Regional Carbon Stock Response to Land Use Structure Change and Multi-Scenario Prediction: A Case Study of Hunan Province, China

Abstract

Modifications in land use patterns exert profound influences on the configuration, arrangement, and functioning of terrestrial ecosystems, thereby inducing fluctuations in carbon sequestration. Consequently, precise ecological decision-making and an in-depth exploration of the interplay between land use alterations and carbon storage dynamics assume paramount importance in the pursuit of optimal regional land use configurations. In this investigation, we employed the InVEST model to analyze the spatiotemporal variations in land utilization and carbon storage in Hunan Province, based on comprehensive land use data spanning the period from 2000 to 2020. Additionally, the PLUS model was utilized to project the future spatial distribution of carbon storage in Hunan Province until 2040, encompassing diverse development scenarios. The findings of our study are as follows: (1) Land use changes instantaneously impact carbon storage within the study area. From 2000 to 2020, urban construction land witnessed an expansion of 3542 km2, which accounted for an increase from 1.13% to 2.78% of the total land area. Consequently, there was a decline in arable land, woodlands, and grasslands, resulting in a reduction of 3430.25 tons of carbon storage in Hunan Province. (2) The ecological protection scenario is projected to yield the most substantial increase in carbon storage, with an estimated magnitude of 7.02 × 10⁶ tons by the year 2040. According to the natural evolution scenario, the total amount of carbon storage is anticipated to remain similar to that of 2020, with a marginal increase of 2.81 × 10⁵ tons. Under the arable land protection scenario, carbon storage is predicted to decrease by 1.060 × 10⁷ tons. Conversely, the urban development scenario is expected to result in the most substantial reduction of 2.243 × 10⁷ tons of carbon storage. These findings underscore the efficacy of adopting ecological protection and natural development policies in curbing the decline in carbon storage. (3) The geographic distribution of carbon storage areas exhibits a strong correspondence with that of land use. Regions characterized by elevated carbon storage levels exhibit minimal urban construction land, an abundance of compact and contiguous ecological land, and a higher frequency of such land parcels. To enhance regional carbon storage levels and achieve sustainable development goals, future endeavors should prioritize the implementation of ecological protection and natural development policies.