Evaluating Carbon Sink Responses to Multi-Scenario Land Use Changes in the Dianchi Lake Basin: An Integrated PLUS-InVEST Model Approach

Land use and land cover changes are critical drivers of terrestrial carbon stock dynamics, as they alter native vegetation and land-based production activities. Scenario-based simulation of land use and carbon stock evolution offer valuable insights into the carbon sink potential of different development strategies and support low-carbon land planning. We focus on the Dianchi Basin, integrating a Markov-PLUS land use simulation with the InVEST carbon assessment model to examine carbon stock changes from 2000 to 2030 under three scenarios: natural development and cropland and ecological protections. Results indicate that from 2000 to 2020, the region experienced significant urbanization, with cropland decreasing and forest land expanding. Forests contributed the most to the total carbon storage, followed by cropland. The total carbon stock initially increased but experienced a marked decline from 2010 to 2020, aa trend expected to continue, largely attributable to the transformation of cropland and grassland into construction land, as well as the conversion of forest into cropland. By 2030, carbon stock trajectories would vary across scenarios. Both the natural development and cropland protection scenarios resulted in carbon loss, whereas the ecological protection scenario increased carbon storage and reversed the declining trend. Spatially, carbon stock distribution in the basin exhibits strong heterogeneity, with higher values in the periphery and lower values in the urban center. We reveal the spatio-temporal characteristics of carbon stock change and the carbon consequences of land use policies, providing scientific evidence to support land use restructuring, carbon sink enhancement, and regional carbon emission reduction under the dual-carbon goals of China.