基于源地综合识别与多尺度嵌套的徐州生态网络构建

传统生态网络构建时,生态源地的辨识多考虑生境斑块的质量和面积,较少考虑斑块生态系统服务功能与空间结构的影响;且多从一个尺度在相对封闭的系统单元内进行网络构建,缺乏尺度间的嵌套协调,易导致其结构性错位。通过构建“属性—功能—结构”三位一体的源地综合识别指标体系,基于最小费用路径、电路理论、移动窗口搜索法等方法,构建并叠置分析徐州都市区和主城区两个尺度的生态网络,并提出优化策略。结果表明：（1）两尺度生态源地重合面积79.85 km²,廊道重合长度158.42 km,重合面积45.68 km²,重叠区域对多尺度生态网络衔接稳定至关重要,需重点保护;对都市区至关重要却缺乏主城区下垫面支撑的8条廊道要优先修复。（2）识别都市区与主城区夹点分别为17处与18处,重合10处;障碍点8处与10处,重合5处。生物迁移关键区域高迁移阻力与大优化潜力并存,亟需优先修复。生物过程跨尺度的连续性要求采用多尺度级联框架协同应对生态问题。（3）基于“斑块—廊道—基质”理论从“点—线—面”三个角度提出徐州多尺度嵌套生态网络的优化策略。研究结果可为区域生态安全格局构建、国土综合整治与生态系统修复提供决策参考。

Construction of Xuzhou ecological network based on comprehensive sources identification and multi-scale nesting

The identification of ecological source in the traditional ecological network construction mostly considers the quality and area of habitat patches, but seldom considers the impact of ecosystem service function and spatial structure. Moreover, the traditional ecological network is mostly constructed in a relatively closed unit with only one scale, lacking nesting coordination, which will lead to the dislocation of ecological network structure between scales. To solve the above problems, an "Attribution-Function-Structure" index system is constructed to identify the ecological sources comprehensively. The Least-cost path method, the Circuit Theory and the Cyclic Window Search Method are adopted to form and identify ecological corridors, pinch points and barrier points respectively. From the Xuzhou metropolitan area and main urban area, two-scale ecological networks are constructed and overlapped to analyze its nested structure and coordination degree. The results showed that: (1) The coincident source areas at two scales is 79.85 km², the overlapping corridors length is 158.42 km, and overlapping corridors area is 45.68 km², which are important for the stability of the multi-scale ecological network connection and need to be protected. Meanwhile, 8 corridors that are vital to the metropolitan area but lack the underbelly support within the main urban area should be repaired as a priority. (2) A total of 17 and 18 pinch points are identified in the metropolitan area and the main urban area respectively, 10 of which overlapped; 8 and 10 barrier points are identified respectively as well, 5 of which overlapped. Contact ratio indicates that high migration resistance and large optimization potential coexist in key biological migration areas, which is in urgent need of repair. And the continuity of biological processes across scales need a multi-scale cascade framework to solve ecological problems coordinately. (3) Based on the theory of "Patch-Corridor-Matrix", a multi-scale nested ecological network optimization strategy is proposed from the three points about "Point-Line-Polygon". The research results can provide references for the regional ecological security pattern construction, land consolidation and ecosystem restoration.