Geoecology Of The Ejina Basin In North-Western Arid Region, P.R.China

The ecological environment in NW China is intrinsically vulnerable and has been destroyed greatly in the past decades as a result of large-scale land reclamation, over grazing, and intensive exploitation of water resources. A lot of environmental problems including vegetation degradation, desertization, and salinization, are developing rapidly in the area. It has seriously affected local economic and ecological sustainable development, and it strengthened the disequilibrium of the social development of the western and eastern of China, and will finally hinder the development of ecological environment quality and social economy of eastern China. China has put forward the national strategy of accelerated development of western China. The action will be right to narrow the disparity of the western and eastern, improve the poor areas' economic development, reform the ecological environment, and consolidate social stability and nationality unity.Ejina Desert Plain in the lower reaches of Heihe River is the one of the most arid region's in Inner Mongolia, where ecological environment has been extremely vulnerable. Since 1960's, the water quantity of the surface to Ejina Basin has been reduced. It caused the ecological environment degradation with time, and the flourishing oasis in the past has already desolated, where water head and lake dry up, arable land waste, desert increase, vegetation degradation. The problem about water resource reasonable utilization in Heihe River drainage area and Ejina Basin's ecology degradation in the lower reaches of Heihe River has been the focus of attention domestically and internationally.The plant community which is regarded as the basic composition of the ecological environment has special importance to the characteristic function of the whole ecosystem in Ejina Basin, furthermore in the whole arid regions of NW China, and it is not merely determining the distribution and migration of the animal, but also is determining living conditions of human being by controlling local climate characteristic and water and heat exchanging Therefore, the course of the ecological construction and ecological restoration is the one of the vegetation building and vegetation recovering in fact. However the habitat has decisive role in controlling to the vegetation distribution and quality: the macroscopic disposition of the geological environment determines the distribution pattern of the vegetation on the area, and it forms the unique macroscopic vegetation zonation; the small scale heterogeneity of geological environment makes different locations in the same vegetation zonation take on the different landscape pattern. In order to rebuild the ecological environment in the arid interior basin of Northwest China, wemust launch on studying the relation between the bio-community and the research of the geological environment, namely the geo-ecological research. Ejina Basin in the low reaches of Heihe River the typical representative of the Northwest arid district of interior basin. There is very important meaning to select the areas to study the theory of geoecology , and it can improve the geo-ecological investigation, the deficiency of the theory and method at present. Furthermore, it can also guide the ecological construction of the studying area, and has important referenced function to the other areas.The paper was supported by the special plan of Science and Technology in the Year 2000 of the Ministry of Land and Resources of China, which is The Study on development of water resources of Heihe River drainage area in the Gansu Corridor to the impact of ecological environment (NO.200010302), the second item of The water resource sustainable utilization in the Northwest China. The Focus of understanding the interaction between basin's vegetation degradation and geological environment as the research object, and the following scientific questions were to be answered through the research work: (1) the geo-ecological analysis on natural plant community succession; (2) the geological environment condition on...