Land use profoundly impacts the sustainable development of the ecological environment. Optimizing land use patterns is a vital approach to mitigate climate change and achieve carbon neutrality. Using Shandong Province as a case study, this research evaluates the impacts of land use and land cover change (LUCC) on regional carbon storage and emissions. Employing a coupled PLUS–InVEST–GM(1,1) model, simulations were conducted for scenarios including the natural scenario (NS), cropland protection scenario (CPS), high-speed development scenario (HDS), and low-carbon scenario (LCS), to assess LUCC and changes in carbon storage and emissions from 2030 to 2060 under these scenarios. The findings indicate that due to the expansion of construction land and significant declines in arable and grassland areas, carbon emissions increased by 40,436.44 × 10⁴ t over a 20-year period, while carbon storage decreased by 4881.13 × 10⁴ t. Notably, forests contributed the most to carbon sequestration, while construction land emerged as the primary source of carbon emissions. Simulating four scenarios demonstrates that measures such as protecting cropland, expanding forest, grassland, and aquatic areas, controlling construction land expansion, and promoting intensive development positively affect emission reductions and carbon sequestration in Shandong. These findings underscore the importance of rational planning of land use patterns, which can enhance contributions to carbon neutrality by harmonizing the relationships among cropland protection, ecological conservation, and economic development.

The identification of supply and demand areas for ecosystem services (ES) and the simulation of ES flows are essential for optimizing ESs to achieve socio-economic sustainable development. However, the selection of investigation methods and simulation model remains a persistent challenge. This study selected the Yellow River Delta High-Efficiency Eco-Economic Zone in China as the case study area and assessed the habitat quality and carbon sequestration services for 2000, 2010, and 2020. The quantile regression method was employed to quantify the impacts of land use structure on balancing the supply and demand of ESs. The minimum cumulative resistance model, circuit corridor model, and wind direction model were utilized to analyze changes in flux and flow direction of ESs’ supply and demand. The results demonstrated that the following: (1) the supply of ESs generally increased, with a significant rise in demand for carbon sequestration service and a declining trend in habitat quality service demand. (2) A clear spatial mismatch existed between the supply and demand of ESs. (3) The impact of land use structure on the balance of ES supply and demand is complex. (4) Habitat quality and carbon sequestration services exhibited distinct spatial clustering patterns. (5) The flow patterns of habitat quality service were characterized by specific supply and demand areas, with corridors and pinch points indicating the flow paths and potential barriers; not all demand areas for carbon sequestration service can be satisfied due to variations in service levels and geographical distance. The innovation of this study lies in the following aspects: (1) it acknowledges the uniqueness of ecosystem services, with a focus on assessing habitat quality and carbon sequestration services; (2) it precisely quantifies the flow of ecosystem services, analyzes the spatial dynamics of service flows, and investigates the impact of changes in land-use structure on these flows; (3) it strengthens the correlation between the supply and demand of ecosystem services and socio-economic activities, uncovers the contradictions between supply and demand along with their underlying causes, and proposes effective strategies for resolution. The findings can provide theoretical and methodological references for the optimization of ES.