Spatiotemporal variation and dynamic simulation of carbon stock based on PLUS and InVEST models in the Li River...

The watershed is the optimal natural division for ecosystems, playing a crucial role in carbon reduction and sequestration. Exploring the carbon sequestration potential of terrestrial ecosystems under different land use scenarios and enhancing regional carbon storage capacity is of significant importance. In this study, the LUCC in the Lijiang River basin under the scenarios of natural evolution (NE), natural conservation (NC), urban developmentand (UD) and farmland protection (FP) in 2040 was simulated by using grid data, driver grid data and carbon density data, based on the PLUS model and the InVEST model. Then, the effects of land use change on carbon stock in the Lijiang River Basin from 2000 to 2040 were evaluated. The results show that, (1)from 2000 to 2020, the area of arable land significantly increased in the Li River Basin, while forest and grassland areas decreased significantly. The distribution pattern of land use in the Li River Basin is mainly influenced by factors such as economy, population density, topography, and roads. Population growth and economic development require more arable land, forest land, and construction land. (2)Due to land use change, the carbon stock in the Li River Basin decreased by 3.69 × 10⁶ t over the 20-year period, particularly in the northern and southern regions of the basin. (3)Meanwhile, there was a significant change in the land use pattern, with forest carbon stock accounting for a reduced proportion (90.76%) of the total ecosystem carbon stock in 2020. (4)According to the projected natural evolution scenario, the carbon stock in 2040 will decrease by 3.13 × 10⁶ t compared to 2020 in the Li River Basin. Under the scenario of arable land protection, the carbon stock will decrease significantly. Under the ecological protection scenario, the carbon stock of the terrestrial ecosystem will increase by 2.75 × 10⁵ t. Under the urban development scenario, the carbon stock caused by land use change will be uncertain; however, construction land increase will definitely cause the decrease of carbon stock.This study examines the impact of land use change scenarios on carbon storage in the Li River Basin, highlighting the potential carbon gains under the ecological conservation scenario, providing valuable insights for regional land use planning and carbon reduction strategies.