Ecological Network Planning Method And Case Study

Along with the process of urbanization,the development of natural and the reconstruction strengthen the changes in the city pattern.Habitat fragmentation and habitat loss are widely recognized as major threats to biodiversity & extinction on a global scale.The main reason is it may cause the reduction of the number of species and mortality and reduce species possibility of reproduction in other habitat.As a result of fragmentation,landscape plaques become smaller and smaller,more isolated and boundary,more or less is surrounded by unfavorable matrix.Through the ecological corridor to connect the habitat island,especially larger habitat,can reduce even eliminate the landscape fragmentation impacts on biodiversity.So constructing ecological networks and connecting the patches of spatial distribution is the effective way to protect wildlife.Existing ecology network planning methods more attention of nodes,connection and plants,these methods in solving problems in a single problem are very useful. However,these methods are less likely to find a regional scale of ecological network planning method.In this paper,integrated the research advanced experience both at home and abroad to put forward a comprehensive ecological network planning method.The major steps for ecological networks construction discussed in this paper are: (1) habitat resources assessment;(2) wildlife assessment;(3) Node chooses;(4) network analysis;(5) cost analysis;(6) least-cost analysis.The construction of ecological networks is discussed in this paper mainly adopts the method of gravity model,the resistance model and least cost model.(1) In the gravity model by the method of evaluating the gravitational attraction of each node degree solved the problems of the importance of the corridor and which nodes are connected.(2) In the resistance model through analysis of the actual path through the landscape in each land use to determine each landuse's resistance value,resolve the problem of the relative resistance it is difficulted to determine.(3) At the least cost model the first two model analysis results is used to find a minimum cost between the nodes, resolve the spatial location of the corridor it is difficult to determine and reduce the problem of building cost.The advantages of this method is(1) gives the quantitative method of selecting the node;(2) gives the quantitative method of assessment importance of the corridor;(3) gives the quantitative method of assessment importance of the network connectivity;(4) gives the quantitative method of Corridor construction;(5) maximize the use of existing green space,wetlands resources,which can lower construction costs.Based on this method,this paper chooses Chongming Island as the case study. Chongming Island located in the northeast of Shanghai,water clean and flat and with a good ecological environment.The eastern part of the beach is the red-crowned cranes,swans and other rare habitats of migratory birds.Chongming Island,the geographical environment is very suitable for plant growth,but also there have been many large wild animals,however,since the last half century,as population growth, urban construction,and gradually changed the structure of natural ecosystems, landscape fragmentation serious.The main habitat types in Chongming Island including urban,agricultural land,plantation land,wetlands.Large-scale green patch mainly located in the eastern,western and Dongping National Forest Park.These habitats uneven distributed,separated by matrix between the green patch.The lack of contact is not conducive to the proliferation and the protection of animals.Therefore, this paper chooses two kinds of resource:Woodland and wetland,to construct ecological network system with different form corridor.The research result indicates that this method is effective.For the ecological and strategic resources can be fully utilize,more than 50%of the green corridor in the planning is existing resources, construction cost is low feasible,the cost of the construction is low and feasible.The innovation of this article is:(1) extract the advantages of Gravity model, Resistance model,Least cost model and uantify the ecological networks construction Methods;(2)With GIS,given the spatial location of corridor;(3)Maximize use of existing green space,wetland resources,to reduce the cost of building.The inadequacies of this paper is the only goal is to protect the animals.The future combination of cultural,aesthetic,human demand for open space to study the network planning.