Diversity of woody species in traditional agroforestry practices in Wondo district, south-central Ethiopia

Woody species are very important components of agroforestry as they play multiple roles in the system. Therefore, this study was conducted to assess woody species diversity within households' farms. Stratified random sampling was employed for the study, where households were stratified via wealth ranking. Accordingly, the farm plots of 54 households were subjected to a complete on-farm woody species inventory and identification. Consequently, the diameter at breast height (DBH) of all woody species ≥5 cm was recorded. Therefore, important value and diversity indices, density, dominance, and frequency were computed and estimated. A total of 90 woody species belonging to 80 genera and 42 families were recorded in the area. Out of the total species recorded, 2 (2.22%), 32 (35.56%), and 56 (62.22%) were endemic, exotic, and indigenous, respectively. The family Fabaceae had the highest number of woody species represented by 16. The most frequent species were Cordia africana Lam., followed by Eucalyptus camadulensis Dehnh., Persia americana Mill., Mellitia ferruginea (Hochst.) Bak., and Croton macrostachyus Del. which occurred in 87.03%, 81.48%, 81.48%, 75.92%, 72.2% of sampled farms, respectively. Besides, the top five species which had the highest important value index were Eucalyptus camaldulensis (57.38), Cordia africana (30.45), Persea americana (27.36), Mellitia ferruginea (17.28), and Croton macrostachyus (14.59). Shannon Weiner index (H') and Shannon evenness values of the study area were 2.17 and 0.80, respectively. Species richness and Shannon index values were statically significant (p < 0.05) among the three wealth categories. Besides, the Sorensen similarity index for studied villages ranged from 33.7% - to 77.5%. Generally, the current study showed that the agroforestry system plays a remarkable role in conserving woody species diversity. However, extension services on management practices for species and stands, increasing seedling accesses, and survival rates of species are very impotent to making agroforestry practices sustainable.