整合绿地结构与功能性连接分析的城市生物多样性保护规划

Urban Biodiversity Conservation Planning Integrating Green Space Structural and Functional Connection Analysis

城市化进程和人口增长导致生物栖息地的破碎化和生物多样性的丧失,利用有效的模型和指标来评估景观连接度并用以构建绿地网络对于栖息地恢复和生物多样性保护具有重大意义。以北京市丰台区为例,首先,选用基于图论的连接度指数探讨适宜生物迁徙的绿地建设最优距离阈值,并根据景观连接度评价结果遴选源地斑块;其次,利用最小成本路径模型构建阻力面,采用Linkage Mapper工具确定物种迁徙的潜在连接路径;最后,根据电流密度量化源地斑块与廊道的相对重要程度,识别对物种迁徙至关重要的"夹点"地区,并将模型识别结果与遥感卫星地图以及鸟类丰度的经验观测结果进行对比校验。结果表明:研究区域西部绿地生态基底良好,为物种提供主要的栖息地;中部与东部地区绿地斑块破碎化严重,在夹点区域增加城市绿地作为物种迁徙的"垫脚石"十分必要。研究中引入聚焦于物种扩散的电路模型,弥补了城市绿地网络构建方法在生物多样性保护层面的欠缺,明确了北京市丰台区的生境质量现状与未来绿地网络发展脉络,为区域绿地格局优化以及生物多样性保护规划策略提供科学参考。

The urbanization process and population growth have led to the fragmentation of biological habitats and the loss of biodiversity.It is of great significance for habitat restoration and biodiversity protection to use effective models and indicators to evaluate landscape connectivity and build green space network.Taking Fengtai District of Beijing as an example,this research firstly applies the connectivity index based on the graph theory to explore the optimal distance threshold of green space construction suitable for biological migration,and selects the source patches according to the evaluation results.Secondly,it uses the least cost path model to construct the resistance surface,and the Linkage Mapper tool to determine the potential connection path of species migration.Finally,it identifies the“pinch point”area which is vital for species migration by quantifying the relative importance of the source patches and corridors with the circuit density,and compares the results with the remote sensing satellite map and empirical observation of bird abundance.The results show that the ecological base of the green space in the west region is good,which provides the main habitat environment for the species.The green patches in the central and eastern regions are seriously fragmented.Therefore,it is necessary to increase the urban green space in the pinch areas as stepping stones for species migration.In this research,the circuit model focusing on species diffusion is introduced to make up for the limitations of other green space network construction methods,and clarify the current situation of habitat quality and the future development of green space network in Fengtai District of Beijing,which can provide scientific reference for the optimization of regional green space patterns and the formulation of biodiversity conservation planning strategies.