基于MCR和重力模型的县域生态安全格局构建——以福建省永春县为例

County Scale Ecological Security Pattern Construction Based on MCR Model-A Case Study of Yongchun County,Fujian Province

[目的]构建具有区域特色的生态安全格局,为生态环境的保护及县域尺度下的生态安全格局构建和分区管理提供科学参考。[方法]以福建省永春县为研究对象,参考《生态保护红线划定指南》,选取水土保持、水源涵养、生物多样性保护及对永春县生态具有重要作用的林业保护共4项指标进行定量评估,以识别源地;利用最小累计阻力模型(minimal cumulative resistance,MCR)和重力模型的方法,构建生态廊道并对廊道的重要性进行分级评价,提取生态节点,构建永春县生态安全格局。[结果]识别出的永春县生态源地共11块,总面积为64.8 km^(2),占区域总面积的4.45%;构建了55条生态廊道和27个生态节点,其中重要廊道25条,次要廊道30条,集中在中部和东部地区呈网状分布。[结论]依据生态源地识别和廊道划分结果,构建了永春县以源地为核心,廊道为网络,生态节点为重点的生态安全格局框架,生态源地间相互作用强度差异明显,中部地区源地分布密度和生态廊道稳定性大于西部地区,应作为重点保护区域。

[Objective]An ecological security pattern with regional characteristics was constructed in order to provide a scientific reference for the protection of the ecological environment and the construction and zoning management of ecological security patterns at the county level.[Methods]Referring to the Guide for Delimitation of Ecological Protection Red Lines,we selected four indicators for quantitative evaluation of ecology at Yongchun County in Fujian Province:soil and water conservation,water conservation,biodiversity protection,and forestry protection.The minimum cumulative resistance(MCR)model and the gravity model were used to build the wildlife corridor,evaluate the importance of the corridor by grades,extract ecological nodes,and construct the ecological security pattern of Yongchun County.[Results]A total of 11 ecological source areas were identified in Yongchun County,with a total area of 64.8 km^(2),accounting for 4.45%of the total area.Fifty-five ecological corridors and 27 ecological nodes were constructed,including 25 important corridors and 30 secondary corridors that were concentrated in the central and eastern regions with a reticular distribution.[Conclusion]According to the results of ecological source identification and corridor division,an ecological security pattern framework for Yongchun County was constructed,with source as the core,corridor as the network,and ecological nodes as the focus.The interaction intensities between ecological source areas were obviously different.The distribution densities of source areas and the stability of the wildlife corridor in the central region were greater than in the western region,and should be regarded as key protection areas.