Study On The Reconstruction Model Of Aquatic Macrophyte Community In Adlittoral Mining Subsidence Wetland

Aquatic plants is the key link in nutriention circulation of the lake ecosystem. It is the necessary condition for the ecosystem to maintain the water steady state. It is the material base on which the food chain.An optimization of the community of the aquatic higher plants is necessary to construct a steady water ecosystem, especially for the recovery of the submerged plants.The aquatic higher plants is an important primary producers in aquatic ecosystems. It is an important regulators of water environment. It’s can provide spawning grounds and food for fish, supply fattening habitats and provide shelter for zooplankton. The large aquatic plants can improve the biodiversity and stability of the lake ecosystem. Submerged plant, as an important element of lake ecological system, can absorb the nutrients such as nitrogen, phosphorus in water body. It has important ecological value to mainten the lake ecosystem and control lake eutrophication. It not only affects the composition and distribution of the fish, the plankton, the zoobenthos in the water, but also can reduce wave and purifying water quality.Based on the investigation and analysis of aquatic plant community distribution pattern of common shallow lakes in Anhui province,10 aquatic plants were choosed as tool species to reconstruction the ecosystem of mining subsidence wetland in Panji coal mine induced subsided zone, Huainan city. They were Zizania latifolia, Nymphoides peltatum, Vallisneria natans, Potamogeton crispus, Hydrocharis dubia, Potamogeton malaianus, Myriophyllum verticillatum, Ceratophyllum demersum, Hydrilla verticillata, and Najas marina. In study area Vallisneria natans as the dominant species, emergent plants, floating plants and other submerged plant as a patchy distribution in horizontal structure.There are obvious characteristics of the high dynamic, high ground-water level and ecological frangibility of the coal mine induced subsided zone. To explorer the biological characteristics and competition mechanism is of vital importance in such artificially constructed aquatic plant community of Panji, Huainan city. It forms scientific basis for restoration of aquatic vegetation in coal mine induced subsided wetland. This study takes the dominant species of allisneria natans as an example by means of combined methods of field survey and quadrat. It forms scientific guidance for repair the ecological environment, restoration aquatic vegetation and scientific management of coal mine subsided wetland.It is helpful for artificially constructed aquatic plant community maintaining stability and provide stably and efficiently primary producer for ecological fishery. It can keep species diversity and give full play to ecological service of coal mine induced subsided wetland.After restruction a total of 69 species (31 families,49 genera) of vascular plants belonging to dicotyledon (22 families,37 genera,41 species) and monocotyledon (9 families,25 genera,28 species), were identified in the research area. The hygrophyte community were dominated by Ass. Cynodon dactylon+Conyza Canadensis and was accompanied by Leptochloa chinensis and Panicum bisulcatum. The emerged plants community were dominated by Ass. Zizania latifolia+Typha angustifolia and was accompanied by Sagittaria latifolia and Phragmites australis. The floating plants community were dominated by Ass. Nymphoides peltatum and was accompanied by Hydrocharis dubia and Lemna minor. The Submerged plants community were dominated by Ass. Vallisneria natans and was accompanied by Utricularia aurea, Myriophyllum verticillatum, Potamogeton malaianus, and Potamogeton crispus.The results show that Vallisneria natans of subsidence district have same biological characteristics consistent with shallow lakes, such as:reproductive pattern, pollination mechanism and life history. In study area sexual reproduction is the dominant reproduction way for Vallisneria natans. Vallisneria natans can grow with current-year T. angustifolia community, while at a competitive disadvantage with at least 2 years T. angustifolia community. When T. angustifolia community coverage reached 90% Vallisneria natans community gradually disappear. Vallisneria natans competition with floating plant Nymphoides peltatum and Marsilea quadrifolia at a competitive disadvantage. The coverage, height and biomass of Vallisneria natans decreased significantly. Vallisneria natans competition with Potamogeton malaianus at a competitive disadvantage while the interspecies competition with Vallisneria natans, Hydrilla verticillata, Myriophyllum verticillatum, Ceratophyllum demersum and Najas marina is not strong, they can grow well in study area. In short, Vallisneria natans have obvious competition advantages at the aquatic plant community in identical water layer with similar growth form, while competition with different growth form, especially emerged plants and floating plants at a competitive disadvantage. Aquatic economic animals have obvious effects on the aquatic plant community.When the density of Eriocheir sinensis were 200 peace per mu, the species diversity and community stability of the aquatic plant communities in the experimentation area can be maintained, and the balance between the ecological benefit and economic benefit were also realized.