[Multi-scenario Land Use Optimization and Carbon Storage Assessment in Northwest China]

Land use/cover change (LUCC) is the main factor leading to the change in carbon stock of terrestrial ecosystems. Studying the process of land use and carbon storage change under different scenarios in the future will help to formulate scientific land use policies and increase regional terrestrial ecosystem carbon storage. The GMMOP-PLUS-InVEST model was constructed to analyze the change characteristics of land use and carbon storage in northwest China from 2000 to 2020 through multi-source data and to predict the land use and carbon storage in northwest China in 2030 under the scenarios of natural development (ND), economic development (ED), ecological protection (EP), and comprehensive development (CD). The results showed that:①from 2000 to 2020, the area of grassland decreased by 1680.99×10⁴ hm², and the area of cultivated land, forest land, water area, wetland, construction land, and unused land increased by 201.19×10⁴, 208.47×10⁴, 91.54×10⁴, 51.30×10⁴, 157.40×10⁴, and 971.09×10⁴ hm², respectively. ②From 2000 to 2020, soil and underground carbon storage decreased, dead organic matter and aboveground carbon storage increased, and total carbon storage decreased by 677.97×10⁶ t. Grassland degradation was the main reason for the decrease in carbon storage. ③Compared to that in 2020, the total carbon storage in the ND scenario was reduced by 63.12×10⁶ t, and the total carbon storage in the ED, EP, and CD scenarios increased by 759.19×10⁶, 804.57×10⁶, and 817.89×10⁶ t, respectively; the CD scenario was the optimal development model. These results can provide a reference for regional land use planning and the increase of terrestrial ecosystem carbon storage.