Research On Vascular Plant Resources And Ecological Protection Of Gucheng Lake Wetland

Wetland, known as the "kidney of the earth", is the most unique ecosystem and transitional landscape on the earth surface, they influence and participate in the most of the geochemical cycle process, and play a major role in the material exchange and energy flow between biosphere and non-living beings kingdom. Wetland biodiversity is extremely rich, being the most important "species gene pool" in the earth surface system, it acts central effect and leverage to maintain the overall function of terrestrial ecosystems and ecological balance of the earth, and the biodiversity also promotes the coordinated development of economy and ecology. So wetlands cannot be replaced with other ecological role in maintaining ecological balance, conservation of species diversity, improving the ecological environment, regulating climate, providing energy, water conservation, water purification systems, and so on. To this end, the authors investigated the plant resources of Gucheng lake, the largest lake in Nanjing, and based on the statistical analysis on the vascular flora composition, characteristics, and relationships of adjacent floras, specific results are as follows:1. The wild plant resources of Gucheng lake wetland has228species, belonging to66families,175genera. Among these plants, for ferns plants, there are4families,4genera,4species. For angiosperms, there are62families,171genera,224species, including dicotyledons52families132genera170species, and monocotyledons10families39genera54species.Statistics from the life form in the Gucheng lake wetland shows that there are191herb species,34woody species,3vines species. They can be used as edible plant, medicinal plant and ornamental resources, treasure and endangered plant resources, and others. The important economic plants in the local areas are Nelumbo nucifera, Trapa incisa, Typha orientalis, Phragmites australis and so on.2. For components of vascular plant flora, the proportion of large families or genera are small, with small families and genera are dominant. There are2families, to account for3.03%, has more than10genera; the number of families including5-9genera are small, accounting for9.09%; the small section families with2-4genera are the important parts of Gucheng lake wetland plants, and they account for a higher proportion; one family with only one genera is the main vascular plants component, which accounts for59.09%. Species composition displays that, the number of families with more than10species is3(4.55%). There are11families (16.67%) with5-9species, while which have a high proportion of vascular plant genera and species in Gucheng lake wetland. The number of families including2-4species is19(28.79%), but the proportion of species or genera level is lower. The number of the family with only a single species is33(50%), showing an absolute advantage, but in the species and genus level, it is relatively low,80%of single genera, have a single species. The characteristic of Gucheng lake vascular plants flora is not obvious.3. From the view of the family level about the Gucheng lake wetland plants geographical composition,66families can be divided into5type3variants. Actually here is a singleness, the usual types to been widely distributed in the world have42families, the type of tropical distribution have16families(66.67%, excluding the worldly distribution). The pan-tropical distribution pattern has an absolute advantage in the Gucheng lake wetland plants vascular flora, reflecting the pan-tropical basic of the families distribution. North temperate distribution type and its variants are the main temperate type, here are6families (25%). This distribution is an adaptation to the geographic location, reflecting the transition characteristics from tropical, subtropical changing to temperate.Followed by the genera level, Gucheng Lake vascular flora of wild plants have175genera, distributed into13floristic type9variants, the tropical genera types have58genera (47.93%), of which the pan-tropical distribution and its variants is the dominant; the number of temperate type is63(52.07%), the North Temperate and Old Continent temperate distribution is pretty higher, in other words, the temperate elements make significant dominant. This indicate the strong affinity with tropical plants while transited to temperate type characteristics.4. The research on relationship with adjacent areas plants flora shows, Gucheng Lake have a higher similarity with Hongze lake, and lower similarity with Luoma lake, and minimum similarity with Shang lake, the results indicated that the geographical position may have a relatively influence on vascular plants flora composition.5. Gucheng Lake wetland plants have the general characteristics of wetlands, these species can be divided into12major community types, mainly Hydrilla verticillata communities, Potamogeton crispus community, Potamogeton distinctus communities, Trapa incise communities, Phragmites australis communities, Polygonum orientale communities, Typha orientalis communities.6. Due to the history of cultivation, breeding, fishing and other effects of over-development, the open ecosystem of Gucheng lake is changing into a semi-closed ecological system, as the reducing capacity of bearing and handling pollutants, the biodiversity index is increasing decreased. In recent years, with the county’s economic development and water resources utilization, the eutrophication become more severe, water quality is being worse and worse, aquatic ecosystems are zteo suffering different degrees of damage. Therefore, we would protect Gucheng lake wetlands with high standards construction of protection zone, coupling the typical county’s water resources such as Gaochun lake and Gucheng lake with state-level national aquatic germplasm protected areas, and focus on the waterfront and the surrounding areas ecological unity to build a regional ecological support system based on wetland area and the surrounding organic agriculture park, in order to maintain the ecosystems of wetlands. The authors also proposed some useful measures and recommendations, such as enhancing lake management, adding funding for protected areas, strengthening publicity, implementing the right lake reclamation policies, controlling lake pollution to prevent eutrophication, and the rational use of wetlands resources scientifically.