Abstract: Based on the framework of “forest growth + forest logging + forest planting + forest quality improvement”, we forecasted biomass carbon sequestration of arbor forests in the Yangtze River Delta region and their contributions to the carbon peaking and carbon neutrality goals. This study aimed to provide insights into the development of forest management plans and policies related to the carbon peaking and carbon neutrality goals in the Yangtze River Delta region. Drawing from the 9th national forest inventory data (2014-2018), we compiled biomass conversion parameters and carbon content intervals for dominant tree species (groups) through a synthesis of literature. The volume-age regression model for each dominant tree species (groups) in each province of the Yangtze River Delta region was used to predict carbon storage of arbor forests. Carbon sequestration was estimated by assessing the difference in carbon storage between two periods in the Yangtze River Delta region in 2030 and 2060, along with their contribution rates to the carbon peaking and carbon neutrality goals. The results showed that: (1) By 2030, carbon storage of arbor forests in the Yangtze River Delta region is projected to reach 343.46 Tg, with an increase of 141.79 Tg compared to the baseline year. This increase comprises a reduction of 25.88 Tg due to forest logging, an increase of 12.96 Tg from afforestation (growth + quality improvement), and a rise of 55.94 Tg from forest quality improvement (existing arbor forests). The mean annual carbon sequestration is 9.01 Tg·a^-1, equivalent to absorbing 33.04 Tg of CO₂. The contribution rate to carbon peaking in the Yangtze River Delta region by 2030 is projected to be 1.81%. (2) By 2060, carbon storage of arbor forests would reach 573.55 Tg, with a further increase of 230.09 Tg from 2030. This includes a reduction of 13.46 Tg from forest logging, an increase of 25.77 Tg from afforestation (growth + quality improvement), and an augmentation of 72.76 Tg from forest quality improvement (existing arbor forests). The mean annual carbon sequestration is estimated as 7.67 Tg·a^-1, equivalent to absorbing 28.12 Tg of CO₂. The contribution rate to carbon neutrality in the Yangtze River Delta region by 2060 is projected to be 9.53%. In summary, the carbon sink in arbor forests in the Yangtze River Delta region is a stable and efficient pathway for carbon sequestration. By gradually contributing to the achievement of the carbon peaking and carbon neutrality goals, it serves as a valuable forest carbon pool. However, there are challenges such as relatively low overall carbon sequestration, uneven distribution, and untapped carbon sequestration potential. In the future, promoting sustainable forest management practices to facilitate forest regeneration, conducting activities to improve forest quality and enhance carbon sequestration, continuously promoting the afforestation of high carbon-fixing tree species, and transitioning from low carbon density plantations to mixed forests with higher carbon density will be key to enhancing forest carbon sequestration capacity. These efforts will contribute to the realization of the carbon peaking and neutrality goals in the Yangtze River Delta region.

Key words: the Yangtze River Delta region, arbor forest, biomass carbon sink, carbon peaking and carbon neutrality goals