闽三角城市群生态网络分析与构建

Ecological network analysis and construction:A case study of the urban agglomeration of the Min River Delta, China

快速城镇化进程导致区域生境斑块日益破碎化和孤岛化,科学构建生态网络是有效连接生境斑块的重要手段,对保障区域生物多样性和生态安全具有关键意义。以闽三角城市群为研究对象,依照"生态源地识别—阻力面设置—潜在廊道模拟"模式,根据生物栖息地适宜性评价识别生态源地,采用夜间灯光数据修正传统土地覆被赋值确定生态阻力面,基于最小累积阻力模型模拟潜在生态廊道。在此基础上,结合潜力模型进行廊道重要性评价,通过计算网络连通性指数和经济成本比确定廊道提取的合理阈值,提出生态与经济并重型生态网络构建方案。研究结果表明:(1)识别的生态源地共计45处,总面积约为3542 km2;模拟的潜在生态廊道共计990条,总长度约为5941 km。(2)源地及廊道的分布均呈现出显著的空间分异,研究区西北部山区丘陵地带的德化县、安溪县、南靖县等分布较为密集,而东南沿海建成区几乎没有分布。(3)0.73分位数所对应的网络连通性指数成本比达到最高值,此方案下提取的268条潜在廊道可有效连通45处生态源地。研究结果从生态保护与经济发展兼顾视角合理构建区域生态网络体系,可为闽三角城市群生态网络的建设优化提供科学依据。

Contemporary processes of urbanization present a major pressure on aggravating the fragmentation and isolation in ecological environment. Therefore, constructing ecological networks, as an effective way to connect fragmented habitats, becomes increasingly salient in maintaining biological diversity and enhancing ecological security. This study took the urban agglomeration of the Min River Delta, China, as the study context, and developed an optimized scheme for ecological network construction with the consideration of both network connectivity and construction cost. In this study, drawing on a series of indicators, including terrain, landscape, vegetation cover and human activities, a habitat suitability index was established to identify the habitats in the study area. The rectified night satellite images coupled with local land use were incorporated to build the ecological resistance surface. With the two essential elements habitats and ecological resistance surface as input, the ecological corridors were identified using the minimum cumulative resistance(MCR) model and then classified by a new accessibility potential model. Based on these classified ecological corridors, different schemes of ecological network were proposed by computing a set of connectivity indices. Given the network connectivity and construction costs, this study finally presented an optimized ecological network construction scheme. The results show that:(1)The identified habitats are 45, with a total area of 3542 km2;the 990 ecological corridors have a cumulative length of 5941 km;(2) Both habitats and ecological corridors are spatially concentrated in the northwestern hilly areas and seldom found in the northeastern coastal areas;(3) The maximum value of the ratio of network connectivity and construction costs is at the 73 th percentile. Under this scheme, 268 corridors connecting 45 habitats are identified. Our results may provide some scientific basis for constructing and optimizing the ecological network in the urban agglomeration of the Min River Delta.