Effects of land use change on the temporal and spatial pattern of carbon storage in Guanzhong Plain urban agglomeration

The change in carbon storage in an ecosystem is closely related to the pattern of land use and studying changes in carbon storage is of great importance for achieving the dual carbon goal. The Guanzhong Plain urban agglomeration is the western region’s second-largest urban agglomeration, and the implementation of the national strategy affects the type of land use, which in turn affects the spatial and temporal distribution of carbon storage. By coupling the InVEST and PLUS models, this study analyzed the temporal and spatial evolution characteristics of land use types and carbon storage in the Guanzhong Plain urban agglomeration from 2000 to 2020 and then predicted the changes in land use and carbon storage in the urban agglomeration of the Guanzhong Plain in 2030 under three scenarios: natural evolution, ecological protection, and economic development. The results showed the following: 1) From 2000 to 2020, the main land use types in the Guanzhong Plain urban agglomeration were arable land and forest land, with the conversion of grassland to cultivated land, and forest land and cultivated land to construction land being the most common types of land use conversion in the study area. 2) The predicted 2030 changes show that the cultivated land area of the Guanzhong Plain urban agglomeration tends to decrease under all three scenarios. Under the scenarios of natural evolution and economic development, the areas of forestland and grassland show a decreasing trend and a significant expansion of construction land. Under the ecological protection scenario, forestland and grassland areas show an upward trend, while construction land decreases slightly. 3) From 2000 to 2020, the major reason for the reduction in carbon storage was the shrinkage of forest land and grassland, which decreased by 7.02×10⁶ t. 4) In the 2030 changes, under the scenarios of natural evolution and economic development, both construction land and cultivated land in the Guanzhong Plain will expand significantly and the carbon storage will be significantly reduced; under the ecological protection scenario, the expansion area of construction land is relatively small, the carbon storage in the central and northeastern regions does not decrease significantly, and the overall carbon storage increases in a scattered manner. The results provide a scientific basis for future urban planning and land space management in the Guanzhong Plain urban agglomeration. In the future, the Guanzhong Plain urban agglomeration can be further developed based on ecological protection scenarios and construction land expansion can be limited while protecting the ecology.