Research On The Construction Of Ecological Network In Guangzhou City With Protected Areas As The Main Region

Under the background of national ecological security development strategy,how to construct regional ecological network with protected areas and ecological corridor as key elements has become an urgent academic and practical problem in the construction of natural protection system in China.In order to lay a theoretical and practical foundation for regional ecological security and biodiversity conservation,this paper studies the construction path of regional ecological network under the system of nature reserves from the perspective of strengthening the ecological connection among patch of protected areas.This paper defines relevant concepts such as protected areas,ecological resource patches,and ecological networks.Based on an analysis of data on the spatial distribution,types,levels,and areas of protected areas in Guangzhou,the study uses the land use and landscape pattern analysis method to study the spatiotemporal changes of the ecological landscape pattern in the Guangzhou area.The paper uses the Invest model and geographic information data processing methods to identify ecological resource patches by combining protected area patches with comprehensive ecosystem service functions.The paper constructs a comprehensive ecological resistance surface based on the analytic hierarchy process,and then uses a circuit theory model to identify ecological corridors,ecological pinchpoint,and barrier areas.Based on this,the paper constructs a Guangzhou ecological network that centers around protected areas and proposes strategies for the construction and protection of various ecological elements.The main research conclusions are as follows:(1)During the period from 2000 to 2020,the primary land use types in the study area were cropland and forestland.The primary mode of land use change was the conversion of cropland to other uses and the conversion of artificial land to cropland.With the advancement of urbanization,the degree of landscape fragmentation in the study area has been significantly increasing,leading to the gradual encroachment of natural ecological spaces.Large-scale ecological patches have become fragmented into smaller patches,resulting in weakened ecological connectivity among patches.This trend has imposed enormous pressure on the protection of biodiversity and ecological security in the study area.(2)The research area was analyzed to identify 52 ecological resource patches,which exhibit significant variation in their areas.The total area of these patches is 1450.01 km~2,with protected areas accounting for 76.42% of the total area and serving as the main component of the ecological resource patches.Large-scale ecological resource patches are mainly distributed in the northern part of the research area,while small and medium-sized patches are primarily located in the central and southern regions.A comprehensive ecological resistance surface was constructed based on the Analytic Hierarchy Process(AHP)method,incorporating various dimensions of human activities.Overall,the resistance value exhibits a distribution trend with higher values in the central and southern regions and lower values in the northern area.In total,115 minimum cost distance ecological corridors were identified in the research area,with a total length of 900.56 km and an average length of 7.83 km.The distribution of these corridors is relatively balanced,and their lengths and relative resistance values vary.Analysis of the ecological corridor buffer zones suggests that the optimal width for the ecological corridors in the study area is between 100-200 m.(3)There are 11 important ecological patches in the study area,with a total area of 992.52km~2,accounting for 68.45% of the total area of ecological patches,and 41 general ecological patches,with a total area of 457.50 km~2,accounting for 31.55% of the total area of ecological patches.There are 35 important ecological corridors,with a total length of 127.37 km,and 80 general ecological corridors,with a total length of 773.19 km.Based on the ecological corridors,72 pinchpoints and 81 barrier areas were identified,with a total area of 17.57 km~2 and 35.9 km~2,respectively.Graph-based evaluations show that the closure degree(α)of the ecological network is 0.65,the edge-node ratio index(β)is 2.21,and the connectivity index(γ)is 0.77,indicating that the overall structure of the ecological network is reasonable and wellconnected.Regarding the construction and protection of the ecological network,strategies such as incorporating ecological redline management,establishing ecological buffer zones,and formulating conservation and restoration measures should be implemented for ecological patches.For ecological corridors,priority should be given to the construction and strict protection of important ecological corridors,improving the connectivity of ecological corridors,and strengthening the construction of stepping-stone areas.As for pinchpoints and barrier areas,different protection and restoration measures should be taken based on their locations,with a focus on protecting key nodes in the ecological network and unblocking areas with obstacles in the ecological network.This paper employs quantitative analysis as the primary research method to explore the regional ecological network construction path with protected area patches and ecological corridors as key elements.It proposes an ecological network construction and protection model centered on protected areas,which expands and improves the ideas and methods of ecological network construction under the protected area system.The research perspective and methods demonstrate certain innovative characteristics.