| With the in-depth promotion of industrialization and urbanization,the intensity and breadth of human development of territorial space are gradually increasing.At the same time as rapid economic growth,environmental protection is facing great pressure,which greatly affects the sustainable use and management of national space.In 2012,the 18th CPC National Congress for the first time included ecological progress in the five-area overall plan to solve the problem of balancing economic development with ecological protection.Since then,ecological quality has continued to improve and ecological service functions have steadily improved.However,urban sprawl,rapid population growth,prominent land use conflicts and a series of social problems persist for a long time.Positive interaction between the protection and development of natural ecosystems and social and economic systems has not been achieved,regional ecological problems have yet to be solved,and ecological protection and restoration remains an insurmountable proposition for high-quality national and regional development.The ecological protection and restoration of territorial space is from the perspective of zoning classification and management.Through zoning regulations,human activities are directed and restricted,and important ecological areas are protected and restored.Exploring the theories and methods of zoning and management of territorial ecological protection and restoration,analyzing regional ecological problems,and putting forward targeted management measures are conducive to scientifically and reasonably grasping the development direction and realizing the ecological governance of territorial space and regional sustainable development.Coastal areas are places where land and sea interact directly and intensely.They have rich ecosystem types,but a developed economy,dense population,high-intensity territorial development and fragile ecological environment.The interaction between human activities and the ecological environment has attracted widespread attention from all walks of life.However,at present,research on the theory and method of ecological protection and restoration zoning of coastal urban territorial space is still lacking.How to construct an ecological environment assessment framework that takes into account both land space and sea space of coastal cities,analyze regional ecological environmental problems,form a systematic system of zoning methods for ecological protection and restoration of coastal city territorial space,and propose differentiated management strategies?It is of great significance to promote the ecological governance of land space,guide relevant departments to formulate effective ecological protection policies,and guarantee the steady development of China’s social economy.Based on system theory,landscape ecology theory and restoration ecology theory,and taking Qinzhou City of Guangxi as the research object,this thesis constructs a comprehensive assessment framework for the ecological environment of land space and sea space respectively,explores the characteristics of the ecological environment of land space and sea space,and uses the GWR model to analyze the factors affecting the ecological environment of territorial space.According to the microstructure characteristics of the ecosystem in Qinzhou City,the ecological network structure of Qinzhou City was identified,and the problems existing in the ecological environment of Qinzhou City and related regions were further discussed.On the basis of the above,the thesis puts forward the idea of zoning for territorial ecological protection and restoration in Qinzhou City,and constructs a whole set of zoning method systems that focuses on the overall evaluation and internal function balance of the ecosystem,coordinates the land space and sea space,and gives consideration to the structural characteristics of ecological networks.On this basis,the zoning research is carried out,the rationality of the zoning is analyzed,and the characteristics and functional positioning of different zones are analyzed.Finally,differentiated management schemes are proposed from the dimensions of integrated management and vertical management.Key findings include the following:(1)From the point of view of the spatial and ecological environment characteristics of Qinzhou City,the overall ecosystem service functions such as water conservation,soil conservation,biodiversity and carbon storage in Qinzhou City showed an upward trend on the time scale,and the ecological sensitivity of the low sensitive area gradually increased,while the high sensitive area decreased significantly.From the perspective of spatial distribution,the spatial heterogeneity of ecosystem service functions is obvious,and the ecologically sensitive and highly sensitive areas are mainly along the Qinjiang River from Qinzhou City to Lingshan County.From the perspective of topographic gradient effect,ecosystem services showed an overall upward trend with increases in elevation and slope.According to the spatial correlation characteristics,the ecosystem service hotspots were concentrated in the eastern and western parts of Qinzhou City,and the distribution of ecological sensitivity hotspots was opposite.In terms of spatial assessment of sea area,all coastal protection functions are located in the administrative area of Qinnan District.Maowei Sea has the highest level of marine biodiversity,and the carbon storage level of the sea area mainly exhibits a Mosaic distribution.The carbon storage level of the paddy field landscape is high,but the distribution is relatively fragmented.In terms of influencing factors,the spatial heterogeneity of the impact of temperature and precipitation on the ecological environment of Qinzhou City is obvious.Elevation has a positive impact on the ecological environment,while human activities have a negative impact on the ecological environment.Especially in the central part of Qinzhou City,the valley area along the Qinjiang River Basin and the main urban area of Qinzhou City,the intensity of human activities is strong and the impact on the ecological environment is severe.