Effects of coffee management intensification in natural forests on woody species diversity and structure in Yayo district, south western Ethiopia

This study was conducted to evaluate the difference between woody species diversity, structure and similarity in natural forests and adjacent coffee farms in Yayo district, southwestern Ethiopia. Vegetation data were collected from both land use systems using transects walk lines. The Shannon, Simpson’s, similarity and importance values index were analyzed using SPSS version 20 software. The result revealed 64 woody species belongs to 31 families from both land uses. Moraceae had the most diverse family having each 5 and 8 species in coffee farms and natural forests respectively. The species richness was higher in natural forests (54) than coffee farms (38). Coffea arabica (42.85%) and Celtis africana (21.14%) those frequently occurred had the highest importance value indices in coffee farms and natural forests respectively. Of total species recorded, 28 (43.75%) are common, 26 (40.63%) and 10 (15.62%) were unique to natural forests and coffee farms respectively. The highest number of woody plants per hectare were distributed in diameter at breast height 5-10cm having 1250 ha−1 (64.10%) in natural forests and 471 ha−1 (72.33 %) in coffee farms. The total basal areas were 364.44 and 669.84 m2ha−1 in coffee farms and natural forests respectively. The result indicated that planting coffee in natural forests with intensified management system causes significant differences on the overall woody species diversity i.e. the structure, composition and regeneration rates of the forest. Therefore, it is recommended to plant coffees in home garden and open lands with planting multipurpose shade trees rather than cultivating it in natural forests.