Study On The Relationship Between Soil Moisture And Community Characteristics Of Populus Euphratica In The Natural Reserve Of Ejina

Populus euphratica is an only arbor species that can build groups in desert of natural distribution. It maintains the ecological balance of distribution area to protect oasis agricultural production, livelihood of the residents for its characters including salt-tolerant,m aintaining water, anti-drought,and anti-sand,which leads to higher ec ological,economic and social value. For near half a centuyr,the area of natural Populus euphratica community in Ejina natural oasis has reduced sharply as the results of sharp decrease in the amount of regional water, the deterioration of ecological environment. So it is of utmost importance to protect Populus euphratica, which can promote the restoration of regional desert vegetation specially. Ecological characteristics and habitat of Populus euphratica are discussed in this paper. The intention is to disclose regeneration and restoration mechanism of Populus euphratica population and community. Such relative aspects including ecological adaptation of Populus euphratica and Populus euphratica forest community biodiversity characteristic in successive proceedings, as between age, density, and degree of shade, between Populus euphratica forest community biodiversity index and evenness index, and soil water content, underground water depth ,as well as the variability of soil moisture content of Populus Euphratica,which can provide scientific basis for effective p rotection of Populus euphratica community and restoration of desetr vegetation. The results showed:(1)The majority of Populus euphratica community consists of Populus euphratica. Its density is relatively low and so does degree of vegetation shade.(2)Biodiversity index and evenness index are obviously related to age and density of Populus euphratica, and unrelated to degree of shade; density and age are relative to evenness index. With the of Populus euphratica age growth, the biodiversity index and evenness index are increasing, while the numbers of species and individual is decreasing. The regression relations between age and density of Populus euphratica shows there is obviously dispersal effect among the individual of even aged forest. (3)The soil water content orders from high to low are: young aged forest, middle aged forest, near matured forest and over matured forest. This is because different aged Populus euphratica forest their roots prosper differently, the mature forest have large amount of roots, their ability of utilizing underground water and transpiration are both high, besides, different aged Populus euphratica forest means that the amount of growth is different as well ,making the water depletion rate differently.