道路景观胁迫下沿海滩涂地区生态网络构建与优化——以盐城市大丰区为例

Construction and optimization of ecological network under the stress of road landscape in coastal beach area:A case study of Dafeng District,Yancheng City

在沿海滩涂地区经济社会快速发展背景下,道路景观的无序扩张加剧了生境破碎化,使生物流通等过程受阻、生态系统服务功能受损。基于道路建设胁迫设置多阻力情景模拟生态网络,有助于揭示路网对关键生态过程的影响,优化区域生态安全格局。本研究以盐城市大丰区为例,基于GIS、Conefor Sensinode等平台,构建了基于景观类型赋值、依据道路两侧缓冲区修正赋值、依据路网高密度区修正赋值的3种阻力面情景,模拟生态网络并对其结构与格局进行定量评价。结果表明:中心城区、港口区等道路高密度区面积占全域比为8.21%,区内生境面临更高的道路景观胁迫风险;路网胁迫下,廊道绿地组分减少7.40%,曲度均值提升12.82%,生物迁移能耗显著增加;生态网络中沿海湿地对其他源地的作用力最强,可为生物迁移提供天然通道。量化道路密度等重要敏感性因子对阻力面赋值、生态网络组分结构的影响,有助于理解关键生态过程格局变化及驱动机制,为区域生态安全格局构建提供支撑。

Under the background of rapid economic and social development,the disorderly expansion of road landscape has aggravated habitat fragmentation,hindered biological circulation and impaired ecosystem services in coastal beach areas. Simulation of ecological network based on multiple resistance scenarios considering road construction stress is helpful to revealing the impacts of road network on key ecological processes and optimizing regional ecological security pattern. In this study,Dafeng District of Yancheng City was taken as a case study area and analyses were processed based on GIS,Conefor Sensinode,and other software platforms. Three kinds of resistance scenarios were established,which were based on landscape type assignment,modified according to the buffer zone on both sides of the road,and modified according to the high density zone of the road network,respectively. Lastly,ecological networks were simulated and quantitative evaluation on the structure and spatial pattern were conducted. The results showed that the ratio of high density areas of roads was about 8.21%,including central urban area and port area,in which the habitats faced with higher risk of road landscape stress. Under the stress of road network,the area of green land composition of corridors decreased by 7. 40%,and the mean curvature increased by 12. 82%,which implied that energy consumption of biological migration was significantly increased. The coastal wetland exerted the strongest effects on the other ecological sources in the ecological network,which could provide natural passages for biological migration. Furthermore,it is of great benefit to quantify the impacts of important sensitive factors,e.g. road density,on resistance surface assignment and component structure of ecological network,which can not only help understand the change and underlying mechanism of key ecological processes,but also provide effective support for the construction of regional ecological security pattern.