基于粒度反推法的景观生态安全格局优化——以海口市秀英区为例

景观生态安全格局优化是改善生态环境、促进人与自然和谐发展的有效途径。为给海口市秀英区生态环境建设提供科学依据和景观生态安全格局优化方法改进提供参考,提出了粒度反推法和生态阻力面综合构建法,结合GIS技术和最小耗费距离模型探讨了海口市秀英区景观生态安全格局优化途径。结果表明:(1)400m粒度生态景观组分是秀英区生态源地选取的合适参照,秀英区有生态源地18块、生态廊道17条、生态节点11个,新增生态源地建设的参考规模为38.5hm2,生态源地的生态服务极限距离为800m,需将现有的11块非生态景观类型斑块转换为生态景观类型,总面积20.26 hm2。(2)粒度反推法能为生态源地选取提供客观参考,在生态源地选择方面比传统方法具有更强的理论基础和客观性,解决了客观选取生态源地的问题。(3)综合生态阻力面能对生态阻力的实际情况进行较好地模拟。显、隐性生态阻力面之间存在显著差异,能反映生态系统中潜在的生态薄弱点,这些生态薄弱点往往是容易被忽略而又需要重点建设的区域。

Landscape ecological security pattern optimization based on the granularity inverse method: a case study in Xiuying District, Haikou

The Landscape Ecological Security Pattern Optimization Approach (LESPOA) is an effective way of promoting healthier ecosystems and harmonious relationships between people and their surrounding environment. Currently, there are shortcomings to this approach because it lacks objectivity in ecological site selection, and when simulating ecological resistances, it doesn''t consider the interactions between these resistances. In order to address these issues, this paper uses the granularity inverse method and the comprehensive construction method of ecological surface resistance, which combines the technology of GIS with a least-cost distance model, to apply the LESPOA in Xiuying district. We aimed to provide a scientific basis for ecological environment construction and a method for improving the LESPOA. The results were: (1) When the granularity of ecological landscape component is 400 m, the ecological landscape component is an appropriate method for selecting ecological sources. According to the above appropriate method, there were 18 ecological sources (8 primary and 10 secondary), 17 ecological corridors, and 11 ecological nodes in Xiuying district. The reference scale of new ecological sources was 38.5 hm². The maximum ecological service distance for whole ecological source structure was about 800 m. When the distance between different ecological patches is approximately 200 m, we should enhance the ecological connections between them. Currently, there are 11 non-ecological landscape patches (with a total area of 20.26 hm²) in Xiuying district that need to be converted to ecological landscape patch;(2) The granularity inverse method has a stronger theoretical basis and greater objectivity than traditional methods of ecological source selection, and it also can reflects the connective characteristics of landscape pattern. Therefore, the results from this method can supply more accurate references for ecological construction than traditional methods. (3) The comprehensive ecological resistance surface considers the interaction between resistances and thus can better simulate the physical characteristics of ecological resistances than the traditional ecological resistance surface that just considers land use type. There are significant differences between dominant ecological resistance and recessive ecological resistance, which can reflect potential ecological weak points. Most of the ecological weak points in Xiuying district are woodlands that are surrounded by farmland, unused land, and construction land. Although these ecological weak points can easily be neglected, it is important to focus on enhancing the connections between the weak points and ecological sources in order to restore natural ecologic processes.