Habitat Network Optimization Based On Spatial Region Division And Multiple-Perspective Evaluation

In recent years,the rapid development of urbanization in the Yangtze River Delta has brought a series of advantages,such as industrial concentration and economic prosperity,but there are some disadvantages at the same time,such as the rapid development of urbanization changed the land use type in the study area,taking up a lot of ecological land,it resulting in a decline in the number and quality of habitats,and impacting species’s utilizing for residual habitats,so the habitat network is badly in needs to be optimized.Habitat network optimization based on spatial region division can broaden the ecological space of the whole study case,improve the quality of the habitat and strengthen the ecological relationship between different habitats,and it also can obtain the maximum benefit of the habitat network with the lowest cost by this network optimization method,which is of great significance to the regional ecosystem health and the biological diversity protection.At present,single dimension(time or space)optimization and the single scale optimization(unified optimization standard in research area)is adopted to optimize habitat network at home and abroad.The target of optimization(habitat patches,migration corridor),the object of optimization(increasing connectivity of habitat network,increasing plaque area and enhancing ecological function of habitat network)and optimization dimension(space dimension optimization,time dimension optimization)is a main part of network optimization study.If the target,object and the dimension are different,costs and benefits of network optimization will be a great difference.There are two kinds of traditional network optimization methods:single network optimization and multiple network composite optimization.The single network optimization improving network composition elements and connectivity by repairing or adding habitat patches,habitat nodes,temporary habitats,and potential migration corridors.The multiple network optimization mainly includes the different methods optimization for single objective specie and the single method optimization for multiple objective species.And they mainly from the perspective of satisfying a set covering problem in these methods,the specific ways including composite of network component elements and identifying and restoring new habitat nodes or habitat patches using different net,Arork optimization methods,selecting the most important habitat nodes and patches based on set-cover problem,at the last,obtaining the most optimal habitat network optimization scheme.The practice shows that the two single dimension optimization method has ignored the real economy condition in the process of optimization,the protection cost and the actual situation fit is not high,the protection benefits and costs do not match,resulting in the resources waste of protection cost to a great extent,so we are urgent to explore new habitat network optimization scheme.Based on this,this paper selected the Su-Xi-Chang region of the rapid urbanization area as the study area,and we adopted the administrative division optimization method based on multidimensional perspective in process of habitat network optimization,and to discussing the problem of habitat network protection.We making spatial administrative optimization optimization and unified optimization in whole region.Aiming at the optimization results of different scenarios,we evaluated the efficiency of optimization from the multiple perspective(the constituent elements of habitat network+the network structure index＋the ecosystem function of habitat land),and in the hope of obtaining the optimal habitat network optimization scheme.In the premise of improving the regional network function and protecting the species diversity in research area,increasing the the operational possibility of optimization program,reducing the protection cost and improving the protection benefits,and providing the new ideas and reference for the construction of regional ecological network and ecological security pattern.The specific eontents are as follows:(l)The internal heterogeneity in region involves different aspects,such as politics,economy,management and the willing of different organizations.From the perspective of structure,the regional heterogeneity can be divided into quantity heterogeneity and quality heterogeneity.And the two aspects both can have important influence on the regional internal protection benefit.This paper from the perspective of geographical and space administrative differences,aiming at the intermal heterogeneity in quality in the study case,we took the protection cost as the economic heterogeneity,the later management cost as the management heterogeneity,and set the different seenarios of the spatial administrative partition optimization and the unified optimization in whole region,we putted forward a new regional network optimization scheme which have more operational performance,more efficient.It can be used to achieving the maximum ecological and economic efficiency of the target species habitat network in the study area,with a view to protecting the biodiversity and ecosystem health of the research area and taking into account the maximum economic benefits of the region.(2)On the base of the optimization results of different network optimization scenarios,we evaluating the optimization efficiency of the different optimization scheme from the multiple perspective(the constituent elements of habitat network+the network structure index+the ecosystem function of habitat land)in comprehensive,objective and scientifie evaluation methods.And it will provide more scientific and reliable reference for potential habitat network protection.The results showed that:(1)The optimization of habitat network based on the spatial administrative division:l)The number of habitat patches,the number of migratory corridors and the total patch area of research region both presented a downward trend in 2015,the degree of habitat fragmentation was increased,and the habitat network optimization was urgCent to be optimization;2)The optimization costs and area of different administrative region were different under the scenario of zoning optimization.It is closely related to local fiseal revenue and macro Policy,of which the Suzhou has the highest optimization efficiency,the Wuxi is the next,and the Changzhou is the lowest;The unified optimization in the whole area achieved only 58.65%of the optimization area,but the optimization costs is higher than spatial administrative division optimization.The optimization efficiency is far lower than the zoning optimization,and the optimal scheme is the spatial administrative division optimization.3)The average patch area,the number of new corridors and the node degree in spatial administrative division optimization are higher than the unified optimization of whole area.The optimization efficiency depends on the view that the different space administrative units are lower than the administrative differences.(2)The evaluation of habitat network optimization results based on multiple perspectives:1)In terms of network components,the number,area and importance of habitat patches in spatial administrative division optimization both are higher than the unified optimization of whole area,and the total optimized area of the habitat is about 142%for the total optimized area of unified optimization in whole area,which is far higher than the efficiency.The number of new migration corridors in spatial administrative division optimization is 80%for unified optimization;2)In terms of the network structure,whether from the angle of the whole research area or the different administrative units in the study area,the network structure index in spatial administrative division optimization is higher than unified optimization of the whole area optimization network structure,and the average height of the area optimization after the partition optimization is about 21%;3)As far as the ecosystem service function of habitat land use type is concerned,although the the ecosystem service function value of the two optimization schemes has been improved,the increase degree of spatial administrative division optimization is 21.95%,it was higher than that the whole area optimization(19.85%).And the two schemes mainly rely on improving the value of water and soil conservation and the value of waste disposal.(3)The habitat network optimization based on the concept of administrative division is different from the previous research on the habitat network optimization.It is an optimization scheme of habitat network in the unified research area at different scales,making full use of the heterogeneity of the research area in politics,economy and geography,aiming at obtaining a habitat optimization scheme which ecological and economic maxinization.The method and idea have high theoretical and practical significance for multiple-dimensional and multiple-scale in aspect of habitat network optimization.