多情景模拟下重庆市土地利用变化对生态系统健康的影响

Impacts of land use change on ecosystem health in Chongqing under multiscenario simulation

模拟多情景下区域土地利用变化引起生态系统健康状况改变,对优化用地格局和保障区域生态安全具有重要意义。基于重庆市2000—2020年土地利用和生态系统健康动态演变特征,运用生态系统健康模型和斑块生成土地利用模拟(PLUS)模型模拟自然发展(ND)、生态保护(EP)和城镇发展(UD)三种情景下土地利用变化对生态系统健康的影响程度。结果表明:(1)2000—2020年建设用地扩张迅速,耕地面积减少最多,主要向林地和建设用地转移;生态系统健康状况整体呈现向好趋势,但区域差异显著。(2)2030年土地利用类型仍以耕地、林地为主,ND、EP和UD情景的建设用地规模较2020年分别增加63.59%、44.54%和100.13%,中心城区成为建设用地扩张集聚地。(3)2030年ND和UD情景的生态系统健康值较2020年均减小,建设用地增加和林地减少成为其健康退化的重要原因;而EP情景的健康值呈上升趋势,与反映生态系统健康对土地利用变化响应弹性结果相反,可见EP情景下的土地利用优化是实现区域生态系统健康可持续发展的有效途径。研究结果可为研究区生态系统保护管理与土地利用政策优化提供参考依据。

Land use change profoundly influences the regional ecosystem.Due to the increase of the human activity intensity and social demand,the negative impacts on the ecosystem health will last for a long time.Simulating the change of ecosystem health caused by land use change under multi⁃scenario is significant for regional land use patterns optimization and ecological security protection.However,previous studies have mainly focused on the influence of land use change on ecosystem structure or services,while few have explored and predicted its impacts on ecosystem health.In this study,taking Chongqing as the study area,we first analyzed the dynamic evolution characteristics of land use and ecosystem health in Chongqing from 2000 to 2020.Based on this,using the ecosystem health assessment model and the patch-generating land use simulation(PLUS)model,three scenarios(i.e.,natural development(ND)scenario,ecological protection(EP)scenario,and urban development(UD)scenario)were performed to simulate the impacts of land use change on ecosystem health in 2030.The results show that:(1)From 2000 to 2020,the area of construction land increased,while the cultivated land area decreased,with the reduced land primarily transferring to forestland and construction land.The overall ecosystem health showed a positive trend but the regionally spatial distribution was significantly different.The level of ecosystem health in the northeast and southeast regions was higher than in the southwest region.(2)The land use types were still mainly cultivated land and forestland by 2030,and the area of construction land for ND scenario,EP scenario,and UD scenario increased significantly,with the increase of 63.59%,44.54%,and 100.13%,respectively.The central urban area in the southwest would become the area of construction land expansion.(3)Compared with those in 2020,the ecosystem health values of ND scenario and UD scenario showed a declining trend.The expansion of construction land area and the reduction of forestland area were important factors contributing to the degradation of ecosystem health in those scenarios.However,EP scenario showed an increasing trend,which was contrary to the results that reflected the elasticity of the response of ecosystem health to land use change.Therefore,land use optimization under EP scenario was effective for the sustainable development of regional ecosystem health.In summary,the estimation of the impacts of land use change on ecosystem health with the coupling multi⁃model could provide valuable references and decision⁃making support for ecosystem protection management and land use policy optimization in the study area.