Effects of management practices and socio-physical factors on perennial plant diversity of agroforestry systems of Gedeo landscapes, Southern Ethiopia

This study investigates the influence of agroforestry systems, management practices, and socio-physical factors on plant diversity and richness agroforestry systems of Gedeo in southern Ethiopia. It analyzed 286 sample plots (10 m × 10 m), collecting data on both woody and non-woody perennial species. Insights into management practices and socio-physical conditions were gathered through surveys, focus groups, and interviews. A total of 78 plant species were identified in the study area. The Coffee-Fruit-tree system showed the highest species richness (10 species per plot) and the highest Shannon and Simpson diversity indices. In contrast, the Coffee-Enset-tree and Enset-Tree systems had lower species richness. The study found significant differences in species diversity and abundance across elevations, with highland farms having the lowest values (p < 0.001). Plots tilled by hand once a year showed the highest diversity, richness, and abundance, while those ploughed three times a year had the lowest. Weeding once or twice a year did not significantly affect diversity indices, but weeding three times a year reduced them. Wealthier households had higher perennial plant species richness compared to middle-class and poor households. The prevalence of economically focused plants had a detrimental effect on species diversity and richness (p < 0.001), whereas selective tree removal had a positive impact on both. Increased frequency of tillage and non-selective weeding by slashing also led to reductions in species diversity and richness. Altitudinal differences had an effect on both species richness and diversity.