黄土高原不同退耕还林植被土壤干燥化效应  

Effects of Different Revegetation Types on Soil Desiccation in the Loess Plateau

作　　者：梁海斌 薛亚永 安文明[1,2] 王帅 李宗善 吕一河 LIANG Haibin1，2，XUE Yayong3，AN Wenming1,2,WANG Shuai1,LI Zongshan1,LüYihe 1(1. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beij ing 100085, China; 2. University of Chinese Academy of Sciences, Beij ing 100049, China ; 3. Key Laboratory of West China Is Environmental System ,Ministry of Education, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Chin)

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [2]中国科学院大学,北京100049 [3]兰州大学资源环境学院西部环境教育部重点实验室,兰州730000

出　　处：《水土保持研究》2018年第4期77-85,共9页Research of Soil and Water Conservation

基　　金：国家自然科学基金(41390462;41571503);环保公益项目(201409055)

摘　　要：土壤水分是黄土高原植被恢复的主要限制因子,退耕还林工程在恢复生态环境的同时也造成了区域土壤含水量下降和土壤干燥程度的加剧,土壤干燥化正日益威胁到土壤水资源的持续利用和人工植被建设的成效。选取黄土高原退耕还林试点县吴起境内刺槐、杏树、柠条和沙棘4种分布广泛的退耕植被类型,对照撂荒草地,分析了不同林龄和不同植被类型样地0—500cm的土壤水分特征和土壤干燥化效应,并根据作物耗水量估算土壤干层水分的恢复时间。结果表明:不同退耕还林植被类型样地土壤含水量由表层向深层呈降低趋势,随林龄增加,各植被类型样地土壤含水量、有效储水量逐渐减少。刺槐林土壤含水量较同龄沙棘和柠条林低,而杏树林则较同龄柠条林高。各植被类型样地土壤剖面均不含渗透重力水与极易效水层,随林龄增加,土壤相对湿度及易效水土层厚度占比逐渐减少,中效水、难效—无效水土层厚度逐渐增加。随林龄和土层深度的增加,各植被类型样地土壤干燥化强度、土壤干层厚度逐渐增加,土壤湿度恢复到土壤稳定湿度所需要的时间及难度呈上升趋势。Soil moisture is the main limiting factor affecting vegetation restoration in the vast Loess Plateau.Since Grain-for-Green Project was conducted in 1999,vegetation coverage has increased significantly,and soil and water loss has been alleviated.However,on the other hand,as ecological water use of vegetation increased,it has resulted in decrease of soil moisture content and aggravated soil desiccation.Soil desiccation has been seriously threatened the sustainable and healthy use of soil water resource as well as the vegetation construction.In the present study,a representative county,Wuqi County,located in northwestern Loess Plateau,was selected.Four different revegetation types（Robinia pseudoacacia,Prunus armeniaca,Caragana korshinskii,Hippophae rhamnoides）with various forest ages（10-year,15-year,18-year,20-year,25-year,30-year,38-year,42-year as well as 50-year）were selected to measure the soil moisture contents and soil desiccation intensity in 0—500 cm soil profiles.Soil moisture availability,together with desiccated soil layers′recovery was also estimated based on annual crop water consumption.The results indicated that soil moisture contents of different revegetation types decreased from surface to deep soil layers,soil moisture in 0—100 cm soil depth varied actively,while below 100 cm it kept relatively stable;as forest age increased,soil moisture contents,available soil moisture storage gradually declined,while soil moisture over consumption showed an increasing tendency;soil moisture content in Robinia pseudoacacia was lower than that in Caragana korshinskii and Hippophae rhamnoides shrub-lands with the same forest age,whereas soil moisture content in Prunus armeniaca was a little higher than even-aged Caragana korshinskii;moreover,there was no infiltration gravitational moisture and most easily available soil moisture in each sampling plot;withthe increase of forest age,relative soil moisture and the ratio of easily available soil moisture to soil profiles decreased,while the thickness of m

关 键 词：土壤干燥化 退耕还林 土壤含水量 黄土高原 

分 类 号：S727.21[农业科学—林木遗传育种] S157[农业科学—林学]