北部湾典型海岛生态系统服务价值空间异质性对比研究

A comparative study of spatial heterogeneity of ecosystem service value in typical islands in Beibu Gulf

基于北部湾海域典型海岛高分 1 号数据,借助于 CART 决策树方法,获取了广西北部湾两个典型海岛的景观格局数据,并采用生态系统服务价值计量模型、空间自相关模型及地统计学中的变异函数模型对其生态系统服务价值进行了空间异质性分析。结果表明:团和岛单位面积生态系统服务价值是七星岛的 1.08 倍,但其变异系数低于七星岛;七星岛由于其地质背景为泥沙岛,景观格局受到人类活动以及自然环境的强烈干扰,趋向于复杂化和破碎化;而团和岛由于所处的外部环境以及自身的地质特征,景观格局呈现出整体斑块化分布状态;团和岛的景观格局主要受到结构性因素的控制,而七星岛则以随机性因素控制为主,选用变程和 Moran’s 指数来表征其复杂化和破碎化,来决定其优先开发时序,可对前者进行适当开发,而对后者适当进行生态保护;对受到结构性因素影响的岛屿在进行开发时,时序的识别选用变程和 Moran’s 指数来表征,若变程和 Moran’s 指数越小,说明海岛整体的景观分布格局趋向于复杂化和破碎化,反之生态系统较好,可进行优先开发。同时本文构建了北部湾海岛生态系统异质性评估与自然资源管理框架,并提出了海岛管理的建议与对策。

Based on remote sensing data of two typical islands in Beibu Gulf, the landscape pattern data of islands were obtained using the CART decision tree method. Accordingly, the ecological system service value measurement model, the spatial autocorrelation model, and the variation function model were used for determining the spatial heterogeneity of the ecosystem service value. The per unit ecosystem service value in Thuanhe island was ap- proximately 1.08 times higher than that in Seven Star island;however, the coefficient of variation in Thuanhe island was lower than that in Seven Star island. Because of its geological background of mud and sand Island, the land- scape pattern of Seven Star island was strongly disturbed by human activities and natural environment, and its pat- tern tended to be complicated and fragmented, whereas the landscape pattern of Thuanhe island exhibited an entire patch due to its external environment and its own geological characteristics. The landscape pattern of Thuanhe is- land was primarily regulated by structural factors, whereas the Seven Star island was dominated by random factors. Therefore, Thuanhe island, which is regulated by structural factors, should be properly developed, and the Seven Star island, which is strongly influenced by nonstructural factors, should be appropriately protected. In the devel- opment of islands affected by structural factors, the identification of time series is characterized by range and Moran’s index. A smaller range and Moran’s index indicate more complexity and fragmentation. Otherwise, if the ecosystem were better, priority could be given to development. Finally, this paper constructs a framework for evaluating the island ecosystem heterogeneity and management of natural resources and suggests some counter- measures for island management.