Spatial-temporal evolution analysis of multi-scenario land use and carbon storage based on PLUS-InVEST model: A case study in Dalian, China

Carbon storage in terrestrial ecosystems varies with land use changes, and exploring the impact of land use changes on carbon storage in regional terrestrial ecosystems is important for maintaining regional carbon balance. Data on Dalian City's land use types from 2000 to 2020 are used in this research, to evaluate the spatiotemporal evolution of carbon storage in Dalian. Furthermore, with the scenarios of urban development, natural development, cultivated land protection, and ecological protection in 2030, this study combines the PLUS and InVEST models to emulate the dynamic adjustment at land-use types and the spatio-temporal evolution regarding carbon storage in Dalian City. The investigation shows that: 1) The carbon storage of terrestrial ecosystem in Dalian has been altered as a consequence of changes in land use, and now it shows a general decline during 2000-2020, with reductions amounting to 5.39 x 106 t. 2) From 2000 through 2020, Dalian's land resources that are utilized for farming, forestry, and grassland decreased to different degrees. The total construction land area increased by 796.47 km2, or 6.38 %, whereas there has been no substantial improvement in water or unused land. 3) The carbon storage reduction in 2030 in comparison to 2020 for the natural development, cultivated land protection, and urban development scenarios, among which the urban development scenario was the largest, was 1.36 x 106t. It suggests that the rapid rate of urbanization and expansion of construction land is an important cause of the decline in carbon storage. 4) The cultivated land protection scenario (CPS) yields the smallest reduction of 6.50 x 105t. The structure of Dalian's land use type is optimum under the ecological protection scenario (EPS), as seen by the 3.90 x 105t increase in carbon storage under this scenario. It speeds up the rate of recovery of carbon storage and improves the function of carbon sinks in urban terrestrial ecosystems. Hoping to provide the reference to decision makers for ecosystem carbon storage optimization from the view of land use, which is vital for making future land use policies and realizing the "dual carbon" strategic goal.