冻融作用对藏东南高寒区土壤容重、孔隙度的影响  

Effects of Freeze-Thaw on Soil Bulk Density and Porosity in Alpine Region of Southeastern Tibet

作　　者：姚甜甜 聂晓刚张鹏 杨东升[1,2] 万丹[1,2] YAO Tiantian;NIE Xiaogang;ZHANG Peng;YANG Dongsheng;WAN Dan(Resources&Environment College,Tibet Agriculture&Animal Husbandry University;Research Center for Alpine and Soil Conservation of Tibet Agriculture&Animal Husbandry College,Nyingchi Tibet,860000;Tibet Autonomous Region Forestry Investigation and Planning Institute,Lhasa Tibet,850000,China)

机构地区：[1]西藏农牧学院资源与环境学院 [2]西藏农牧学院高寒水土保持研究中心,西藏林芝860000 [3]西藏自治区林业调查规划研究院,西藏拉萨850000

出　　处：《高原农业》2020年第4期386-391,共6页Journal of Plateau Agriculture

基　　金：高原生态安全实验室开放基金(STX2019-10)。

摘　　要：青藏高原冻融交替频繁,反复的冻融过程破碎土体,破坏土壤物理结构和性质,促进土壤侵蚀发育,不利于区域生态环境的稳定和维护。本文以色季拉山山顶季节性土壤为研究对象,考虑土壤初始含水率和冻结温度两个因素,采用室内模拟冻融循环试验方法,探讨土壤容重和孔隙度在冻融循环作用下的变化规律。结果表明:(1)土壤容重和孔隙度的变化与冻融循环次数、初始含水率以及冻结温度之间存在极显著关系(P<0.01);(2)随着冻融循环次数的增加,土壤的容重呈减小趋势,而土壤孔隙度呈增大趋势,在5次循环以后趋于稳定;(3)高含水率土壤较低含水率土壤容重更大,孔隙度更小,且高含水率土壤中冻融循环过程中,其变化幅度比低含水率土壤小;(4)冻结温度越低,在冻融循环过程中土壤容重表现为较低的数值,而孔隙度相对较大,且二者变化幅度最大。The frequent freezing-thawing process in the Qinghai-Tibet plateau,which breaks the soil,damages the physical structure and properties of the soil,and promotes the development of soil erosion,is not conducive to the stability and maintenance of the regional ecological environment.Taking the seasonal soil of Sygera Mountain as the research object and considering the two factors:initial soil moisture content and freezing temperature,through the indoo freeze-thaw cycle test study,this paper discusses the variation of soil bulk density and porosity under the action of freeze-thaw cycle.The results show that:(1)there is a very significant relationship between changes in soil bulk density and porosity and the number of freeze-thaw cycles,initial moisture content,and freezing temperature(P<0.01);(2)as the number of freeze-thaw cycles increases,the bulk density of the soil decreases,and the soil porosity increases,tending to stabilize after 5 cycles;(3)the soil with high moisture content has larger bulk density and smaller porosity than the soil with low moisture content,and the change range of soil with high moisture content is smaller than that with low moisture content during freeze-thaw cycle;(4)the lower the freezing temperature is,the lower the soil bulk density is,and the porosity is relatively large,and the two have the largest changes.

关 键 词：色季拉山 冻融循环 容重 孔隙度 

分 类 号：S157.1[农业科学—土壤学]