[Spatiotemporal variation and future scenario simulation of ecosystem carbon storage in the Hulun Lake Basin, Inner Mongolia, China]

Abstract

Carbon storage in terrestrial ecosystems plays a crucial role in climate change and the global carbon cycle. To investigate the spatiotemporal variations of carbon storage in the Hulun Lake Basin, we combined the InVEST and PLUS models to systematically analyze the impacts of land use changes from 1990 to 2020 on carbon storage, and simulate land use patterns and spatial distribution of carbon storage under different scenarios for 2030. The results indicated that the Hulun Lake Basin experienced significant changes in land use distribution during 1990-2020. The area of cultivated land, forest, bare land, and built-up land increased, while the area of grassland, water, and wetlands decreased. Total carbon storage in the basin increased by 1.48×10⁷ t, with a growth rate of 1.0%. Carbon storage in forest and cultivated land increased by 7.18×10⁷ and 6.7×10⁶ t, while that in grassland, water, and wetlands decreased by 6.01×10⁷, 1.8×10⁶, and 1.7×10⁶ t, respectively. Carbon storage in the basin exhibited significant spatial heterogeneity, with higher carbon storage areas mainly distributed in the eastern hilly areas of the basin and lower carbon storage areas mainly located in the northeastern part of the basin and around Hulun Lake. The spatial differentiation showed a strong coupling relationship with land use patterns. Under the four scenarios for 2030, including natural development, urban development, cropland protection, and ecological conservation,carbon storage in the Hulun Lake Basin showed an increasing trend, with the ecological conservation scena-rio demonstrating the most significant growth of 6.19×10⁶ t and a growth rate of 0.4%. Our findings would provide important references for optimizing land use pattern and enhancing carbon storage capacity in the Hulun Lake Basin.

Keywords: InVEST model; PLUS model; carbon storage; multi-scenario simulation; the Hulun Lake Basin.