Natural forest coffee, semi-forest coffee, and homegarden coffee are generally seen as beneficial for biodiversity conservation, but this may not always be the case. While they are widely recognized for their biodiversity conservation values, their impact on woody species diversity, composition, and structure still remains a gap. This study examined the impact of natural forest coffee, semi-forest coffee, and homegarden coffee on woody species diversity and structure in the Yayu Coffee Forest Biosphere Reserve, Southwest Ethiopia. Three coffee production systems were considered for the study, namely homegarden coffee, semi-forest coffee, and natural forest coffee. In all, 90 sample plots were randomly selected and surveyed. A total of 27 woody species belonging to 17 families were recorded. Natural forest coffee maintains the highest structural complexity and continuous regeneration of shade trees as compared to homegarden and semi forest coffee. All diversity indices confirmed that there was significantly higher biodiversity in natural forest coffee. Structural attributes, including stem density, diameter at breast height (DBH), and basal area, were significantly greater in natural forest coffee and semi-forest coffee than in homegarden coffee ( p 0.05). Both the Jaccard and Sørensen similarity coefficients indicate a strong overlap in woody species composition between natural forest coffee and semi-forest coffee (Jaccard = 0.67 and Sørensen = 0.80). Natural forest coffee and homegarden coffee showed the lowest similarity (Jaccard = 0.38; Sørensen = 0.56), reflecting substantial differences in species composition. Rarefaction analyses confirmed adequate sampling coverage. The findings emphasize the highly significant role of natural forest coffee and semi-forest coffee for biodiversity conservation.
Mamo et al. (Sun,) studied this question.