能够全面、准确的测定土壤团聚体结构,适宜作为黄土丘陵区土壤团聚体测定方法。森林植被类型的土壤团聚体平均重量直径大于森林草原植被类型,且SW>FW>WS,但可蚀性因子K值却是森林植被类型小于森林草原植被类型。土壤水稳性团聚体由小颗粒向大颗粒转变,土壤结构趋于稳定。不同植被类型下土壤有机质含量不同,土壤团聚体形成过程及土壤团聚度也有差异,因而造成土壤可蚀性和土壤抗蚀性能不同。The type of vegetation present in an area directly impacts soil characteristics and has a significant influence on the formation and stability of soil aggregates. Water-stable aggregates are the best indicator of soil stability and reflect the ability of a soil to resist erosion on the Loess Plateau of China. Soil samples were collected from both forest and forest steppe vegetation types in the Dong Zigou and Zhang Jiahe catchments, which are located in the Yanhe Catchment of the An Sai Hilly-Gully Region. This study investigated the characteristics of soil water-stable aggregate using the Le Bissonnais （LB） and Yoder methods ; the results of three LB treatments （ fast wetting （ FW）, slow wetting （ SW ）, and wetting stirring （WS）） were then compared and the mean weight diameter （MWD） of soil aggregates and erodibility factor （K） value werecalculated. The comparison of the three LB treatments showed ： 1 ） the WS treatment was the most destructive to the stability of soil aggregates and the soil water-stable aggregate particle size was mainly concentrated in the 〈0.2 mm size group; this illustrated that heavy rain and/or irrigation were the main factors destroying soil aggregates in the Loess hilly region; 2） the SW treatment was the least destructive to soil aggregate stability and soil water-stable aggregate particle size was mainly concentrated in the 〉2 mm size group; this shows that light rain or drip irrigation did not have strong damaging effects on soil aggregates; 3） the destructiveness of FW on soil aggregate structure was intermediate between that of the WS and SW treatments, indicating that the soil water-stable aggregate particle size was evenly distributed. The experiment shows that the primary destructive mechanism of soil aggregate structure in this region was dissipation and mechanical slaking. Aside from considering the impact of natural factors, one should use irrigation methods that cause minimal damage to soil aggregates as part of a larger effort to redu

关 键 词：土壤团聚体 LB法 Yoder法 黄土丘陵区 植被类型 

分 类 号：S154.4[农业科学—土壤学]