Floral Diversity in a Coffee-based Agroforestry System in Abra, Philippines

Agroforestry systems play a vital role in conserving biodiversity while sustaining livelihoods in upland agricultural landscapes, yet their contribution to floral diversity remains underexplored in many parts of the Philippines. This study, conducted in Licuan-Baay, Abra, examined a coffee-based agroforestry system, focusing on plant species composition, importance values, richness, diversity, and evenness. Plant species were categorized by diameter and assessed for conservation status. Stratified sampling utilized 20m x 20m plots with nested 10m x 10m subplots. Larger plots analyzed trees with diameters ≥10cm, while saplings (1-9 cm DBH) were studied in smaller subplots. A total of 93 trees representing 21 native species were recorded, with small trees (10-30 cm DBH) being the most prevalent. Among trees, Shorea contorta showed the highest relative density, dominance, and importance value, while Coffea canephora led in these metrics among saplings. The Shannon Diversity Index reflected moderate diversity (2.35) for tree plots and low diversity (2.04) for sapling plots, alongside high evenness values of 1.58 for trees and 1.84 for saplings. The presence of several threatened species, including critically endangered Agathis philippinensis, endangered Anisoptera thurifera, vulnerable species like Shorea negrosensis and Nephelium lappaceum, and the near-threatened Canarium luzonicum, emphasizes the urgency of conservation in the area. Findings highlight that coffee cultivation supports biodiversity and coexists with native species, underscoring the importance of preserving the site and its threatened flora.