| As an important part of the natural ecological system,the nature reserves are rich in biological resources and important habitats of species.However,the rapid development of urbanization has caused the nature reserves to be eroded and destroyed,the integrity of nature reserves has been damaged,the fragmentation has been being more and more serious,and the biological diversity has been decreasing.Construction of ecological network can effectively connect fragmented nature reserves,promote biological migration and exchange,and provide space for the protection of species.Fujian province is located in the eastern coastal areas of China where land resources are limited,and has low total population.Also,its economic development is at a very high level.The adverse effect of human activities on ecological environment is extremely significant.There are many natural reserves in Fujian province,but the nature reserves distribute asymmetry on spatial scale.So it is necessary to construct the ecological network of nature reserves in to promote the sustainable development of ecological system in Fujian province.Based on landscape ecology,Heterogeneous population theory and island biogeography theory,the text uses landscape pattern index to analysis structural characteristics of different land use types of Fujian Province,and evaluate the current situation of ecological connectivity network and nature reserves using connectivity index(including the integral index of connectivity and probability of connectivity).According to the results,the nature reserves were firstly selected,the landscape cost value and the resistance surface of different landscape types were determined and generated with the help of Arc GIS.Secondly,this paper uses a minimum cumulative resistance model to constructed nature reserves potential ecological corridors,and the connectivity of potential corridors were analyzed and compared to the connectivity of current ecological network.Based on the gravity model,thirdly,the important ecological corridors were extracted.Finally,the ecological network optimization measures were proposed.Research results show that:(1)The patch density of different land types in Fujian province was relatively small,the patch aggregation degree was relatively low,and the level of landscape fragmentation was high.(2)The forest land,grassland and wetland constitute the important landscape types of potential corridors.Among them,the forest land area was largest,16621.7hm2,which occupies 86.16%of the total corridor area.(3)The level of current connectivity of Fujian province nature reserves is relatively low,and after constructing ecological network,the connectivity has been significantly improved.The overall connectivity index(ⅡC)increased from 0.0484-0.1993 to 0.3976-0.0473,and the possible connectivity index(PC)from the original 0.3976-0.2351 to 0.6890-0.1993 after building ecological network.(4)Based on the determination of ecological source and resistance surface,741 potential ecological corridors of 39 ecological sources were simulated by using the minimum cost distance model.And the gravity model was used to calculate the interaction intensity between 39 ecological sources,and the corridors with interaction force greater than 1000 were extracted,and 90 important ecological corridors were obtained.(5)The importance of large area of habitat patches is relatively high in the network,and the larger area,the higher degree of importance.(6)The interaction strength between different patches varies,which can be up to 611411.5,but the minimum is only 3.39.And the greater interaction force,the higher importance of corridor in the ecological network.The research results can provide scientific reference and basis for the protection of biodiversity in Fujian province. |
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