Effect Of The Different Vegetation Restoration Models On Ecosystem Environment At The Edge Of Desert

Farmland desertification is a main type of desertification. It leads to land degeneration including land production descending, soil loss, and the desert likelihood landscape, which is always attributed to the interaction between irrational human activity and the weak ecosystem. In China, one of the countries with most serious desertification, land desertification has become the biggest obstacle to the sustainable development of source, society and economy in its western region, especially the arid and semiarid area in Chinese northwest region.Gurbantunggut Desert is the largest fixed and half fixed desert in china. In it, the vegetation on its edge is destroyed seriously, the dune activation significant, and precipitation scarce and uneven. During the last twenty years, with the vegetation destroyed, the activation area of the fixed and half fixed dune in the northern part has become larger and larger, the wind speed bigger and bigger. In the mean time, the quicksand in the southern part has expanding to the oasis. Therefore, how to defend the wind and fix the sand effectively has become the most urgency problem.Based on the longtime investigation in the fixed site of Qitai county locating on the edge of Gurbantunggut Desert, we investigate the status of desertification under the different reconverting modes. With the data got from field sampling and wind investigation, soil analysis in the lab, we try to find out the different effects on the wind-defending between natural and human-made vegetation area, and the effects of the two types of sand-defending forest belts on the different geographical environments. We find that, the human-made vegetation reconverting mode has the more significant defending effects on the wind speed and kinetic energy than the natural vegetation reconverting mode. Contrasting to the natural vegetation area, the human-made vegetation area has 58.8 more wind-without days a year, descend 0.88m per second on the mean wind speed in a year, and reduce 65.2 percent of wind kinetic energy a year. The human-made vegetation has the most significant effects on the northward and northwest winds, and the least significant effects on the southwest wind. There are different preservations of biodiversity between different vegetation reconverting mode. Contrasting to the community of human-made vegetation, the one of natural vegetation has more abundant species, higher stability, and stronger power to maintain, develop and keep the plant diversity. The human-made vegetation reconverting mode is able to reduce the salinity and the PH of the soil in the front edge of the desert, but has little effect on the soil organic matter.