(2)From the perspective of the spatial ecological network structure of Qinzhou City,a total of 36 ecological sources with a total area of 2,494.79 km~2 were identified,73 ecological corridors with a total length of 1,400.50 km were extracted,86 ecological nodes with a total length of 114.70 km were extracted,and the area of ecological obstacle points totalled 15.31 km~2.From the perspective of spatial distribution,the ecological source patches distributed in the north and west of Qinzhou City were small and scattered,while the ecological source patches in the east and south were larger.Overall,the ecological resistance value of Qinzhou City is low,and the high value areas are scattered,showing a relatively obvious distribution of agglomeration within the scope of construction land in Qinzhou City.The ecological corridors in Qinzhou City are relatively short and concentrated,effectively connecting the source patches in the east and the middle,and part of the ecological corridors run through the Qinzhou sea area.The ecological nodes in Qinbei District are scattered and abundant,mainly because human activities in Qinbei District are strong.Lingshan County connects Qinzhou City from east to west,and its ecological node restoration is related to the overall construction of an ecological network.Some ecological barriers are located at the junction of ecological source patch and ecological corridor,which is the key position to connect the ecological source patch and corridor.The protection and restoration of ecological barrier areas are of great significance to the connectivity and integral function of ecosystems.(3)From the perspective of the territorial ecological protection and restoration zoning of Qinzhou City,in order to propose a zoning plan for specific problems and unique characteristics of coastal cities and form systematic zoning results,the comprehensive zoning idea coupled with"ecosystem service function"and"ecological network identification"and the zoning concept of"function guidance"+"network refinement"were proposed to quantify the ecosystem service weighing state.Identify the types of high tradeoff ecosystem services in different regions,integrate spatial ecological analysis of sea areas into regional decision-making,and introduce the concept of"tradeoff"to form the regional plan for coastal urban ecological restoration.Based on the zoning plan,Qinzhou ecological protection and restoration zoning will be carried out to form priority protection areas for soil conservation,priority protection areas for carbon storage,enhanced protection areas for soil conservation,improvement and promotion areas for carbon storage,improvement and promotion areas for biodiversity,and comprehensive management areas for water conservation.Based on the regional ecological network,Qinzhou City’s territorial ecological protection and restoration zoning was supplemented and improved,forming the priority area of source protection,priority area of corridor connectivity,priority area of corridor connectivity strengthening,comprehensive ecological network enhancement area and ecological network maintenance area.The zoning plan and the zoning results proposed in this study are in line with the needs of national and regional ecological environment protection and restoration,reflect the differentiated thinking of environmental protection,and conform to the principle of"protection first,comprehensive management"and the goal of"maintaining the zoning plan and the zoning results proposed in this study are reasonable and can effectively serve the ecological management and sustainable development of the national space of Qinzhou City,as they are in line with the principles of"protection first and comprehensive management"and the goals of"maintaining ecological networks and improving ecosystem service functions".(4)From the perspective of differentiated management of ecological protection and restoration of national land space in Qinzhou,the priority protection zone for soil conservation should strengthen the implementation of regional soil conservation projects and integrated management of small watersheds and other projects in the future.In the construction of Qinzhou Port Free Trade Zone and industrial parks,the relationship between human disturbance and ecological protection should be balanced,and the supervision and management of production and construction activities should be comprehensively strengthened.Carbon storage priority protection zone improves forest carbon sinks and soil carbon sinks by carrying out breeding and transformation projects and planting nitrogen fixation plants.Soil Conservation Enhancement Reserve improves soil conservation through sealing and protection and water-saving forest construction.Carbon storage improvement and enhancement zone improves carbon storage by creating urban green spaces and using low carbon construction materials.Biodiversity improvement and enhancement zones should coordinate the land and sea ecological