珠三角国家森林城市群生态安全格局变化与空间优化识别

Ecological pattern change and spatial optimization identification of national forest urban agglomeration in the Pearl River Delta,China

识别生态安全格局(ESP)对于区域经济可持续发展和生态保护平衡具有重要意义。面向珠三角国家森林城市群规划建设,应用形态学空间格局分析(MSPA)、电路理论、空间设计网络分析(sDNA)等方法,通过构建珠三角森林城市群建设前后的生态廊道网络,识别了景观形态、拓扑连通性及其指示的生态格局时空演变,结合规划功能区的土地利用变化和网络连通特征,探讨了珠三角森林城市群生态安全格局空间优化的识别结果。研究结果表明:(1)2015、2020年生态景观形态变化,生态源地核心(core)类型面积和生态廊道长度占比明显增加,分别为14.97%、0.40%,生态斑块聚集与连通增加是当前生态格局变化的主要特征;(2)珠三角的东部、西部森林生态屏障和南部沿海生态防护带(两屏一带)的连通性潜力明显增加,高、中高、中低连通性的生态廊道占比分别增加2.65%、6.98%和8.25%,形成合理提升的生态网络连通结构。(3)集成生态源地重要性与生态廊道连通性、生态断裂点的优化目标,从生态点-线-面基质构建优先保护修复区识别准则,结果识别得到优先保护的重要生态源地面积为14656.06km^(2),优先修复的生态廊道有930.69km及246个断裂点,进一步为空间优化识别与安全格局提升探明路径。总体上,2020年珠三角森林城市群建设提升了“两屏一带”的生态安全格局,生态源地与网络连通性的增加揭示了城市群中心生态格局的提升和沿海防护带生态修复优化空间的识别结果,指示了加强城市群与沿海生态廊道建设的必要性,从工程修复视角为森林城市群生态安全格局识别与空间优化提供科学参考依据。

Identification of the ecological security pattern(ESP)is of great significance for the coordinated balance of regional economic sustainable development and ecological protection.This article focuses on the planning of the Pearl River Delta National Forest City Agglomeration.Methods such as Morphological Spatial Pattern Analysis(MSPA),Circuit Theory,and spatial design network analysis(sDNA)were applied to construct the development pattern of ecological networks before and after the Forest City Agglomeration construction in the Pearl River Delta.The spatiotemporal evolution of ecological landscape forms,topological connectivity,and the indicated ecological pattern were identified.Combining the land use and network connectivity characteristics of the planned functional zones,the study explored the identification of optimal spaces for the ecological security pattern in the forest city agglomeration of the Pearl River Delta.The results showed that:(1)In the change of ecological landscape morphology in 2015 and 2020,the core area and the length of ecological corridor increased significantly by 14.97%and 0.40%,respectively.The aggregation and connectivity of ecological patches are the main characteristics of the current ecological pattern change.(2)The connectivity potential of ecological barriers in the western and eastern forests and nature reserves,as well as the ecological protection belt along the southern coast(referred to as“two barriers and one belt”),has significantly increased.The proportions of highly connected,moderately-highly connected,and moderately-low connected ecological network structures have increased by 2.65%,6.98%,and 8.25%,respectively,forming a reasonably improved ecological network connectivity structure.(3)Integrated the optimization targets of ecological source importance,ecological corridor connectivity and break points,to build priority protection and restoration of the identification criteria,we identified priority protection of important ecological source area for 14656.06 km^(2),priority repair of ecological corridor with 930.69 km and 246 break points,further for exploring the path for spatial optimization identification and security pattern improvement.Overall,the forest city agglomeration in the Pearl River Delta formed an improved ecological security pattern with the“two barriers and one belt”in 2020.Ecological sources and the increase of network connectivity revealed the center of urban agglomeration ecological pattern improvement and the identification results of the ecological optimization space in the coastal protective belt.It indicates the necessity of strengthening the construction of urban agglomeration and coastal ecological corridor,and provides scientific reference for the identification of ecological security pattern and spatial optimization of forest urban agglomeration from the perspective of engineering restoration.