Floral Composition and Diversity of Ultramafic Forests in Homonhon Island, Eastern Samar, Philippines

ID: 613 / 305

Category: Abstract

Track: Pending

Proposed Symposium Title: Floral Composition and Diversity of Ultramafic Forests in Homonhon Island, Eastern Samar, Philippines

Authors:

Roanne B. Romeroso1,2 *, Jorge Anton D. Ordas 3, Danilo N. Tandang4, 5, Ian A. Navarrete6, Cecilia B. Moran1, 3

Affiliations: 1 The Graduate School and Research Center for the Natural and Applied Sciences, University of Santo Tomas, España Boulevard, Sampaloc, 1015, Manila, Philippines 2 Department of Biology, College of Science, University of Eastern Philippines, Northern Samar, Philippines 3 Department of Biological Sciences, College of Science, University of Santo Tomas, España Boulevard, Sampaloc, 1015, Manila, Philippines 4 Botany Division, Philippine National Museum of Natural History, Padre Burgos Street, Ermita, 1000, Manila, Philippines 5 Biodiversity Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan Normal University, Taipei, 11529, Taiwan 6Department of Environmental Science, Southern Leyte State University, Hinunangan Campus, Ambacon, Southern Leyte, 6608, Philippines

Abstract:

The Philippines has suffered tremendous deforestation due to rampant anthropogenic impacts such as mining. In particular, the forests of Homonhon Island are threatened by mining activities. In this study, we assessed its ultramafic vegetation's floristic composition and diversity to initiate its conservation efforts on Homonhon Island. In five sampling areas on the island, we have documented 181 species in 148 genera and 83 families, with 176 native species. Twenty-two species are classified as threatened based on the IUCN. On the other hand, in DENR-DAO 2017-11, 38 are classified as threatened. Homonhon Island exhibits a very high species diversity overall, and the forests in Barangay Bitaugan revealed the highest species diversity among the sampled areas. Alstonia macrophylla and Terminalia surigaensis chiefly dominates the island's forests. Despite being threatened by mining, Homonhon Island's ultramafic forests exhibit a diverse floristic composition worthy of protection. It serves as a sanctuary for many of the Philippines' highly threatened species. Its local government agencies should implement strict protection and management policies to prevent further disturbance to its flora. We can anticipate this study to be used in the restoration, rehabilitation, and conservation of the remaining forest on the island.

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Key words: Philippine flora; Samar; species list; vascular plants; vegetation analysis