A Study On Plant Community Structure And Variation Of Wetland In Dashanbao Black-necked Crane National Natural Reserve, Yunnan, China

Wetland vegetation in Dashanbao Black-necked Crane National Natural Reserve, Yunnan, were surveyed by the methods of gird plotting and photography for two years (2014～2015). Community structure, important value, and species diversity were analyzed by NMDS ordination under the different habitats and management regimes. Aimed to reveal effect of the main environmental fators to community structure changes, and to explore influence of community structure under different management methods. The major results were as follows:1) The NMDS ordination well indicated the relationship of plants communities with environmental gradients (stress<5%). Through the comprehensive analysis, we categorized 4 types of habitat. The organic matters, soil moisture content, soil bulk density, and available phosphorus content were the primary environmental factors, which determined the distribution characteristics of wetland vegetation. The analysis results of a diversity indexes between different habitats indicated that species richness and Shannon-Wiener index decreased from mesophytic habitat to hydric habitat.2) Species height, the coverage of Gramineae and Cyperaceae plants, and richness index significantly increased in two years of fencing management, meanwhile, the quantity of forb species decreased. Shannon-Wiener index, evenness index, community structure and functional groups did not changed obviously in two years.In 2015, the number of annual herbs, for example, Pedicularis gracilis and Eleocharis yokoscensis in control samples were greater than 2014, however, hygrophyte and aquatic plants population revealed the opposite trend.3) The variation characteristics of study area in two managed plots were different. Most of the community types in Dafazitang had no obviously change between 2 years, but in Xiaohaiba fenced plot, the number of community type, which wet plants were dominant, was great in 2015 than in 2014. However, mesophytic community became fewer in 2015.4) In managed plots, the community biomass in 2015 was higher than 2014. In unmanaged sample, the community biomass had no significantly change between 2 years.This study can provide a basic information and reference about wetland protection and habitat management of Black-necked Crane.