The Distribution Characteristics Of Vegetation Diversity In Bosten Lake Wetlands In Xinjiang

Bosten Lake is the largest inland freshwater lake in China, which was the natural regulating reservoir basin to Kai- Kong River. Lakeside wetland vegetation was good at water conservation, reclamation siltation, pollution mitigation, maintaining ecological balance and keeping biodiversity, which acted a very important role as a natural protective barrier of the lake. Taking the Lakeside wetland of Bosten as the study area and the lakeside wetland vegetation for the study, aimed to revealing the plant community diversity and distribution mechanism to maintain diversity. There was the results:The quadrat method was used to investigate natural community patch characteristics such as area, perimeter and shape index in lakeside of Bosten Lake. Four indices were selected to describe plant diversity: richness(R), Simpson(D), Shannon-Wiener(H), and Pielou(E). The results show that the 28 patches of lakeside of Bosten Lake were recorded 53 species of vascular plants of 22 families and 47 genera. Phragmites australis, Tamarix ramosissima, Populus euphratica and Typha angustata are common population of plant construction group in the area, which indicating wetland ecosystem in arid area. Our data suggested that, significant correlations were observed between the R index and patch area(r= 0.594, p=0.001) and perimeter(r= 0.522, p=0.004), no correlations were noted for the shape index, D, Hand E indices. Additionally, R, D and H indices of different layers were as follows: large patches> medium patches > small patches. Diversity levels remained relatively high after human disturbance. The greatest difference among patches was noted in large patches. Plant species richness increased with patch area and perimeter, most likely resulting from edge effects. Our results demonstrated that the patches area plays an important role in preserving plant diversity in the region.TWINSPAN, DCA, CCA and RDA methods were used to classify the plant community types and.TWINSPAN results showed that the vegetation in this region could be divided into 7 associations, which are distributed in lakeside shallow water zone, lakeside marshes zone, bushes and trees lakeshore zone and xeric shrubs zone. These associations can be named as follows: Typha angustata, Phragmites australis + T. angustata, P. australis + T. angustifolia, Tamarix ramosissima – P. australis, Populus euphratica – T. ramosissima, Salix matsudana – T. ramosissima, T. ramosissima. And they were well reflected in the DCA ordination graph.CCA and RDA results showed vegetation distribution patterns correlated with major environmental variables and the relationship between vegetation species diversity and environmental factors in order to evaluate the influence of environment regulation on vegetation in the lakeside of Bosten Lake, Xinjiang. The decisive factors of this 13 soil environmental factors were soil water content and total dissolved solids and total phosphorus. Soil water content was the most important soil environmental factors.