Soil Water Carrying Capacity for Vegetation

Abstract

Non-native plantation can effectively conserve soil and water and improve ecological environment,but soil desiccation occurs and then changes to severe desiccation in most forest and grass lands of water-limited regions, which causes soil degradation, vegetation decline and crop failure, so it is necessary to regulate the changed relationship between plant growth and soil water. However, there is a lack of a universally accepted theory to provide guidance of sustainable use of soil water resources and sustainable management of forest and sustainable produce of crop in such regions. The theory of regulating the relationship between plant growth and soil water in water-limited regions includes the Soil Water Resources Use Limit by Plant (SWRULP) and Soil Water Carrying Capacity for Vegetation (SWCCV). The SWCCV is the population in a plant population or density of indicator plants in a plant community when the soil water supply is equal to soil water consumption in the root zone and a given time, and changes with plant community type, location and time. The degree of coverage, productivity and benefits of a plant community when population quantity of an indicator plant equals SWCCV should be the theoretical basis for ensuring sustainable use of soil water resources and sustainable development of forest.