Objective The Demonstration Zone of Green and Integrated Ecological Development of the Yangtze River Delta (hereinafter referred to as the “Demonstration Zone”) holds strategic significance in achieving China’s carbon neutrality and carbon peaking goals. This research focuses on the critical need to evaluate the spatiotemporal dynamics of carbon storage under rapid land use changes, with a focus on improving the accuracy of carbon density estimation, and to construct a three-tiered zoning framework based on the carbon density gradient. The objectives are to overcome the limitations of static carbon density assumptions inherent in traditional methodologies and to bridge the gap between theoretical carbon storage models and practical governance strategies, thereby identifying and providing a framework for regional carbon management.

Methods To achieve these objectives, the research develops a novel carbon density correction method that integrates climatic factors and land use characteristics, overcoming the limitations of fixed carbon density values in traditional approaches. The InVEST model, a widely used tool for ecosystem service assessment, is employed to quantify carbon storage changes from 2000 to 2020. Land use data from three time points (2000, 2010, and 2020) are analyzed to identify the spatiotemporal patterns of carbon storage. A land use transition matrix is constructed to reveal the primary drivers of carbon storage changes. Additionally, spatial autocorrelation analysis is conducted to identify clustering patterns of carbon storage. Based on carbon density variations, the research establishes a three-tier carbon functional zoning system that involves carbon sink enhancement zones, carbon balance zones, and carbon emission control zones. This zoning framework provides a foundation for targeted carbon management strategies.

Results 1) From 2000 to 2020, carbon storage in the Demonstration Zone exhibited a distinct V-shaped trajectory, declining initially and then recovering. Specifically, it is estimated that the total carbon storage was respectively 3.17×10⁷ t in 2000, 2.58×10⁷ t in 2010 and 3.26×10⁷ t in 2020. The decline from 2000 to 2010 was primarily driven by the expansion of construction land, which encroached on significant areas of farmland and forestland. However, from 2010 to 2020, large-scale forest restoration efforts led to a net increase in carbon storage. 2) Although the expansion of construction land encroached on substantial forestland and farmland from 2000 to 2010, the significant restoration of forestland from 2010 to 2020 resulted in a net positive carbon storage change. Spatial analysis indicates that carbon storage was concentrated in the northwestern and eastern parts of the Demonstration Zone, with lower values observed near inland water bodies and administrative boundaries. This spatial heterogeneity highlights the influence of land use types and geographic features on carbon storage distribution. 3) The delineation of carbon functional zones reveals a notable increase in carbon balance zones and a reduction in carbon emission control zones. This shift reflects a transition toward more concentrated carbon storage and enhanced carbon sink functions. The growth of carbon sink enhancement zones is largely attributed to ecological restoration policies, such as the conversion of farmland to lakes and forests, underscoring the critical role of policy interventions in enhancing carbon sequestration capacity.

Conclusion Based on these findings, the research proposes a spatially differentiated low-carbon governance framework for the Demonstration Zone, and emphasize three pillars. 1) Zonal Regulation: Implement strict protection measures in carbon sink enhancement zones, optimize land use efficiency in balance zones, and enforce emission reduction targets in control zones. 2) Ecological restoration priorities: Scale up reforestation, wetland conservation, and “sponge city” initiatives to amplify carbon sequestration. 3) Cross-regional collaboration: Establish a unified governance platform to harmonize policies, data sharing, and carbon trading mechanisms across administrative boundaries. This research provides scientific support for the low-carbon transformation of the Demonstration Zone and offers innovative insights and practical guidance for precise carbon storage evaluation and management at the regional scale.