The Pattern Of Plant Diversity And Primary Productivity Of Lakeshore In Nansi Lake

The lakeshore is an ecotone that between the lake and the land.As the primary producers of the lakeshore,Wetland plants are important components of the ecosystem.Because of the heterogeneity of the spatial distribution of the lakeshore,the study on the diversity of plants should be based on the classification of the lakeshore.The chlorophyll fluorescence parameters and chlorophyll content are important indicators of ecosystem primary productivity and ecosystem healthBiomass of Plants is an important evaluation standard which can measure ecosystem health and stability.As the constructive species of lakeshore,Phragmites australis determines the structure of the community and the special environmental conditions.Based on the Nansi Lake,we explored the distribution of plant diversity and the primary productivity.Based on our investigations on lakeshore Nansi and combined with the remote sensing images,using software Arcgis and ERDAS,we divided lakeshore Nansi into four kinds of zone,including buildings,dry lands,ponds,and grassland.In July 2015,we chose Shannon-Wiener index,Simpson's diversity index and the relative number of plant species to assess plant diversity,we investigated and recorded the relevant vegetation parameters on the lakeshore,and analyzed the primary productivity between different kinds of lakeshores.The results showed that:(1)The plant diversity is highest in the grassland,and the lowest plant diversity is found in the buildings;and there were significant differences among the groups.(2)In the space dimension:in the summer,the F0 and Fv/Fm showed that Phragmites australis in all kinds of lakeshores are under varying degree of stress,the stress of building and dry land are most serious.The chlorophyll content of Phragmites australis of building and dry land are higher than that of ponds and the grass.In autumn,the chlorophyll fluorescence parameters showed that Phragmites australis is not under stress,and the chlorophyll content of Phragmites australis in ponds is higher than that of other kinds of lakeshore.(3)In the time dimension:the chlorophyll fluorescence parameters showed that Phragmites australis is stressed in summer,and chlorophyll content in summer is higher than that in autumn.(4)The biomass of Phragmites australis from high to low is dry lands,buildings,ponds and grassland,and there is a significant difference between them.We divided lakeshore Nansi into four kinds of zone,including buildings,dry lands,ponds,and grassland.Due to the lack of water?pollution and other reasons,plant diversity in buildings and dry lands is low,Phragmites australis is also under stress,On the other hand,because of the compensatory effect,the chlorophyll content in buildings and dry lands is higher.In the view of season,the high temperature and strong light in summer are also the reason why Phragmites australis under stress compared with in autumn,while in autumn the light is insufficient,resulting in chlorophyll content of summer is higher than that in autumn.Phragmites australis is hygrophytes,and the interspecific competition is more intense in grassland,so the biomass of Phragmites australis in ponds is higher than that of the grassland.