A botanical inventory of a submontane tropical rainforest on Negros Island, Philippines

This paper provides a botanical inventory of a forest community in the North Negros Forest Reserve that is disproportionately valuable from a conservation perspective. The forest fragment is one of the last remaining wet tropical rainforest ecosystems in the biogeographic region of the West Visayas and an important refuge for a large number of endemic species. Using standard methods of the Philippine Plant Inventory Project we described the structure and composition of this little known forest type in the transition zone between lowland and lower montane forest. A 1 ha inventory plot 500×20m in size was established and all trees of 10cm DBH or greater were measured and permanently labeled. Subsequently, fertile specimens were collected over a period of 18 months. We found 645 individuals belonging to 92 species, 54 genera and 39 families with a combined basal area of 58.8m² and an average canopy height of 30m. This community was not dominated by dipterocarps. Species of Lauraceae, Burseraceae, Sapotaceae and Icainaceae were equally or more important. Diversity measured as Shannon–Wiener index (5.59), equitability index (0.86) and Simpson index (0.032) was high, and no single family or species dominated the plot.