近40年海南岛国土空间格局演化的生态效应及其影响因素

Ecological effects and its influencing factors of Hainan Island′s territorial spatial pattern evolution in the past 40 years

科学认知国土空间格局演化与生态服务的关联作用及主导影响因素,可为区域国土空间开发和生态环境保护提供决策支持。采用空间转移矩阵、InVEST模型分析1980—2020年海南岛国土空间格局及生态系统服务的时空演化特征,并在此基础上引入综合生态服务指数(CESI)和国土空间转型生态贡献率评估国土空间格局演化的生态效应,最后运用随机森林模型探究生态系统服务演化的主导因素及作用机制。结果表明:(1)近40年海南岛城镇空间持续扩张,农业空间不断缩减,生态空间先增后减,全域国土空间交叉转化总规模达到2717.11km^(2),其中以生态空间与农业空间的动态转换最为显著,生态空间和农业空间向城镇空间转换次之,城镇空间向生态空间和农业空间的转换最弱。(2)生态系统服务功能中产水量分布呈现“东北部高、西南低”的分布特征,土壤保持、碳储量、生境质量及综合生态服务指数分布则表现为“中部高、四周低”,40年间各类生态系统服务功能均呈现不同的程度的下降趋势,这是海南岛生态系统服务功能恶化趋势大于改善趋势的结果,其中生态空间向农业空间和城镇空间的转换是区域生态服务功能恶化的重要原因。(3)海南岛生态服务功能受到自然地理、交通区位、社会经济和政策的综合作用,交通区位、社会经济以及自然地理类因素影响作用显著,政策类因素影响相对较弱,且各影响因素与生态系统服务功能间呈现非线性相关关系。

Understanding the intricate relationship between the evolution of territorial spatial patterns and ecosystem services,along with identifying the dominant influencing factors,can provide essential decision-making support for regional territorial development and ecological environmental protection.This study utilized spatial transition matrices and the InVEST model to analyze the spatiotemporal evolution characteristics of Hainan Island′s territorial spatial patterns and ecosystem services from 1980 to 2020.Based on this,a comprehensive ecosystem service index(CESI)and a territorial space transformation ecological contribution rate were introduced to assess the ecological effects of territorial spatial pattern evolution.The Random Forest model was then applied to explore the leading factors and mechanisms influencing ecosystem service evolution.The results indicate that:①Over the past four decades,Hainan Island has seen continuous urban space expansion,a reduction in agricultural space,and an initial increase followed by a decrease in ecological space.The total scale of cross-transformation in territorial space reached 2717.11 km^(2),with the dynamic transformation between ecological and agricultural spaces being the most significant.The conversion of ecological and agricultural spaces into urban space was next in significance,while the transformation of urban space into ecological and agricultural spaces was the weakest.②The distribution of water yield among ecosystem service functions showed a high in the northeast,low in the southwest pattern,while soil conservation,carbon storage,habitat quality,and the comprehensive ecosystem service index were high in the center,low around the edges.Over 40 years,all types of ecosystem service functions have shown varying degrees of decline,a result of the deterioration trend in Hainan Island′s ecosystem service functions outweighing the improvement trend.The conversion of ecological space to agricultural and urban spaces was a significant reason for the regional ecological service function deterioration.③The functionality of Hainan Island′s ecosystem services was influenced by a combination of natural geography,transportation location,socio-economic factors,and policies.Transportation location,socio-economic,and natural geographic factors had significant impact,while policy factors were relatively weak.Furthermore,the relationship between these influencing factors and ecosystem service functions was nonlinear.