基于MSPA与最小路径方法的巴中西部新城生态网络构建

目前快速城市化导致了生境斑块的日益破碎化,景观之间的连通性不断降低。构建生态网络可以连接破碎的生境斑块,增加绿地景观的连通性,对生物多样性保护具有重要意义。以高度景观破碎化的四川省巴中西部新城为研究区,采用形态学空间格局分析(MSPA)方法,提取出对研究区生态网络构建具有重要生态意义的核心区和桥接区两类景观要素,并选用整体连通性(IIC)、可能连通性(PC)和斑块重要性(d I)等景观指数,分别对核心区和桥接区进行景观连接度评价,遴选出对维持景观连通性贡献最大的10个核心区生境斑块作为生态网络的源地,并根据斑块对维持景观连通的重要性程度将其他核心区和桥接区进行类型划分,以此作为景观阻力的赋值依据,融入消费面模型中,最后采用最小路径方法构建了研究区潜在的生态网络,并基于重力模型对重要生态廊道进行了识别与提取,在此基础上有针对性地提出了生态网络优化的对策。研究结果表明,MSPA方法能够科学的辨识出研究区内对生态保护具有重要意义的结构性要素,例如作为物种栖息地的核心区和物种迁移通道的桥接区,这些要素是生态网络的重要组成部分;景观连通性的计算,明确了研究区景观要素的保护重点,为最小路径方法中的景观阻力赋值提供了重要的参考信息;基于MSPA与最小路径方法的生态网络分析框架综合了现有景观结构性要素识别、连通性分析以及物种潜在迁移路径分析等方法,将景观中潜在的生态源地和结构性廊道的连通性作为构建生态网络的重要基础和主要依据,从而使得生态网络的构建更科学。研究结果可为高度破碎化地区生态网络的构建提供重要的参考与依据,对其他地区生态网络的构建也具有一定的借鉴意义。

Developing ecological networks based on mspa and the least-cost path method: a case study in bazhong western new district

Rapid urbanization and economic development in China has resulted in urban sprawl and has also led to a reduction of natural resources and habitat fragmentation in urban areas. Habitat fragmentation and the resultant decrease in habitat connectivity has become a serious challenge for biodiversity conservation. Green spaces are important habitat resources in the city. The development of green space ecological networks can be used to increase the connectivity between fragmented habitat patches, which promotes urban biological diversity conservation. Taking Bazhong western new district, a rapidly urbanizing area in Sichuan, China, as a case study, a novel method is proposed using Guidos, GIS and the gravity model to develop green space ecological networks.First, the morphological spatial pattern analysis (MSPA) model in the software Guidos was used to identify the main types and structure of green spaces in the landscape. The "cores" and "bridges" were extracted, which will make the foundation of the green space network. Second, using the software Conefor, the integral index of connectivity (IIC), probability of connectivity (PC) and the percentage of importance (dI) of each individual element were used to evaluate the relative importance of these cores and bridges to landscape connectivity. Accordingly, the top ten core patches acting as ecological sources were identified. The remaining cores and bridges were ranked based on their importance in maintaining ecological network connectivity. Finally, using GIS, potential ecological networks were developed using the least-cost path method, and the important corridors were identified using the Gravity model. A plan to optimize the ecological network in the study area was put forward. This research shows that the structural elements, the cores and bridges of ecological networks can be identified via the MSPA method and that landscape connectivity measurements (IIC, PC and dI) provide good quantitative measures of the relative importance of landscape patches, especially when considering landscape patch spatial distributions. The evaluation of landscape patches can help to identify and extract important protected landscape elements. Least-cost path analysis also provides important reference information for evaluating landscape patch habitat quality, which most previous researches have evaluated by subjective assessments. The research results show that the combination of MSPA with measures of landscape connectivity and least-cost path analysis are a novel and useful method for developing green space ecological networks in urban and other fragmented areas. The results will help to guide the development and management of green spaces for biodiversity conservation.