植被恢复演替的生态环境效应研究进展

Vegetation succession is a reciprocal process between vegetation and soil. The development of vegetation rehabilitation ameliorated the microclimate of the vegetation, improved soil texture and soil fertility, which in turn accelerated the vegetation succession. Increase of vegetation root in the soil improved soil resistance to erosion forces; at the same time, the accumulation of organic matter in the soil improved the content of soil aggregate, especially water stable aggregate, which helped to reduce soil erodibility and consequently soil loss. With the development vegetation rehabilitation and succession, changes of vegetation composition also changed the vegetation cover, consequently changed site hydrological characters, especially soil infiltration. Generally, highest soil infiltration was occurred under the cover of trees and shrubs, decreased on the grasslands. Currently, returning farmlands to forest and grassland was the main measures for ecological construction in West China. And the returning farmlands have becoming the important land types in West China. In the researches and practices of vegetation rehabilitation and constructions, it was important to understand the land degradation rules featured by soil types, soil erosion, soil moisture and nutrient, recognize the biological properties and adaptability to environment of related vegetation, seek feasible methods for vegetation rehabilitation in different areas with different soil types and soil erosion intensity by revealing critical threaten factors and its controlling methods, and consequently setup effective vegetation construction model for local natural conditions.