基于InVEST模型的洞庭湖生态经济区生态系统服务功能研究

Land Ecosystem Service Functions for Dongting Lake Ecological Economic Zone Based on InVEST Model

[目的]探讨洞庭湖的生态服务功能物质量空间分布情况,提升研究区乃至长江流域生态系统服务功能,为土壤保持、土地利用和生态保护提供参考。[方法]基于InVEST模型,以洞庭湖生态经济区为研究区域,评估2005,2018年水源涵养、土壤保持、碳储存和生境质量4项生态系统服务物质量及4项生态系统服务功能间的权衡关系。[结果](1)土地利用转化以林地和耕地、水域和耕地间相互转化以及林地、耕地转化为建设用地为主。(2)水源涵养和土壤保持功能显著提升,碳储存和生境质量功能略微下降。(3)水源涵养、碳储存、生境质量功能物质量低值区分布在研究区中部湖区附近,而高值区分布在东部地区;土壤保持功能物质量的高值区主要分布在东部、西南部和西北部地区。[结论]受经济发展客观需要和退田还湖、退耕还林等相关生态保护政策影响,研究期内洞庭湖区土地利用情况、生态系统服务功能物质量均发生较大变化,且研究区内水源涵养和生境质量之间为权衡关系,水源涵养和土壤保持之间为兼容关系,其他各项生态系统服务间均为协同关系。InVEST模型对生态系统服务功能的评估更全面。

[Objective]The spatial distribution of ecosystem services for Dongting Lake was studied to improve the ecosystem services in the study area and in the Yangtze River Basin,and provide a reference for soil conservation,land use,and ecological protection.[Methods]The tradeoff relationship between the quality of four ecosystem services and the four ecosystem service functions of water conservation,soil conservation,carbon storage,and habitat quality in 2005 and 2018 was evaluated for the Dongting Lake Ecological Economic Zone using the InVEST model.[Results]①Land use conversion was mainly based on conversion between forest land and cultivated land,water area and cultivated land,and conversion of forest land and cultivated land into construction land.②The water source conservation and soil conservation functions were significantly improved,and the carbon storage and habitat quality functions were slightly reduced.③The low-value areas of water conservation,carbon storage,habitat quality,and functional substance quality were located near the central lake area of the study area,while the high-value areas of soil conservation functional material quality were mainly located in the east,southwest,and northwest.[Conclusion]Land use and the quality of ecosystem services in the Dongting Lake ecological economic zone changed greatly during the study period as the area was affected by the objective needs of economic development and relevant ecological protection policies(such as returning farmland to lakes and returning farmland to forests).There is a tradeoff relationship between water conservation and habitat quality in the study area,a compatible relationship between water conservation and soil conservation,and a synergistic relationship among other ecosystem services.The InVEST model provides a more comprehensive assessment of ecosystem service functions.