Spatio-temporal variations of the land-use-related carbon budget in Southeast China: the evidence of Fujian province

Abstract The attainment of a regionally balanced carbon budget is fundamental for the realization of carbon neutrality. This study involved the quantification of the carbon budget related to land use across Southeast China from 2005 to 2020, which was achieved through the calculation of both carbon emissions and carbon sinks. Subsequently, we scrutinized the mechanisms driving the observed dynamic changes in the carbon budget, pinpointed the impact of land-use efficiency (LUE) on the carbon budget, and proposed sustainable spatial planning and management strategies for diverse functional areas at the county level. The core findings are as follows: The dynamics of the carbon budget were spatially heterogeneous, characterized by a gradual increase in carbon emissions over time, while carbon sinks remained relatively constant. The Gini coefficient (G) manifested a gradual increase throughout the study period, reflecting an imbalanced evolution between carbon sinks and emissions. There was also an observable imbalance in the distribution of the carbon ecological carrying coefficient between coastal and inland regions. Land-use-related carbon emissions demonstrated a substantial spatial spillover effect, whereas a weak spatial spillover effect was noted in land-use-related carbon sinks. The correlation between LUE and the carbon budget varied significantly across different functional areas, as the driving effects of LUE displayed remarkable spatial heterogeneity. A quantification of the spatio-temporal alterations and the driving mechanisms behind the carbon budget can aid in the advancement of urban sustainability and regional carbon neutrality.