Study On Plant Community Biomass Of Typical Urban Lake Wetland In Wuhan

Based on the investigation of plant species,community types and biomass of nine typical urban lake wetland of central district in wuhan,vegetation types and its regularities of distribution of main wetland as well as plant biomass and its influence factor of urban wetland were analyzed,therefore ecosystem services value in regard to carbon fixation and oxygen release of lake wetland of central district in wuhan were discussed. To provide reference for quantitative measurement of wetland ecological assets and wetland ecosystem,to offer basic data for research on biological productivity,nutrient cycling and energy flow of wetland ecosystem,and to provide the foundation for urban wetland planning and construction as well as wetland plant protection and recovery.The major findings were as follows:1.Urban lake wetland in wuhan were rich in 297 species of plants belonging to 99 families,232 genera.Classified by life form:97 species were arbors belonging to 38 families,65 genera;43 species were Shrubs belonging to 28 families,36 genera;96 species were herbaceous plants belonging to 33 families,85 genera;19 species were vines belonging to 10 families,13 genera;60 species were aquatic plantsbelonging to 24 families,45 genera that included 40 emergent plants belonging to 36 genera and 13 families,9 floating plants belonging to 8 genera and 7 families,11 submersed plants belonging to 7 genera and 5 families.Dominant species of arbor were Salicaceae and Pinaceae;dominant species of shrub was Rosaceae;dominant species of herbaceous plant were Gramineae,Cyperaceae,Leguminosae and Compositae;dominant families of hygrophyte plant were Polygonaceae,Nymphaeaceae etc,and each families spread scattered in genera lever.2.Coenotype of 9 typical urban lake wetland of central district in wuhan included 5 vegetation types which were woody swamp,tussock,emergent vegetation,floating vegetation and submersed vegetation,containing 50 associations and 27 formations.Woody swamp vegetation types were distributed in each lakes, just like in the grass,marsh and associated forest, furthermore,together with the emergent plants adjoined to the lakeshore, extending as floating plants and submerged plants to the lake waters. Among them, the most common associations of lake wetland in wuhan were camphor tree formation, loose formation, structure tree formation, Typha formation,lotus association,reed formations,formation water hyacinth, A.philoxeroides association,Bermudagrass and Roegneria Ass Ass,bitter grass formations, Myriophyllum formations and so on.3.Determination results of vegetation biomass of the typical urban lake wetland buffer showed:per unit area biomass of semi-natural lakes,Dong Lake.Yue Lake and Zhuye sea, were 1418.40.1373.50.694.70 g·m-2, an average of 1262.60 g·m-2;per unit area biomass of natural lakes,strict Yandong Lake.Ye Lake and Sanjiao Lake, were 1068.33.1177.50.928.40 g·m-2, an average of 1058.08 g·m-2;per unit area biomass of artificial lakes, Ziyang Lake, Lingjiao Lake and Bei Lake, were 465.11,220.01.210.10g·m-2, an average of 298.41 g·m-2.In diffirent disturbance types, per unit area biomass of Lake buffer vegetation showed:semi-natural lakes> natural lakes> artificial lakes.4.Determination results of aquatic plants biomass of typical urban lakes showed: per unit area biomass of Natural lakes, Yandong Lake,Ye Lake and Sanjiao Lake, were 147.24.151.62.204.24 g·m-2, an average of 167.70 g·m-2;per unit area biomass of semi-natural lakes,Dong Lake.Yue Lake and Zhuye Lake,were 5.73. 107.18.68.83 g·m-2, an average of 60.58 g·m-2;per unit area biomass of artificial lakes,Ziyang Lake.Lingjiao Lake and Bei Lake, were 17.79.7.11.13.59 g·m-2, an average of 12.83 g·m-2. The greater of human disturbance degrees, the smaller of per unit area biomass of aquatic plants, in other words, natural lakes> semi-natural lakes> artificial lakes.5.There was a significant positive correlation among total plant biomass,water area and shoreline length of the typical urban lakes,the overall trend of total biomass of different lake types:natural type lakes> semi-natural lakes> artificial lakes,furthermore plants biomass of artificial lakes and semi-natural lakes buffers accounting for more than 80% of the total biomass,however,biomass of natural lakes has a proportion of about 50%. Therefore, to ensure maximising ecological functions of lake vegetation, for artificial lakes and semi-natural lakes,buffer vegetation should be protected and aquatic vegetation should be appropriately increased;but for natural lakes,buffer vegetation as well as lake water area should be protected at the same time.6.Results for analysing utility values of typical lake wetland in Wuhan:amount of value of water conservation and storage services of 38 lakes in central district of Wuhan were 0.15×108 yuan; the existing amount of value of carbon fixation and oxygen release were 379.61×104 yuan,semi-natural lakes had the highest contribution,followed by natural lakes,and artificial lakes were the lowest, respectively, accounting for 71.10%,28.64% and 0.26% of the total biomass.7.The typical 38 wetland lakes of the central district in Wuhan belonging to six different regions (Hongshan District,Wuchang District,Hanyang District,Qiaokou, riverbank area, Jianghan District), which, Hongshan District has the largest the water area and carbon sequestration and oxygen release Value of respectively 89.20%,83.2%;followed by the Hanyang District, has the proportion of carbon sequestration and oxygen release Value of 14.83%,while Qiaokou has only 1.04% of total fixed carbon and releasing oxygen value, the District of riverbank, Wuchang, and Jianghan Value of total fixed carbon and releasing oxygen are all below 1%.