Species Composition and Diversity of Associated Plants under the Canopy of Large Mahogany Trees in Loboc-Bilar Mahogany Plantation, Bohol, Philippines

Abstract

The Loboc-Bilar Mahogany Plantation is a well-known tourist attraction in Bohol, Philippines. Its 250-m long green tunnel-like scenery and cold microclimate fascinate many tourists to drop by and take photographs. Canopy of large-sized mahogany trees provide cover not only to visitors but also to a variant of shade-tolerant understory plants and ground vegetion. This study was conducted to investigate the species composition and diversity of a variety of plant species associated to mahogany trees. Random sampling method was applied in conjunction with Geographic Information System (GIS) to spatially distribute sampling plots in the research area. A hundred nested plots, each with a dimension of 20m x 20m, were established one-by-one at the coordinates generated by the GIS software. Plants were identified to species level and morphometrics (diameter at breast height and total height) were obtained for abundance (importance value) and diversity calculation. Results revealed that there were 135 plant species distributed to 92 trees, 16 shrubs, 14 herbs, 8 vines, 4 ferns and lycopods, and 1 liana. Species diversity was found to be low for large trees (>30 cm DBH) and very high for both pole-size trees and saplings (<30 cm DBH)  and understory plants and ground vegetation given Shannon-Weiner values of 2.33, 3.74 and 3.87, respectively. The Loboc-Bilar Mahogany Plantation harbors a wide variety of plants particularly those with DBH lower than 30 cm.