Study Of The Spatiotemporal Variation Of The Water And Soil Elements Of The Multi-level Shelter Forest

Because of the factors of the global warming and human activities, the areas of the natural vegetation in the arid and semi-arid areas are reduced drastically. And, more and more soli has been desertificated. The study of the spatial and temporal variations of the water and soil elements of the Multi-level shelter forest not only be conducived for the system of the shelter forest, and to provide a theoretical basis for the development of the shelter forest, but also plays a vital role in the local economic development and ecological environment improvement process. Based on the TM images of the Moyu County, we use the ArcGIS, ENVI to analysis the landscape pattern. Meanwhile, the sheltering effect, the spatial and temporal variations of the warer and soil elements was studied. The results are showed as follows:(1) The cultivated land has the biggest NP number on the Moyu County of different land use types, meanwhile its area has only1.78%of the county's area. So we can say that Moyu County has a high landscape heterogeneity. And, the distribution of space is uneven. At the same time, the farmland has a larger PD, it has a high degree of fragmentation and scattered in the county. LPI value of the sand reached to36.2229%, meanwhile the LPI value of woodland transition zone grass is very small. So we can say that Moyu County is in the threaten of the desertification.(2) As the shelter forest of the artificial planting of vegetation planted, the soil moisture, the soil nutrients was showed an upward trend, while the soil salinity, nutrients, pH was showed a downward trend. And area collocated with multiplants using configurations are ideal. But its soil salt contents was significantly higher than the other.(3) The planting patterns of the Elaeagnus+Tamarix has the best effect in improving the soil physical and chemical properties. The patterns of Elaeagnus oxcarpa Schlech's soil has the maximum water content, while the soil water storage ability is obviously higher. The planting patterns of the Tamarix is most conducive in temperature decreasing, and, with the relative soil moisture content increases, the soil temperature decreased. Although the populus is salt resistance and drought tolerance, and had the very strong vitality, its survival is significantly lower than the others in in the Moyu's Eco-Industrial Area. So we can say that the populus is not suitable for the area.(4) The multi-level shelter forest of the ecosystem service value is0.10%of the Moyu County's2009gross national product, while its area is only0.01%of the county area.So it shows that shelter forest value of ecosystem services is a major wealth of the earth. Meanwhile, Variety of plants configurations has the most soil fertility among the different measures in the sand control project. It has reached266.67yuan/hm2, so we can say that area collocated with multiplants has a higher soil fertility than grass grid and artificial forest.