Rapid assessment of epiphytic pteridophyte biodiversity in Mt. Apo Natural Park, North Cotabato Province, Philippines: a comparison of disturbed and undisturbed forests

Pteridophytes are potential indicators of climate change and environmental disturbances because of their sensitivity to the changes in the environment such as sunlight intensities and humidity levels. The study was conducted to document the species and compare the diversity of epiphytic pteridophytes in two sites–the undisturbed and disturbed areas of Mt. Apo Natural Park, North Cotabato Province in the Philippines. In each site, four stations were established, each with four 20 m × 20 m plots that are at least 20 m apart from each other. Between stations, at least 100 m was maintained. In this study, 102 species of epiphytic pteridophytes belonging to 33 genera and 14 families were identified. Seven species are lycophytes and 95 species are ferns. The number of species recorded represents 10 % of all species of pteridophytes in the Philippines. Polypodiaceae was the most dominant family consisting of 13 genera and 33 species. Among these, Prosaptia was the largest genus represented by nine species followed by Selliguea with five species. Based on the Species Importance Value (SIV), Lindsaea pulchella was the most abundant species in the area studied. Abundance of epiphytic pteridophytes vary between two sites but other parameters such as species richness, evenness, Shannon-Weiner and Simpson diversity indices showed no significant differences. There were three main assemblages of epiphytic pteridophytes based on species composition with 50% overall similarity. Of the 102 species identified, 11 were threatened which represent 6.08% of the total threatened pteridophytes of the Philippines. Noteworthy is the new species record of Asplenium beccarianum for the Philippines. Unique composition of epiphytic pteridophytes was evident and the results showed that Mt. Apo is an important location for the conservation of these communities. KEYWORDS: abundance, Asplenium beccarianum, conservation, phorophtye, epiphyte