Carbon Storage Changes and Multi-Scenario Projections in the Yellow River Delta High-Efficiency Ecological Economic Zone Based on the PLUS–InVEST Model

Against the backdrop of global climate warming, accurately assessing changes in regional ecosystem carbon stocks and their responses to future scenarios is crucial for achieving the “dual carbon” goals. This study selects the Yellow River Delta High-Efficiency Ecological Economic Zone as the research area, utilizing land-use data from 2000, 2010, and 2020. By employing the PLUS–InVEST model, the spatiotemporal evolution of carbon stocks was investigated at the county scale, and land-use patterns and carbon stock distributions in 2030 were predicted under three scenarios: natural development, urban expansion, and ecological conservation. Results show that total carbon stocks declined between 2000 and 2020. The northeastern coastal region, characterized by concentrated water bodies and construction land, experienced significant reductions in carbon storage. Meanwhile, parts of Zouping City in the southwest and Laizhou City in the east, dominated by forestlands, emerged as high-carbon stock zones. Moreover, carbon stocks exhibit marked spatial heterogeneity and temporal dynamics at the county level, with Laizhou, Shouguang, and Wudi ranking among the highest in total carbon storage, while Qingyun, Yangxin, and Gaoqing remained consistently low. Scenario predictions further reveal substantial differences in carbon stock impacts across development pathways. Specifically, under natural development, carbon stocks continue their historical downward trend, with carbon sources primarily located along the coast, resulting in an overall net carbon source. Urban development amplifies this trend, expanding carbon source areas and intensifying the net carbon source status. In contrast, ecological conservation effectively mitigates carbon loss, maintaining overall carbon storage stability while generating localized carbon sink patches within urban centers. The integrated technical framework developed in this study not only provides a quantifiable and verifiable decision-support tool for territorial spatial governance and coordinated implementation of the dual carbon goals in the Yellow River Delta, but also offers a scalable methodological model for evaluating ecosystem carbon sequestration potential and adaptive management in China’s coastal ecological regions.