Tree Diversity Assessment of the Beach Forest Trail of Puerto Princesa Subterranean River National Park, Palawan, Philippines

Abstract

The tree species diversity and edaphic factors of the beach forest trail of Puerto Princesa
Subterranean River National Park (PPSRNP) were assessed in this study. A modification of
the Point Center Quadrat Method (PCQM) was employed for the sampling of the tree
species. The importance value of each family and tree species was computed and the
species richness and diversity of the site were measured using Shannon-Wiener, Simpson's
and Margalef's indices. Soil samples were also taken to give an ecological description of the
soil along the trail. The trail had two zones, the true beach forest and the ecotone, designated
based on the combined results of soil analysis and floral composition of the areas. The most
important family was Calophyllaceae and the most important species was Calophyllum
inophyllum. This species can survive in the beach forest despite the high leaching of the
nutrients in the soil. The high species richness and diversity (Shannon-Wiener Index of
Diversity - 1.812, Simpson's Diversity Index - 0.014, and Margalef's Index 36.112) at the site
were attributed to the relatively low level of disturbance at the site as well as the edge effect
since the beach forest borders with the mangrove and lowland forests.

Key words: tree diversity, tropical beach forest, Palawan, edge effect, ecotone, point-center
quarter method