关键词: 生态安全格局, 生态系统服务供需, 生态安全网络, 生态分区修复, InVEST模型

Abstract:

Against the backdrop of rapid global urbanization, the imbalance between the supply and demand of ecosystem services and the disruption of network connectivity pose serious challenges to the regional ecological security. Constructing an ecological security pattern (ESP) from the dual perspectives of the supply and demand status of ecosystem services and the structural characteristics of the ecological security network has significant implications for regional ecological security and ecological civilization. Existing methods for constructing ecological security patterns primarily focus on analyzing natural baseline conditions, making it difficult to coordinate the spatial matching of service supply capacity and social demand pressure with the spatial synergy of network structures. This exacerbates supply demand mismatches and network structural fragmentation, hindering the precise implementation of policies in national land space governance. Using Hunan Province as an example, this study proposes a “state-structure” dual-dimensional assessment framework for constructing ecological security patterns in the region. State Dimension: The InVEST model was used to calculate the supply of four ecosystem services: food supply, water production, carbon sequestration, and soil conservation. A socioeconomic statistical database was used to construct an ecosystem service demand assessment model. The Ecosystem Service Supply-Demand Ratio (ESDR) was introduced to characterize the supply demand status of individual services, and the Comprehensive Ecosystem Service Supply-Demand Ratio (CESDR) was used for multi-dimensional integration. The Z-score quadrant model was applied to analyze the spatial matching characteristics of ecosystem service supply-and-demand. The structural dimension is the combination of supply and demand assessment results to select high-value areas with comprehensive supply and demand ratios as potential source areas, identifying core patches through landscape form spatial pattern analysis (MSPA), and overlaying them to create an ecological source area system. Seven factors, namely elevation, slope, land use type, NDVI vegetation index, distance to water bodies, distance to roads, and population density, were identified as resistance factors, weighted using the analytic hierarchy process (AHP), and through consistency testing and sensitivity analysis, a comprehensive resistance map was generated. Based on circuit theory methods, ecological corridors, nodes, and barrier points were identified, and the ecological safety network structure was analyzed based on the “ecological source area-ecological corridor-ecological node-ecological barrier point” framework. By integrating ecosystem service supply and demand diagnosis with ecological safety network structure identification, a spatial decision-making system was established to support ecological zoning and the precise restoration. Using a cross-classification matrix and overlay analysis methods, ecosystem service supply and demand correspond to the “state dimension,” while the ecological safety network corresponds to the “structure dimension.” With state (high, medium, or low stability) as rows and structure (high, medium, or low connectivity) as columns, a nine-cell matrix was formed, with each cell corresponding to an ecological zoning with different risk levels. By integrating ecosystem service supply demand diagnosis with ecological security network structure identification, an ecological security framework was established, along with a spatial decision-making system supporting ecological zoning and precise restoration. The results indicate: 1) Hunan Province’s ecosystem service supply exhibits a “high in southwest, low in central” spatial differentiation pattern, while ecosystem service demand shows an “evenly distributed with localized peaks” spatial pattern; the comprehensive ecosystem service supply presents a “U-shaped high supply, low in central” spatial pattern, Comprehensive ecosystem service demand exhibits a spatial pattern of “scattered high demand”; the spatial pattern of comprehensive ecosystem service supply and demand is “high around the periphery and low in the central region.” Zone I (high supply, high demand) accounts for 47.51% of the total area, encompassing 40 counties and districts with a total area of km². Zone II (low supply, high demand) accounts for 0.71%, encompassing 10 counties and districts, with a total area of km². Zone III (low supply, low demand) accounts for 20.9%, encompassing 37 counties and districts, with a total area of km². Zone IV (high supply, low demand) accounts for 30.88% of the total area, encompassing 35 counties and districts, with a total area of km². 2) 38 ecological source areas were identified, covering a total area of 3.21×10⁴ km², with 43 inter-regional corridors, including 43 important ecological corridors and 44 general ecological corridors, with a total length of 4.25×10³ km. Seven important ecological nodes and 53 obstacles were identified in this study. Large-scale ecological source areas exhibited a “west-south” winged aggregation pattern, which was highly consistent with regions where pristine ecosystems, such as the Wu ling and Nan ling Mountains in Hunan Province, were well-preserved. The resistance values on the comprehensive resistance surface ranged from 0 to 6.04 (expressed as an average), and the distribution of nodes generally aligned with the spatial pattern of ecological source points, whereas ecological obstacle points were predominantly located along the edges of ecological corridors. 3) Results: The study delineated 3.27×10⁴ km² of core source areas, 1.53×10⁵ km² of ecological protection zones, 1.45×10⁵ km² of flexible regulation zones, 1.55×10³ km² of restoration and enhancement zones, and 1.98×10⁴ km² of urban development zones. Based on ecological risk grading, five categories of zones were proposed with corresponding restoration and protection strategies: Core Source Area: Implement comprehensive intelligent monitoring and strict source protection, prohibit all development activities, and strengthen remote supervision of mountain ecological core zones; Ecological Protection Area: Enforce comprehensive ecological red line protection, establish buffer zones to block human interference, and implement statutory rigid control mechanisms; Flexible Regulation Area: Establish a flexible constraint mechanism linking development intensity with the Ecological Health Index (EHI), to guide the phasing out of low-efficiency energy use and the replacement with eco-friendly industries; Urban Development Zones: Mandate the planning of natural succession restoration land, reserve strategic blank spaces to alleviate urban pressure, and support future ecological space expansion; Restoration and Enhancement Zones: Adopt an “ecological restoration-spatial replacement- functional implantation” regulatory pathway, with restoration outcomes rigidly linked to the supply of construction land indicators. A “state-structure” dual-dimensional coupled diagnostic framework was created to address the synergistic challenges of supply demand mismatch and network fragmentation. A spatial decision support system was established, spanning assessment, identification, zoning, and restoration, to achieve precise spatial adaptation of ecological protection and restoration. This technical approach provides a scalable methodological framework for constructing ecological security patterns in diverse topographic regions, such as mountainous hills, plains, and basins, and holds significant theoretical and practical value for advancing the construction of ecological civilization.

Key words: ecological security pattern, ecosystem service supply and demand, ecological security network, ecological zone restoration, InVEST model