| As the speed of the economic development and urbanization construction in Shengjin Lake were accelerating in recent years, the environment problems had been emerged out. mainly including flood and waterlogging disasters, water pollution, soil erosion,biological species decreasing, etc al. Soli erosion was particularly serious, and had become the primary environmental problems in Shengjin Lake, which was coursed by the number of vegetation dropped sharply. The vegetation is theme of terrestrial ecosystem, Which has an important role, such as soil and water conservation, regulating the global carbon balance, slowing down the rising gas concentration, maintain stability of global gas. Birds are mainly biological species, they are an important part of the natural ecological system, in a certain area of bird composition were investigated, which will contribute to the understanding of the ecosystem changes the environmental problems. Therefore, analyzing vegetation coverage temporal variation characteristic, revealing its dynamic change rule, researching on species diversity and diversity pattern of birds, carrying on protection on species diversity, these work can provide a basis for decision-making for ecological construction and sustainable development of the Shengjin Lake nature reserve. Vegetation cover changes in Shengjin lake wetland reserve from 2000 to 2010 year were analyzed by using SPOT NDVI data. Maximum value composites, mean value analysis and linear regression analysis were used to characterize the vegetation cover change in Shengjin lake wetland reserve..Two phrases ofTM remote sensing images of 2000 and 2010 are used to do information extraction and classification of wetland using erdas and arcgis software. The possible factors that affected the distribution and dynamics of waterfowl were discussed, along with dynamics of waterfowl habitats, the possible approaches were proposed to restore waterfowl community. The main conclusions for this research as below:(1) Month average value of NDVI in study area from 2000 to 2010 year the showed the following characteristics:NDVI values showed firstly increased then decreased from January to December, and NDVI values was higher from April to September; NDVI maintained an clearly increasing trend during 11 years, suggesting that the vegetation coverage was improved in the region.(2) The spatial distribution of NDVI had obvious regional differences in different seasons of the Shengjin Lake wetland, the distribution pattern of vegetation coverage showed mountain high and plain low. The largest NDVI value in summer, lowest in spring, with evident seasonal variation, consistent with the biological characteristics and change of vegetation. NDVI change of different vegetation types are not same, the annual NDVI value were all on the rise; grassland was generally lower than cultivated land and woodland, the beach in fluctuation have small increase, the swamp fluctuation range is the biggest.(3) The Shengjin Lake wetland vegetation cover areas the biggest during the period from 2000 to 2010 year. The experimental area had best condition, better vegetation cover buffer; The key protection of the core area of regional vegetation coverage is low; Serious degradation region accounted for the total area of 0.96%, mainly concentrated in southeast experimental area, basically unchanged area accounted for 3.94%, mainly concentrated in the urban areas; slight improvement and moderate improvement area accounted for 12.92% and 17.40% respectively, mainly concentrated in the plain area; Significant improvement area accounted for 61.18%, mainly concentrated in the core area and the experimental area.(4) The bird habitat types were interpreted using the satellite images of 2000 and 2010 year, in the past 11 years the birds habitat types changed obviously, and water, mud beach, marsh land, woodland and paddy area decreased continuously, reed beach, dry farmland and residential area increased; The retain water was the highest, the lowest rate of retention of marsh, marsh is the dominant species of the Shengjin Lake overwintering foraging and habitat, this trend will affect the distribution of these birds.(5) The four times survey of birds in the whole lake range, show the main waterfowl groups were Anatidae birds; and Little Swan, swan goose found significantly reduced, bean, white spoonbill increased significantly, so the Shengjin Lake bird diversity overall downward trend. Due to the heterogeneity in habitat, so the winter bird distribution in time and space were different. The factors affecting the dynamic change in the distribution of birds is mainly the weather, water, food and human activities. |
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