放牧对内蒙古大针茅草原土壤剪切力空间分布的影响  

Effects of grazing on spatial distribution of shear strength in Inner Mongolia Grassland

作　　者：甘磊[1,2,3,4] 彭新华[3] 谢永雄[1,2] 钟家尚 Stephan PETH Rainer HORM 

机构地区：[1]桂林理工大学广西矿冶与环境科学实验中心,广西桂林541004 [2]桂林理工大学环境科学与工程学院,广西桂林541004 [3]土壤与农业可持续发展国家重点实验室,中国科学院南京土壤研究所,江苏南京210008 [4]Institute of Plant Nutrition and Soil Science,Christian-Albrechts-University zu Kiel

出　　处：《草业科学》2014年第2期219-223,共5页Pratacultural Science

基　　金：广西矿冶与环境科学试验中心项目(KH2012ZD004);德国科学基金会(Forschergruppe 536);国家重点基础研究发展计划(2013CB429902);桂林理工大学博士启动项目(2012027)

摘　　要：本研究在内蒙古草原生态系统研究站的持续放牧(CG)和禁牧(UG79,从1979年开始禁牧)两个试验区。利用GPS在每个区分别设立1个长135m×105m的样地,每样地选100个测量点,利用Hand-held vane tester测量土壤剪切力并研究其空间分布情况。结果表明,CG区,放牧导致土壤孔隙减少,容重增加,有机质减少,土壤剪切力高于凋落物与有机质较多的禁牧小区。在UG79和CG两个区,从干旱条件到中等水分条件,土壤剪切力空间分布都有差异,说明土壤含水量在一定程度上决定了土壤剪切力的空间分布,但到达湿润条件后,其分布有恢复原状的趋势,这暗示土壤水分对其影响也存在限制。To understand the change of soil shear strength and its’ spatial distribution, two sites： Continuous Grazing （CG） and Un-grazed since 1979 （UG79） were investigated by Hand-held vane tester. In each site, a regular sampling grid which covered an area of 105 m×135 m and included 100 points was positioned by GPS. The results showed that, CG induced the reduction of porosity and the increase in bulk density which resulted in the greater shear strength than UG79 within higher litter and soil organic matter. At both UG79 and CG sites, the obvious difference in spatial distribution of shear strength from dry soil water condition to moderate soil water condition indicated that soil water content, at some extent, determined the spatial distribution of shear strength. However, such capacity was limited when soil water content increased, which suggested that soil has the ability to maintain spatial distribution of shear strength itself.

关 键 词：放牧 土壤剪切力 空间分布 土壤水分 

分 类 号：S812[农业科学—草业科学]