绿美肇庆生态建设下公益林质量精准提升的碳汇成效OA

To evaluate the carbon sequestration effectiveness of the precision improvement of ecological public welfare forests under the Green and Beautiful Zhaoqing Ecological Construction,this study systematically analyzed the spatiotemporal evolution of carbon stocks in the city's ecological public welfare forests based on data from the second-class forest resource inventory of Zhaoqing City from 2021 to 2024.The results show that before the implementation of the project in 2022,the city's carbon sequestration exhibited a natural growth trend,with an average annual increase in total standing volume of 4.84%and an average annual increase in CO2 uptake per hectare of less than 1.5%.After the implementation of precision improvement measures such as mid-and young-aged forest tending and degraded forest restoration in 2022,carbon sequestration capacity steadily increased.The average annual growth rate of CO2 uptake per hectare reached up to 5.7%,and total standing volume increased from 20.94 million m3 in 2022 to 22.77 million m3 in 2024,representing an average annual increase of 4.30%.The spatial pattern of carbon sequestration is characterized by notable unevenness,with strong performance in the north,weak performance in the south,and prominent cores.Guangning,Huaiji,and Fengkai form the core carbon sequestration areas.Among these,Fengkai showed the most significant increase,with cumulative biomass per hectare growing by 11.40%from 2022 to 2024,accounting for 72.4%of the total increase over the four-year period.In contrast,Gaoyao District consistently exhibited low carbon density,while Duanzhou and Dinghu Districts faced constraints in carbon sequestration potential due to limited availability of urban land.In terms of age structure,middle-aged and near-mature forests showed steady increases in standing volume and became the main sources of carbon sequestration.However,young forests in Dinghu and Gaoyao experienced slow or even negative growth.Meanwhile,in Huaiji and Deqing,over-mature forests face the risk of declining ecological functions due to natural succession.Additionally,economic forests within the public welfare forests have persistently weak ecological service functions,resulting in insufficient carbon sequestration reserves.Future efforts in Zhaoqing should focus on optimizing forest age structure,strengthening the tending and management of young forests,scientifically promoting the regeneration and transformation of over-mature forests,and imple-menting region-specific and forest-type-specific precision improvements to forest quality.These measures will provide long-term support for the sustainable advancement of the Green and Beautiful Zhaoqing initiative.