THE PRELIMINARY DISCUSSION ON SOIL DESICCATION OF ARTIFICIAL VEGETATION IN THE NORTHERN REGIONS OF CHINA
Yang Weixi(Beijing Forestry University Beijing 100083)
The serious soil drification, which is being confronted in the course of construction of artificial vegetation represented by artificial plantation in the northern regions of China, is put forward in this paper. Soil desiccation is the mainly expressive form of soil deterioration of artificial vegetation in northern regions where there is less precipatation,the principal characteristic of soil desiccation is critical deficit of soil water continuously for a long time in the affecting scope of plant root system because of extra transpration of plant. The precipitation cannot compensate for water consumption effectively, surface soil crusts and soil compactness increases, which results in obvious declination of plant growth, even make plant shivelled and dead in the range of large area. The soil desiccation has become seriously potential danger of the construction of artificial vegetation in tills region. In my opinion, the direct reason, which causes soil desiccation of artificial vegetation, is the improper selection of vegetation type, too high community density and too high community productivity. The prevention and control strategy is as the follows:In the guidance of correct thought of vegetation construction, according to local bio-climatic productivity, vegetation type is selected in the light of local condition, community density is decreased subtantially,community productivity is adjusted and controled rationally, the final purpose is to keep balance between water consumption by plant transpiration and compensation of soil water, to further keep continuous stability and high yield of community.