The Taxonomy and Ecology of the Pteridophytes of Mt. Iraya and Vicinity, Batan Island, Batanes Province, Northern Philippines

Abstract

A floristic survey of the pteridophyte flora of Mt. Iraya in Batan Island, Batanes Province in the Philippines was conducted from 1990 to 1996. Species richness along an altitudinal gradient was examined, and the conservation status of the taxa determined. A total of 89 species in 47 genera and 25 families were collected, representing 84% of the total species reported for the province. Of these, two are Batan island endemics, eight are Philippine endemics, and eight with strong eastern Asiatic affinities have the Batanes populations representing the southern or eastern limit of their ranges. The present study adds one new genus record for the Philippines, Phegopteris Holub., one recently described species, Goniophlebium coadunatum Barcelona et Price, and fifteen new species records for the province. The lowland grassland (0–200 m) and the lower montane forest (500–900 m) are the richest in species composition (38 spp. each), the latter also has the largest proportion of endemic taxa. Only three species were recorded from the summit. Seven previously reported species were not recollected.