Woody carbon stock estimation and factors affecting their storage in Munessa forest, Southern Ethiopia

Abstract

This study aims to assess the woody species carbon stock in the Munessa dry Afromontane forest and its variations within plant community types, as well as altitudinal, slope, and aspect gradients. A systematic sampling technique was used to acquire vegetation data. At a 100-m altitudinal drop, five transect lines were established. Ten quadrats were laid on each transect line (total 50 quadrants) at 200-m distance intervals. The woody carbon was estimated using an appropriate allometric equation formulated for tropical forests. The data was analyzed using one-way ANOVA in R software. The results show that the total woody carbon stock of the Munessa forest is 210.43 t/ha. The analysis of variance revealed that woody carbon stock varied significantly along altitude, slope, and aspect gradients, whereas community types had no significant effect. Middle elevations (2367–2533 m above sea level (m.a.s.l.)), lower slopes (0–13%), and west-facing aspects had the highest mean carbon stock. The Podocarpus falcatus–Croton macrostachyus community type also contributed a higher woody carbon stock since larger tree size classes and older trees are dominant. Overall, the carbon sequestration potential of woody species in the studied forest is strongly associated with environmental variables. Furthermore, the uneven distribution of species with larger diameter at breast height (DBH) in the studied forest might be linked to anthropogenic factors, as the current forest growth indicates characteristics of a secondary forest. Therefore, the present study suggests developing and implementing a sustainable forest management strategy particularly prioritizing middle elevation, lower slope, and west aspects of the forest to maximize the forest’s carbon sequestration capacity.