Studies On Hydrophytes Diversity Of Wetland In Beijing

The diversity of wetland hydrophytes in Beijing analyzed thoroughly. Comparability of wetlands was identified, and the establishment strategies of wetland nature reserves were proposed. The research can be thought the theoretics support of carrying out of wetland conservation project. Totally 20 wetlands in Beijing were investigated, including 13 rivers and 7 reservoirs. Investigation area included water body, transition area between water and land. The area of hydrophyte squares was 0.5m×0.5m, and names of species, the coverage, and the biomass were recorded. The area of herby squares was 1 m2, the depth of water, the names of species, the individual amount, the average height, and the coverage were recorded.Total 42 hydrophyte species had been recorded, and belonged to 22 families and 29 genera. The hydrophyte included emergent aquatic plants(13 species), floating-leaved macrophtes(12 species), submersed maciophtes (17 species). The popular hydrophyte included Phragmites australis,Typha angustifolia,Hydrilla verticillata,Myriophyllum spicatum,Ceratophyllum demersum,Potamogeton crispus and Lemna minor.Dased on distribution of hydrophyte, TWINSPAN divided 20 wetlands into 6 groups. Guihe River,Huairou Reservoir, and Huaisha-huaijiuhe River composed one group by higher diversity and similar composing of species. Jinniuhu Lake and Tanghe River become one group because there were special species in them. Guanting Reservoir,Hanshiqiao Reservoir,and Miyun Reservoir become one group because they had similar environment. Baihe River,Jumahe River,Qingshuihe River,and Yongdinghe River became one group because they had similar environment too. Chaohe River,Dashihe River,Jinhaihe Lake,and Shisanling Reservoir became one group because similar environment and degree of human disturbance.Beiyunhe River,Beishahe River,Liangshuihe River and Wenyuhe River became one group because of lower plant diversity.There were 4 critically endangered species, Butomus umbellatus, Vallisneria natans, Najas graminea,and N.minor; 5 endangered species, Batrachium pekinense,B.bungei,Trapella sinensis,Polygonum amphibiumand P.distinctus; 9 lower risk species,such as Nasturtium officinale,Salvinia natans,Marsilea quadrifolia ;safty species 24,like N.marina,P.maackianus and so on.Community biodiversity and structure of hydrophytes which related to water depth,numbers of species and biomass, important value,and biodiversity were studied on Huairou Reservoir, Huaisha-huaijiuhe River,Tanghe River,Jinniuhu Lake and Jumahe River.Based of analysis on wetland degradation reasons, several countermeasures of restoration and protection were suggested in the thesis.