Unraveling the effects of land use change on carbon balance: a systematic study in the Beijing-Tianjin-Hebei region, China
Zhuoran Ma, Jianjun Wu, Huicai Yang, Jianhua Yang, Jianhang Zhang
Abstract
With the advancement of economic development, urbanization, and ecological civilization initiatives, land use patterns are undergoing significant changes. The allocation of land resources among urban areas, croplands, and forest/grass ecosystems has substantial impacts on regional carbon balance. Vegetation carbon sequestration and anthropogenic carbon emissions are two critical components of carbon balance, and their distinct formation mechanisms suggest differing roles of land use in each process. However, few studies have systematically explored the impact of land use on carbon balance from both composite and component perspectives. In this study, a dual-layered indicator system is employed to quantify land use and carbon balance. Based on this, a case study is conducted in the Beijing-Tianjin-Hebei (BTH) region following a “characteristic-relationship-strategy” analytical framework. The results reveal that: (1) From 2000 to 2020, the intensity of land development driven by human activities increased across BTH, primarily due to the conversion of cropland to urban areas. In contrast, land use intensity declined in the northwestern and northern areas, where cropland was converted to natural vegetation such as forests and grasslands. (2) BTH exhibited a carbon deficit, with carbon emissions exceeding sequestration. However, since 2011, the increasing trend in this deficit has gradually slowed and eventually reversed. (3) Overall, land use changes had a greater impact on vegetation carbon sequestration than on anthropogenic emissions. Specifically, natural vegetation restoration contributed significantly to increased sequestration; croplands in the plains demonstrated considerable carbon sequestration potential; and urban expansion led to substantial carbon emissions. Urban carbon reduction is the key to improving regional carbon balance. (4) Due to differences in natural endowment, economic development levels, and strategic positioning among BTH cities, the spatial association and temporal response of land and carbon variables exhibit strong spatial heterogeneity. Tailored and region-specific strategies, supported by coordinated development and scientific land management, are essential to promote low-carbon development.