Quantifying Ecosystem Carbon Stocks and Various Carbon Pools Across Different Zones of Biosphere Reserves Is Essential for Informing Policy Decisions and Advancing Scientific Research on Forest Ecosystems’ Role in Climate Change Mitigation and Ecolog

Quantifying ecosystem carbon stocks and various carbon pools across different zones of biosphere reserves is essential for informing policy decisions and advancing scientific research on forest ecosystems' role in climate change mitigation and ecological conservation. Previous carbon stock assessments in the Yayu Coffee Forest Biosphere Reserve (YCFBR) and other moist Afromontane forests primarily focused on disturbance and elevation gradients. However, there is limited data for carbon stock assessments across zonation and zonation effects. Therefore, this study aims to quantifying carbon stock across the three zones of YCFBR in Southwest Ethiopia, i.e., the core zone, buffer and transitional zones. Vegetation data were collected using various plot sizes across the three zones for the core, buffer, and transition zones. Above-ground carbon (AGC) was determined from above-ground biomass (AGB), while below-ground carbon (BGC) was estimated as 27% of the AGC, and then extrapolated to megagrams of carbon per hectare (Mg C ha⁻¹). Litter and soil samples were also collected and analyzed. To evaluate the contributions of species diversity and structural attributes to carbon storage, a correlation analysis was performed. Results indicate significant differences in AGC, BGC, soil organic carbon (SOC), litter carbon (LC), and total carbon (TC) among the core, buffer, and transitional zones. The core zone exhibited the highest AGC and SOC, suggesting superior carbon sequestration, while the buffer zone had the highest LC stock. Overall, TC was highest in the core zone compared to buffer and transitional zones. Additionally, species diversity and stand structure were positively associated with carbon storage, highlighting the importance of preserving diverse and structurally complex forests for enhancing carbon storage and climate change mitigation. Future research should focus on litter decomposition rates across these zones to better understand the relationship between litter carbon stocks and SOC contributions.