Comparative study of woody species diversity, composition, structure and aboveground biomass carbon stock of Jello Muktar Dry Afromontane Forest with adjacent agroforestry, Southeastern Ethiopia

Reduction in plant species diversity, influences the potential of carbon stocks in a given land use. The forest are disappearing at an alarming rate in the tropics, so the role of agroforestry (AF) as a conservation tool and carbon sequestration needs to be further explored by comparing with forests. Thus, the aims of this study was to evaluate and compare woody species diversity, Composition, Structure and above ground biomass (AGB) carbon stock of Jello Muktar Dry Afromontane forest (JMF) and its adjacent AF. Dataset from forest inventory (n = 30), undertaken in JMF was used. For AF forty sample plots with 20 m × 20 m were sampled with stratified systematic sampling techniques. Woody species diversity analysis were carried out using Shannon Weiner Diversity index (H'), Simpson diversity (D) and Evenness index (J) whereas, similarity was carried out using Sørensen coefficient of similarity (Ss) index respectively. General and species or site specific allometric equations were used to calculate the AGB. A total of 74 woody species belonging to 47 families were recorded across the two land uses. The species similarity index between the two studied land uses was low (17.65%). The independent samples test indicated higher values of H' (3.20), D (0.95), and J (0.95) indices in JMF compared to the adjacent AF values of H' (2.09), D (0.83), and J (0.80). However, no statistically significant difference (p < 0.05) was observed for the H' index between JMF and AF. AGB carbon stock was significantly (p<0.05) higher in JMF than and its adjacent AF. There was a positive relationship between diversity and carbon stock in the two studied land uses. The study revealed that preserving forests for both biodiversity and climate change mitigation is vital along with the complementary role AF to buffer the forest.