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

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 应用Le Bissonnais 法研究黄土丘陵区植被类型对土壤团聚体稳定性的影响 DOI: 10.5846/stxb201301160103 作者: 作者单位: 西北农林科技大学 资源环境学院,西北农林科技大学 资源环境学院,中国科学院水利部水土保持研究所,,西北农林科技大学 资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 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 Application of le bissonnais method to study soil aggregate stability under different vegetaion on the loess plateau Author: Affiliation: College of Resources and Environmental Sciences,Northwest A F University,College of Resources and Environmental Sciences,Northwest A F University,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,College of Resources and Environmental Sciences,Northwest A F University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 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。 Abstract: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 were calculated. 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 reduce soil erosion. The results of the LB method of treatment in general and the measurements resulting from the WS treatment specifically produced findings that were close to the results of traditional wet sieving (the Yoder method); the FW and WS treatments can simulate the effects of different amounts and intensities of rainfall and irrigation on the stability of soil aggregates. The basic principles of the Yoder method are reflected in the LB method. The LB method can not only simulate traditional wet sieving results, but can also explain the mechanisms involved in the disintegration of soil aggregates under different conditions in terms of the stability of soil structure; the LB method provides more comprehensive information than the Yoder method and can help determine the cause of the loss of soil structure. The soil aggregate structure can be accurately approximated using the LB method. The LB method can be appropriately applied to measure soil aggregate structure in the Loess Hilly-Gully Region. The MWD and the measure of the erodibility factor (K) are used to evaluate the water stability of soil aggregates. The results also showed that the MWD of soil water-stable aggregates in soils from the forest vegetation type was greater than that of soils from the forest steppe vegetation type, and SW > FW > WS; but the value of the erodibility factor (K) of soils from the forest vegetation type is lower than the value of K from soils of the forest steppe vegetation type. In areas of restored vegetation, soil water-stable aggregate varied from small particles into larger particles. Different vegetation types have diverse levels of soil organic matter content, diverse forms of soil aggregates and differences in the degree of soil aggregation present. These differences result in differences in soil erodibility and resistance to soil erosion. 参考文献 相似文献 引证文献