耦合InVEST与FLUS模型的海南岛生态系统碳储量时空演变与预测

Spatial-temporal Evolution and Prediction of Ecosystem Carbon Storage on Hainan Island by Coupling InVEST and FLUS Models

[目的]通过研究海南岛城市化扩张下土地利用变化对碳储量的影响,揭示碳储量时空格局演变和预测未来发展趋势,为优化国土空间布局和生态敏感区的保护提供科学依据。[方法]基于1980—2020年土地利用数据,采用InVEST模型碳储量模块反演1980—2020年海南岛碳储量时空变化,并耦合FLUS模型和InVEST模型模拟自然发展情景、快速发展情景和生态保护情景3种发展情景下2030年海南岛的土地利用和碳储量变化情况。[结果](1)海南岛土地利用类型以林地、耕地为主。1980—2020年耕地、草地、林地和未利用地面积均有不同程度减少。建设用地和水域面积增加,尤以建设用地面积增长最快,增幅为83.4%。(2)海南岛碳储量总体呈“中间高,四周低”的特点,1980—2000年碳储量变化较小,降幅约0.03%。2000—2020年海南岛城镇化进程加快,碳储量损失也随之加剧,年均损失约372 t,累计损失碳储量7 439 t。(3)未来建设用地仍会继续扩张,受此影响3个情景下2030年海南岛碳储量均呈现降低的趋势。其中,快速发展情景下建设用地土地利用变化量最大,碳储量最易流失,自然发展情景次之,生态保护情景变化最小。[结论]在海南自由贸易港未来的土地利用规划中,应加强中部山区、自然保护地等重点生态区位的保护力度,优化土地利用格局,严格控制林地、耕地和湿地向建设用地转变,提高固碳增汇效能,实现区域可持续发展。

[Objective]The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas.[Methods]Based on land use data from 1980 to 2020,this research showed the spatial-temporal changes of carbon storage for Hannan Island.The data were used with the carbon storage module of the InVEST model.The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios:the natural development scenario,the rapid development scenario,and the ecological protection scenario.[Results]①The main types of land use on Hainan Island were forest land and cultivated land.From 1980 to 2020,the areas of cultivated land,grassland,forest land,and unused land decreased to varying degrees.The area of construction land and water increased over that time period,with the fastest growth rate being 83.4%for construction land.②Carbon storage for Hainan Island was generally characterized as“higher in the middle and lower in the surrounding areas”.Carbon storage changed slightly from 1980 to 2000,with a decrease of about 0.03%.From^(2)000 to 2020,the urbanization process on Hainan Island accelerated,and the loss of carbon storage also increased.The average annual loss was about 372 t,and the cumulative loss of carbon storage was 7439 t.③The prediction results showed that construction land will continue to expand in the future,and carbon storage on Hainan Island in 2030 will decrease under the three scenarios.Under the rapid development scenario,the land use change of construction land was the largest,and carbon storage was the most vulnerable to loss,followed by the natural development scenario.The ecological protection scenario had the smallest change.[Conclusion]Land Use Planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas,strengthening the nature reserves of Hainan Island,optimizing the land use pattern,and strictly controlling the transformation of forest land,cultivated land,and wetlands into construction land.The efficiency of carbon sequestration should be improved,and forest carbon sinks should be increased to achieve regional sustainable development.