protection red line and various marine nature reserves,strengthen marine biodiversity protection and enhance the level of protection of rare and endangered marine species.The comprehensive treatment area of water source connotation should appropriately increase the area of urban green space coverage,promote the model of mixed planting of various tree species,and increase the area of water source connotation forest.In addition,the study matches the policy intensity of the zoning districts in three dimensions:natural restoration,restoration and protection,and comprehensive management,in which soil conservation priority protection zone,carbon storage priority protection zone,and soil conservation enhancement protection zone are based on natural restoration and restoration and protection;carbon storage improvement and enhancement zone,biodiversity improvement and enhancement zone,and water source connotation comprehensive management zone are based on comprehensive management;source land protection priority zone and corridor.The source protection priority area and corridor connection priority area are mainly natural restoration and restoration protection,and the corridor connection enhancement area and comprehensive ecological network improvement area are mainly comprehensive treatment.In view of the high trade-off status and large area distribution of both soil conservation and biodiversity in Qinzhou,this study proposes a management strategy from the perspective of vertical management.Areas below 250 m elevation and with slopes of 5 degrees or less are soil conservation and biodiversity remediation areas,and ecological projects such as ecological fallow will be implemented in the future to enhance the level of intensive use of construction land,further optimize the ecological network structure,and strengthen the ecological network structure.The level of connectivity of patches and the construction of ecological corridors.250 m-650 m elevation and the area with slopes between 5 degrees and 23 degrees are soil conservation and biodiversity conservation areas.The area above 650 meters and a slope of 23 degrees is the area for soil conservation and biodiversity restoration.In the future,nature reserves should be established for vegetation restoration and forest sealing to improve soil conservation and species abundance.The innovation of this thesis is mainly reflected in the following three aspects:(1)Building a comprehensive evaluation system for the ecological environment of coastal cities’national territory from a"multidimensional and multi-perspective"approach effectively enhances the integration of the"land-sea coordination"research.Based on the theoretical analysis of the ecological environment characteristics of coastal cities and the special significance of national territory ecological protection and restoration,this study organically integrates the evaluation framework of land-based spatial ecological environment from the perspective of the interaction between"human activities"and"ecological environment"and the evaluation framework of maritime spatial ecological environment based on the dimensions of"marine ecological security"and"marine ecosystem services".The study systematically proposes a"multidimensional and multi-perspective"comprehensive evaluation system for the ecological environment of national territory,actively responding to the needs of comprehensive evaluation of the ecological environment of coastal cities’national territory,and providing theoretical support and practical solutions for the governance of the ecological environment of coastal cities’national territory.(2)Building a comprehensive zoning scheme for ecological protection and restoration guided by functionality,land-sea coordination,and network consideration effectively promotes the systematic research of the existing zoning.Based on the assessment of land-sea spatial ecological environment and the identification of ecological networks,this study proposes the zoning concept of"function guidance+network refinement".It comprehensively balances the ecological functional intensity and its trade-off state in land-sea spatial function at the macro level and focuses on the ecological network structure at the micro level.Finally,it constructs a comprehensive zoning scheme for national territory ecological protection and restoration that takes into account"function guidance,land-sea coordination,and network consideration".This overcomes the limitations of the single-dimensional zoning method in the past and is an innovative attempt to the existing system of national territory ecological protection and restoration zoning.(3)This study extends the existing research framework of ecological protection and restoration zoning,proposes a differentiated control viewpoint,and expands the research vision of existing ecological protection and restoration zoning.Existing research on ecological protection and restoration zoning focuses more on exploring basic evaluation and research methods,and some of the policy recommendations proposed also lack strong targeting,which is not conducive to the support of zoning research results for practical needs,and may cut off the organic connection between theoretical research and practical needs.Based on systematic zoning,this study proposes detailed differentiated control strategies from the dimensions of comprehensive zoning and vertical zoning,constructs a policy intensity matching scheme,and effectively expands the research vision of existing ecological protection and restoration zoning. |
