Plant species composition, richness and diversity in different agroforestry practices of Moshi rural district, Northern Tanzania

Agroforestry practices (AFPs) have the potential to improve species composition and the ecological integrity of various landscapes. However, site-specific studies on the role of AFPs in enhancing plant species composition, richness, and diversity are scarce. This study aimed to determine variations in useful plant species composition and diversity across five agroforestry practices: Boundary Planting Agroforestry Practice (BAP), Multiple Woody Perennial Agroforestry Practice (MWPAP), Agrosilvopastoral Practice (ASP), Coffee Intercropped Agroforestry Practice (CIAP), and Mixed Intercropping Agroforestry Practice (MAP). A 10 × 10 m plot size was used to assess plant species composition and richness. Four plant species life forms were identified: trees, shrubs, climbers, and herbs. Variations in plant species composition and diversity among the AFPs were statistically analysed using ANOVA in R software, while correlations between plant life forms were determined using Pearson product-moment analysis. A total of 58 tree species (61.6%), 20 shrub species (21.3%), 10 climber species (10.5%), and 6 herb species (6.6%) belonging to 40 families and 72 genera were identified. Fabaceae and Euphorbiaceae were the most represented families, with 13 and 9 species, respectively. The highest mean species richness for trees (39), shrubs (19), and herbs (6) was recorded in ASP, while the highest mean climber species richness (10) was observed in CIAP. MAP exhibited the highest mean diversity for tree and herb species, whereas shrub and climber species diversity was highest in MWPAP and CIAP, respectively. Tree, shrub, climber, and herb species richness and diversity differed significantly (p < 0.001) across all AFPs. A significant positive correlation was observed between the species richness in trees, shrubs, and climbers in all practices (p < 0.05). The ASP and MAP demonstrated higher potential for supporting plant species richness and diversity, as well as a greater number of plant life forms. These two systems should be prioritized for their ecological and socio-economic benefits.   Key words: Plant life forms, agroforestry practices, useful, species diversity, species richness.