Floral resources and taxonomic-biogeographical discoveries at Samar Island Natural Park [Philippines]

Samar, the third largest island in the Philippine archipelago, has a total land area of 13,458 sq km. Recent satellite images showed that a large portion of the remaining forest blocks on the island had long since been cleared for agriculture and from continued illegal logging activities. For Samar to be declared a natural park, Ragub (DENR-PAWB/SIBP) led a biological resource assessment of the eight watersheds making up Samar Island Natural Park (SINP), for a comprehensive database. Specifically, the status of floral resources in terms of their taxonomy, distribution, plant diversity level, potential uses, and conservation status was evaluated. The project was implemented from August 2002 to July 2003. The total plant diversity of the Samar Island Natural Park was composed of 974 species distributed in 436 genera and 131 families. As to habitat composition, the entire SINP had a total of 55 species of epiphytes, 103 ferns, 146 herbs, 76 lianas or woody vines, 56 shrubs, 165 small trees, 230 medium-sized trees, 100 large trees, 36 tree-like plants and 39 vines. The potential and/or actual economic uses of the 974 plant taxa can be broken down into 49 for cottage industry, 9 fruit crops/trees; 28 with edible fruits; 3 fiber sources; 413 landscape materials; 24 medicinal; 14 poison source; 1 shampoo source; 5 vegetables; 212 ornamentals; 1 pulp fiber source; 3 root crops; 2 spices; 19 weeds; 2 soil erosion control; 10 ecological functions; and 262 species as source of timber. The biological assessment data showed that a relatively high biodiversity level was present in each of eight watersheds and these watersheds have unique combination of ecosystems that should also be conserved wisely and managed beneficially. On floristic value, a number of new species records were made. One important taxonomic and biogeographic discovery was made in the Suribao watershed, particularly in the vicinity of Mt. Apoy in Brgy. [village] Benowangan, Borongan, Eastern Samar. Falcatifolium gruezoi de Laub., (Podocarpaceae) known locally as 'karis-karis' in Waray, 'binaton in Tagalog, and Gruezo sickle-leaf in English was discovered. Its discovery represented a new forest type termed as mixed Falcatifolium forest. This can only be found in a specific habitat type described as new under the name pseudo-peat swamp. The discovery of another species of conifer, Podocarpus rumphjii ('malakawayan', podocarpaceae) brought the total number of conifer species in Samar Island to five; with this particular species as an example of a new species record for the island. Such floral diversity presents a great potential for the ornamentals/landscape industry. The entire SINP is a broad composite of the following ecosystems: grasslands, agroforestry areas, forest-over-limestone, riparian ecosystem, lowland mixed dipterocarp forest, and mossy or cloud forest. The study highly recommends the completion at the soonest possible time of the perimeter survey of each of the eight SINP watershed. A number of special habitats that was within the buffer zone has to be marked clearly for inclusion to the respective watersheds. Likewise, plant species with special habitat requirement should be marked on the ground within and outside of the watershed perimeter. The transplanting of wildlings in appropriate localities should be made a priority particularly for sensitive and/or highly endangered taxa. The regular monitoring and evaluation of randomly chosen ecosystems within SINP is also recommended with time interval of 7 years.