The Fluctuation Occurred In The Community Of Karelinia Caspica (Pall.) Less. After Overflow Caused By Ecological Sluices In The Lower Reaches Of Tarim River

Tarim River is famous for its abundant natural resources and fragile eco-environment. However, owning to irrational exploitation of water, land resources, the eco-environmental problems have been degraded increasingly. The nature vegetation has been degenerated completely; desert vegetation has declined comprehensive.On the basis of the overflow caused by ecological sluices in the lower reaches of Tarim River, this paper investigates the characteristics of the fluctuation in the community of Karelinia caspica (Pal1.) Less. The objectives were as follows: to clarify the community response after the overflow caused by ecological sluices; master the dynamic variation rule in all aspects in the community of Karelinia caspica (Pal1.) Less. ; to obtain the fluctuation intensity; obtains the type of fluctuation; to understand the effect of the overflow. The purpose is to provide academic sustainment to the protection and restoration of the degenerating vegetation in the lower reaches of Tarim River and other arid area.The result obtained showed that the fluctuation occurred in the community of Karelinia caspica (Pal1.) Less. after the overflow caused by ecological sluices. The species composition trends to complex; the species important value and the niche breadth has decreased; while Shannon-Wiener diversity, the species richness, evenness index, dominance index, vegetation coverage and the average biomass per m2 has increased. The changing trend and degree of every characterization value is different, indicating that the fluctuation occurred in the community of Karelinia caspica (Pal1.) Less. has regularity and complexity. The fluctuation of every characterization value is Positive fluctuation.The research can be concluded as flows: fluctuation occurred in the community of Karelinia caspica (Pal1.) Less. after the overflow caused by ecological sluices; The community structure toward to optimal and complex. The overflow caused by ecological sluices is an economical and effective method for the restoration of herbaceous plant community.The main cause of the fluctuation occurred in the community of Karelinia caspica (Pal1.) Less. : conditions of environmental resources were improved by the overflow and the contribution of germplasm bank.The main creative point include: The research object selected doesn't repeat the previous research. The previous research of overflow in arid area seldom involves, especially research of the overflow caused by ecological sluices. Study on the fluctuation occurred in the herbaceous plant community is reported for the first time in the lower reaches of Tarim Rive. This paper described the restorative effect of overflow caused by ecological sluices to the herbaceous plant community for the first time. And there is seldom system research on the community of Karelinia caspica (Pal1.) Less.