Study on models of degraded ecosystems in arid zone of West China

As a result of resource and environment over-used or destroyed by human beings, degradation of ecosystems has become a general phenomenon.Because of unmatched organism and non-organism elements,a series of incoordinations occurred during the process of substance recycle,energy transf ormation and information delivery in degraded ecosystems.Water is one of the most important elements in ecosystem in arid zone of West China.The development process and evolution trend of water ecosystems and its related ecosystems are restricted directly by the growth and decline of water resource. Either wetland ecosystem or desert and natural oasis ecosystems have some general characteristics while they degraded, such as, biodiversity loss,structure simplification,substance recycles derogation,energy flow abnormality, etc. Moreover,the features are obviously showed by decline of system productivity and lowering of system stability. Based on the research of characteristics and stability of different ecosystems,the rational restoration and rehabilitation countermeasures can be taken.