半干旱区人工林草地土壤旱化与土壤水分植被承载力  

Soil water carrying capacity of vegetation and soil desiccation in artificial forestry and grassland in semi-arid regions of the Loess Plateau

作　　者：郭忠升[1] 邵明安[1,2] 

机构地区：[1]中国科学院,水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,西北农业科技大学,陕西杨凌712100 [2]中国科学院地理科学与资源研究所,北京100101

出　　处：《生态学报》2003年第8期1640-1647,共8页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目 ( G2 0 0 0 0 1 860 5 );中国科学院资环局知识创新重要方向资助项目( KZCX2 -41 1 ) ;国家自然科学基金重点资助项目 ( 3 0 2 3 0 2 90 )~~

摘　　要：近年来在黄土高原地区多年生林草地 ,出现了以土壤旱化为主要特征的土壤退化现象。退化土壤反过来影响植物的生长和发育 ,最终将导致植物群落衰败和生态系统的退化 ,从而影响到林草植被的长期稳定 ,经济效益和生态效益的持续稳定发挥 ,这已成为当前林草植被建设的重大问题之一。分析了土壤旱化现象与土壤干层的关系 ,探讨了土壤干层的划分标准。认为防止土壤旱化的主要措施就是控制林草地密度和生产力 ,而控制林草地密度和生产力的理论依据就是土地植被承载力。在黄土高原大部分地区植物吸收和利用的土壤水分主要依靠当地的天然降水 ,土壤水分是限制植物生长的决定因子 ,该类地区土地植被承载力实质上为土壤水分的植被承载力。作者定义土壤水分植被承载力为土壤水分承载植物的最大负荷。它是指在较长时期内 ,在现有的条件下 ,当植物根系可吸收和利用土层范围内土壤水分消耗量等于或小于土壤水分补给量时 ,所能维持特定植物群落健康生长的最大密度。探讨了土壤水分植被承载力的确定方法和影响因素 ,认为凡是影响林草地土壤水分的补给和消耗 ,植物群落生长发育和植物水分利用效率的因素 ,包括地理位置、地形、气候、植被类型及其发育阶段 ,抚育管理措施都影响土壤水分植被承载力数值。开展土壤水分植被承?Recently, soil deterioration appeared on the Loess Plateau in the form of excessive soil drying under perennial grasses and forests. Excessively dry soil influences the growth and development, stabilization, economic and ecological benefits of plant communities, which is one of the most important problems of vegetation rehabilitation. In this paper, the authors analyzed the relationship between soil desiccation and drying of the root zone soil layer, developed an approach to determine the limit of root zone drying, and considered that the main measure to control soil desiccation is to control the density and productivity of a vegetation community which is related to the theory of the land's carrying capacity of vegetation. Plant water uptake and utilization mainly depends on soil water, and the soil water is related to the precipitation. Soil water is the most important factor influencing plant growth and development in most of the Loess Plateau. The land's carrying capacity of vegetation in this region is mostly affected by soil water. The term soil water carrying capacity of vegetation was developed and defined as the ability of soil water to carry vegetation. The limit is the largest density of the vegetation community when soil water consumption is equal to or lower than soil water supply in the root zone soil layers from which plant roots can take and utilize water on an annual basis under modern management conditions. The authors provide preliminary discussion of the method and the factors influencing soil water carrying capacity of vegetation, and considered that all of the factors which influence the soil water consumption and soil water supply, plant community growth and development and the water utilization coefficient of plant including geography, topography, climate, vegetation type and plant development stage, will influence the level of soil water carrying capacity of vegetation. It is important to conduct further research on soil water carrying capacity of vegetation for forest and grassland manage

关 键 词：黄土高原 林草地 土壤旱化 土壤干层 防治措施 土壤水分植被承载力 

分 类 号：S154[农业科学—土壤学]