Impacts of land use and cover change on carbon storage: Multi-scenario projections in the arid region of Northwest China

Abstract

Carbon storage serves as a key indicator of ecosystem services and plays a vital role in maintaining the global carbon balance. Land use and cover change (LUCC) is one of the primary drivers influencing carbon storage variations in terrestrial ecosystems. Therefore, evaluating the impacts of LUCC on carbon storage is crucial for achieving strategic goals such as the China’s dual carbon goals (including carbon peaking and carbon neutrality). This study focuses on the Aral Irrigation Area in Xinjiang Uygur Autonomous Region, China, to assess the impacts of LUCC on regional carbon storage and their spatiotemporal dynamics. A comprehensive LUCC database from 2000 to 2020 was developed using Landsat satellite imagery and the random forest classification algorithm. The integrated valuation of ecosystem services and trade-offs (InVEST) model was applied to quantify carbon storage and analyze its response to LUCC. Additionally, future LUCC patterns for 2030 were projected under multiple development scenarios using the patch-generating land use simulation (PLUS) model. These future LUCC scenarios were integrated with the InVEST model to simulate carbon storage trends under different land management pathways. Between 2000 and 2020, the dominant land use types in the study area were cropland (area proportion of 35.52%), unused land (34.80%), and orchard land (12.19%). The conversion of unused land and orchard land significantly expanded the area of cropland, which increased by 115,742.55 hm². During this period, total carbon storage and carbon density increased by 7.87×10⁶ Mg C and 20.19 Mg C/hm², respectively. The primary driver of this increase was the conversion of unused land into cropland, accounting for 49.28% of the total carbon storage gain. Carbon storage was notably lower along the northeastern and southeastern edges. By 2030, the projected carbon storage is expected to increase by 0.99×10⁶, 1.55×10⁶, and 1.71×10⁶ Mg C under the natural development, cropland protection, and ecological conservation scenarios, respectively. In contrast, under the urban development scenario, carbon storage is projected to decline by 0.40×10⁶ Mg C. In line with China’s dual carbon goals, the ecological conservation scenario emerges as the most effective strategy for enhancing carbon storage. Accordingly, strict enforcement of the cropland red line is recommended. This study provides a valuable scientific foundation for regional ecosystem restoration and sustainable development in arid regions.