石羊河流域生态系统碳储量时空变化及多情景模拟

Spatial and temporal variability of ecosystem carbon storages and multi-scenario simulation in the Shiyang River basin

以石羊河流域为例,利用InVEST模型评估1990~2020年土地利用变化带来的碳储量效应,耦合PLUS模型模拟2035年在自然发展、生态保护、水资源约束和经济发展情景下土地利用变化及其对碳储量的影响.结果表明:石羊河流域土地利用主要以未利用地,草地和耕地为主,占流域总面积的93%.1990~2020年石羊河流域耕地,水域和建设用地面积呈增长趋势,其余用地面积呈减少趋势.2020~2035年多情景模拟下,只有生态情境中林地和草地面积增加显著.1990~2020年流域碳储量整体呈增长趋势,其中以草地,未利用地和耕地碳储量贡献为主,占碳总量的86%.2020~2035年4种情景下的碳储量均有所增加,但生态保护情景中碳储量增加最为显著,共增加3.75×10^(6)t.自然发展情景和经济发展情景下,林地和草地转为耕地的面积远大于转入,碳储量损失较多.水资源约束情景下,耕地主要转出为草地和建设用地,其他各地类之间转换所承载的碳储量基本平衡.生态保护情景下,林地,草地等生态用地转入面积大于转出使区域碳储量增加.研究结果以期为石羊河流域提升陆地生态系统碳储量和规划未来国土空间提供科学依据.

Take Shiyang River Basin as an example,the InVEST model was used to evaluate the effect of land use change on carbon storage from 1990 to 2020,and the coupled PLUS model was used to simulate land use change and its impact on carbon storage in 2035 under the scenarios of natural development,ecological protection,water resources constraint and economic development.The results showed that:The land use of Shiyang River Basin was mainly unused land,grassland and cultivated land,accounting for 93%of the total area of the basin.From 1990 to 2020,the area of cultivated land,water area and construction land in Shiyang River basin showed an increasing trend,while the other land area showed a decreasing trend.Under the multi-scenario simulation from 2020 to 2035,the area of forest land and grassland increased significantly only in the ecological scenario.From 1990 to 2020,carbon storage in the basin showed an increasing trend,and grassland,unused land and cultivated land contributed the most carbon storage,accounting for 86%of the total carbon.From 2020 to 2035,carbon storage increases under all four scenarios,but the ecological scenario has the most significant increase,with a total increase of 3.75×106t.Under natural and economic development scenarios,forest land and grassland were mostly converted into cultivated land,resulting in a greater loss of carbon storage.Under the water resource constraint scenario,cultivated land was mainly transferred to grassland and construction land,and the carbon storage carried by the conversion between other regions was basically balanced.Under the ecological protection scenario,the transfer area of forest land,grassland and other ecological land was larger than the transfer area,which increases the regional carbon storage.The results of this study were expected to provide scientific basis for improving carbon storage of terrestrial ecosystem and planning future territorial space in Shiyang River Basin.