The Change And Simulation Of Landscape Pattern In Yancheng Coastal Wetland Of Jiangsu Province

Wetland is unique natural geographical and ecological landscape units on the planet, with a huge resource potential and environmental function, known as the’kidney of the earth.’As an important component of wetland, the coastal wetland is of great significance for maintaining balance of regional and global ecosystems. Yancheng coastal wetland on the central coastal zone of China, which is China’s economical developed areas of the coastal zone in Jiangsu Province. The coastal wetland of Yancheng in Jiangsu province as a typical silt tidal flat is characterized by great area, entire ecotype and complex sediment deposition course in China where have founded Yancheng Red-crowned Crane National Nature Reserve. So it has rich and powerful resources and ecosystem services, but it is also eco-fragile area and sensitive environmental areas. However, because of the natural and human disturbance, the wetland original natural state subjected to strong interference, changes in composition and spatial pattern have taken place, resources and environment are deteriorated. In the context of sustainable development theory, the two aspects of structure and layout of wetland landscape pattern simulation study carried out, contributed to the coordination of nature-society-economic development, to provide a degree of reference for Yancheng related policies.Based on the research summarized changes and optimization simulation of landscape pattern in domestic and foreign papers, analysis of dynamic changes of landscape pattern through the area of transfer matrix method and the landscape pattern index; and driving forces of landscape pattern changes were discussed; through the establishment of multi-objective programming model, landscape structures in Yancheng coastal wetlands was simulated; and as a basis, cellular automata model is used to simulate the spatial distribution pattern. Paper concluded as follows:1. In the18years between1988and2006, natural wetland is declining, constructed wetland continue to rise. Shrimp ponds and cultivated area have significantly increased, by2006, accounted for nearly50%of the total area of landscape, as the advantages of the wetland landscape. Alien species spartina expansion, by the initial plaque distribution gradually evolved into a continuous band, to some extent inhibited the growth of native natural vegetations, limiting other natural cover of the sea "rolling succession" speed, and even the degradation of native ecosystems. With the increasing number of patches, wetland landscape fragmentation increased. Shannon evenness index experienced a gradual increase and then decrease, indicating that human beings constantly engaged development and utilization of the wetlands, increasing the speed and extent of development, making the proportion of various types of more uniform size and then re-widening, artificial wetlands instead of natural wetland as the dominant landscape.2. Landscape pattern in Yancheng coastal wetlands has changed under the action of the driving factors in natural and anthropogenic:climate, topography and other natural factors determines the pattern. In the larger space and time scales, the introduction of alien species spartina on the one handplayed a role in revetment and siltation, the other hand it also changes the natural succession law and has a huge impact on the local ecological environment; human factors is the main driving force for changes in landscape pattern. Population growth and economic development are an urgent need for the development and utilization of coastal wetlands. Driven by economic interests and over the blind reclamation is the main reason for changes in landscape pattern.3. By constructing a series of socio-economic and ecological-environment constraints, through the establishment of multi-objective programming model, landscape structure in Yancheng coastal wetland is optimized. The results show that:a substantial increase in cultivated area in Yancheng coastal wetland eases the pressure on farmland protection in Yancheng. A significant improvement in ecological benefits of wetlands has a positive effect on the sustainable use of land. On the basis of ecological environment, economic efficiency increases that not only protecting the local ecological environment, but also ensuring the requirements of social and economic development. It shows that structure optimization of landscape pattern in Yancheng coastal wetlands is reasonable and feasible.4. In the constraints of the number of configurations for optimization of landscape structure, use cellular automata model to simulate the spatial distribution pattern. The results show that:ecological restoration of shrimp ponds used to been developed happens near the Sheyang river. With the succession to the coast, spartina continues to be developed which is consistent with the policy of limiting its expansion. Changes of cultivated land mainly concentrated in the south of Sheyang river. The increase in cultivated area is due to shrimp ponds which have better conditions are developed and used, which is consistent with the localization about an important reserve land resources in Jiangsu province, and has played a huge role in urban development and farmland protection in Yancheng. Because of the enormous cost of the ecological environment, while spartina and other vegetation constantly are developed to shrimp ponds, shrimp ponds are also developed to cultivated land, which is consistent with the unity of economic objectives and ecological targets.