Spatial-temporal changes and prediction of carbon storage in Greater Khingan Mountains based on PLUS-InVEST model

Exploring the carbon storage capacity of terrestrial ecosystems under different land use scenarios is of great significance for improving regional carbon storage. Combining the InVEST and PLUS models, we analyzed the spatiotemporal characteristics of land use types and carbon storage in the Greater Khingan Mountains from 1992 to 2020, and forecasted the spatial and temporal changes in carbon storage under natural development, cropland protection, and ecological protection scenarios for 2030 and 2060. The results indicated that from 1992 to 2020, the dominant land use types in the study area were forest and cropland, accounting for more than 90% of the total area. The predominant land use changes were the expansion of forest and construction lands, accompanied by a decrease in the area of grasslands. Over the past three decades, the overall trend in carbon storage had shown an initial decrease followed by an increase, with a total increase of 1.89×10⁷ t. The spatial distribution of carbon storage was higher in the center and lower on the sides, with increases primarily driven by the expansion of forested areas. Under the cropland conservation scenario, the increase in carbon storage in 2030 and 2060 was expected to slow down, decreasing by 2.95×10⁶ and 1.00×10⁶ t, respectively, compared to the natural development scenario. Under the ecological conservation scenario, the carbon storage increased most significantly, with an increase of 9.40×10⁶ and 30.22×10⁶ t, respectively, compared to the natural development scenario. The cropland protection scenario could effectively ensure the quantity of arable land, yet the increase in regional carbon storage was relatively slow. In contrast, under the ecological conservation scenario, a substantial increase in the area of forests and other ecological lands significantly enhanced carbon storage. Future national land spatial planning for the Greater Khingan Mountains should comprehensively coordinate ecological priorities with cropland protection policies to enhance the region's carbon storage capacity and achieve green, high-quality development.