Diversity and composition of tree species in agroforestry systems of specialty coffees in the Alto Mayo Valley, Peru

The Alto Mayo Valley, in the San Martín region, is one of the main specialty coffee-producing areas in the Peruvian Amazon, renowned for the high quality of its beans and for cultivation under agroforestry systems. However, there is limited information on the tree species present in these systems, which hinders the understanding of their ecological and productive importance. Therefore, the objective of this study was to evaluate the diversity and composition of tree species in these systems. Thirty-eight plots were selected, distributed across the provinces of Rioja (15) and Moyobamba (23), the latter having the largest coffee-growing area. Within each plot, a 50 m x 20 m (0.1 ha) subplot was established, where all individuals with a diameter at breast height (DBH) >10 cm were inventoried, and the composition, structure of the vegetation, and tree diversity were evaluated. In total, 882 trees were recorded, belonging to 39 families, 67 genera, and 86 species. Fabaceae and Lauraceae were the most abundant families, with 286 individuals (32%) and 87 individuals (9%), respectively. The most ecologically important species was Inga edulis Mart., both in Rioja (39.90%) and Moyobamba (41.58%). Tree diversity was intermediate and similar across provinces (Shannon ≈ 1.7; Margalef ≈ 2.2; Simpson 0.24–0.30), with high dissimilarity (Jaccard = 62%). The composition included fruit, timber, and multipurpose species, with selection geared toward utilization. Tree structure was dominated by small diameters and intermediate heights. The results show how management decisions influence the diversity and composition of trees in specialty coffee agroforestry systems.