| Land is the carrier of most natural resources,and it is also an important natural resource.There is a direct link between land cover and ecosystem.At present,the management system of natural resources assets in China is undergoing a fundamental change.China's spatial planning system is also undergoing a transformation.The original spatial planning scattered in various departments and industries is integrated into the newly established natural resources department,and the unified planning and management of land space is implemented.Under the background of great changes in land spatial planning system,the study is of significance in ecological effects of land cover evolution and construct regional ecological security pattern from the perspective of natural ecosystem protection.On the one hand,this paper analysed the ecological effects of urban construction changing the land cover,and put forward measures to mitigate the impact;on the other hand,the researcher identify and rank the important areas that need to be protected,and put forward the strategies of follow-up ecological protection to provide basis and support for the compilation of land and space planning.This paper analysed the macro pattern of protection and development in Hunan Province,and used land cover data to analyze the evolution trend of ecological security pattern in Hunan Province in the past period.On this basis,the ecosystem service functions of water conservation,biodiversity conservation and groundwater regulation in Hunan Province are comprehensively evaluated.Based on the evaluation,this paper introduced the theory of ecosystem connectivity,identified the important ecological sources and ecological corridors in Hunan Province,and put forward suggestions on the construction of ecological security pattern in Hunan Province according to the idea of "source-corridor-node-path".The main work and conclusions are showed as follow:(1)Hunan Province is located in the middle reaches of the Yangtze River.In the protection and development strategy of the Yangtze River system,the strategy of "one belt,one department" is the strategic orientation of Hunan's development.Hunan Province has played an important role in undertaking indu strial transfer and communication between east and west areas.Dongting Lake is one of the twin kidneys of the Yangtze River.It plays an important role in biodiversity conservation and flood storage in the Yangtze River Basin.All the four rivers in Hunan Province belong to the Dongting Lake Basin and play an indispensable role in water conservation and soil and water conservation.Hunan Province is a key strategic zone in the Yangtze River Economic Zone,which is of great significance to the study of the ecological security pattern of Hunan Province.(2)Hunan Province is in the stage of rapid urbanization.In the past 20 years,the urban population of Hunan Province has increased by 23.69 million people and the urban land use has increased by 1839.14 square kilometers.Population urbanization drives land urbanization,which has significantly changed the surface coverage of Hunan Province,and also has a far-reaching impact on the ecological security pattern of Hunan Province.It is preliminarily estimated that there will still be about 15 million urban population growth in Hunan in the future,and the impact of urbanization on the ecological security pattern of Hunan Province will be in-depth.Landscape pattern analysis results showed that human activities have significantly changed the structure and pattern of regional ecosystem,and have a more significant impact on some regions,especially those with strong urbanization intensity.The specific manifestation is that natural patches are gradually fragmented by human activities,the area of artificial landscape is significantly increased,the overall landscape system becomes complex and diverse,and the natural landscape and artificial landscape are interrelated.Areas where human activities affect natural ecosystems are increasing significantly.This process has a negative impact on the natural ecosystem and needs to be focused on.The results of habitat quality analysis based on InVEST module showed that,the habitat quality is relatively good,because of Hunan Province is vast and located in the south-central region of the same period of rain and heat.Urbanization has a significant impact on the area of 2700 square kilometers in Hunan Province,resulting in a significant decline in habitat,and the proporti on of the significantly affected areas in the total area of Hunan Province has reached 1.27%.The higher the intensity of urbanization and the faster the construction of infrastructure,especially transportation infrastructure,the greater the decline of h abitat quality.(3)This study collected a large amount of basic data.Supported by large data,the ecosystem service function of Hunan Province was evaluated by NPP,model method and InVEST method.The evaluation results showed that the proportion of the most important areas,the important areas,the medium-important areas,the more important areas and the general important areas of water conservation in Hunan Province have reached 19.20%,43.87%,1.30%,28.41% and 7.22%,respectively.The proportions of biodiversity conservation areas in Hunan Province have reached 57.29%,20.07%,18.13%,3.93% and 0.58%,respectively.The proportion of the most important areas,the important areas,the medium-important areas,the more important areas and the general important areas of ecological functions of soil and water conservation in Hunan Province have reached 16.57%,24.42%,29.09%,18.20% and 11.71%,respectively.The overall pattern of ecological security in Hunan Province is "one lake,three mountains and four rivers".The assessment results of water conservation,biodiversity conservation and ecological functions of soil and water conservation are generally consistent with the pattern of ecological security in one lake,three mountains and four rivers.(4)The ecological source is the core area of ecosystem protection.On the basis of ecological assessment,considering landscape connectivity and habitat quality comprehensively,the ecological source of Hunan Province was identified,and compared with the optimization algorithm of protected area based on simulated annealing algorithm to ensure that the recognition results are scientific and reasonable.The results showed that the total area of important ecological sources in Hunan Province is 59,400 square kilometers,accounting for 28.04% of the total land area of Hunan Province,and the ecological sources mainly distribute in the northwest and southeast of Hunan Province.There are large forest areas such as Wuling Mountains,Xuefeng Mountains,Nanling Mountains,Yuechengling Mountains,Hengshan Mountains and Yangming Mountains in Hunan Province are important ecological sources.Wetland such as Dongting Lake also have important ecological functions and belong to the category of ecological sources.(5)Ecological corridor is the key area of ecosystem protection area.Based on the idea and method of ecological connectivity analysis,landscape resistance surface was constructed to simulate species migration in landscape and identified potential migration corridors.The results showed that there are 85 potential migration corridors exist in 47 important ecological sources in Hunan Province.In the central and western areas of Hunan Province,due to the scattered sources,landscape fragmentation is more serious,and ecological corridors are relatively distributed in this part of the region,and the length of corridors is relatively large;while in the southern Nanling,Yuechengling and northwest Wuling Mountains,the source areas are relatively complete,the distance between source patches is not far,species migration channels are smooth,ecological corridors are relatively small,and the length of corridors is relatively short.(6)On the basis of 47 important ecological sources and 85 important ecological corridors in Hunan Province,the ecological security pattern of the province is further analyzed,and the important ecological nodes and key radiation channels are identified.Considering connectivity,the paper evaluated the importance of source,corridor and node.The results showed that there are 18 important ecological sources,26 important corridors and 40 important ecological nodes in Hunan Province.Based on the results of the analysis of ecological source,corridor,radiation channel and node,and combined with the importance analysis of corridor node,the ecological security pattern was constructed.The pattern of ecological security is the key area of ecological protection and restoration in Hunan Province. |
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