Role of woody plants in carbon sequestration: evidence from Sulula Mofa Forest, Northern Ethiopia

Forests are vital for maintaining the global carbon balance and mitigating climate change by sequestering CO₂ and storing organic carbon, contributing to sustainable development. However, Ethiopia lacks national-level carbon inventories, monitoring systems, and databanks to enhance carbon sequestration. This study assessed the carbon stock potential along altitudinal, slope, and aspect gradients in the Sulula Mofa Dry Afro-Montane Forest. Using stratified random sampling, 42 plots (400 m² each) were established. A total of 210 subplots (1 m × 1 m; 1 m²) were established within the main plots for soil and litter sampling. Equal amounts of soil and litter materials were collected from the subplots and separately homogenized to form composite samples of approximately 100 g each. Tree biomass was estimated using nondestructive allometric models, while organic carbon in litter and soil was analyzed in the laboratory. The results indicate that the Sulula Mofa Forest has substantial potential for carbon storage and climate change mitigation. The total carbon stock of the forest was estimated at 933.9 t ha⁻¹, corresponding to a CO₂ sequestration potential of 3,427.43 t ha⁻¹. Among the carbon pools, the tree biomass pool contributed the largest share (658.55 t ha⁻¹), followed by the soil pool (188.02 t ha⁻¹) and litter pool (87.33 t ha⁻¹), demonstrating the dominant role of woody vegetation in carbon accumulation. A small number of species contributed disproportionately to carbon storage, with 91.15% of the total carbon stock concentrated in ten woody species, particularly Ficus sur, Juniperus procera, Cupressus lusitanica, Acacia abyssinica, and Cordia africana. Spatial variation in carbon stocks was also observed, with higher values recorded in the western (246.09 t ha⁻¹) and southern (195.9 t ha⁻¹) sections, as well as at middle and upper altitudinal ranges. These findings highlight the ecological importance of Sulula Mofa Forest as a significant carbon sink and emphasize the need for effective conservation and sustainable management strategies to maintain and enhance its role in climate change mitigation.