Diversity of herbaceous pteridophytes in four long term ecological research sites in Mindanao, Philippines

A study on the diversity of herbaceous pteridophytes was conducted in the four Mindanao long term ecological research (LTER) sites, viz. Mt. Apo (North Cotabato), Mt. Hamiguitan (Davao Oriental), Mt. Kitanglad (Bukidnon) and Mt. Malindang (Misamis Occidental). Complete enumeration of the herbaceous pteridophytes in the one-hectare plot was done in each of the four sites. Descriptive analysis of diversity and similarity between sites were done. The study revealed a total of 130 species of pteridophytes in 66 genera and 24 families were recorded from the four LTER sites. Among the four sites, Mt. Kitanglad had the highest species richness (S = 56), followed by Mt. Apo (54 species), Mt. Malindang (52 species) and Mt. Hamiguitan with the least number of species (27). Shannon index of diversity showed that Mt. Malindang had the highest among the four sites (H' = 1.41), followed by Mt. Kitanglad (H' = 1.37), Mt. Apo (H' = 1.26) and the least by Mt. Hamiguitan (H'= 0.91). Similarity indices between and among sites were relatively low since most of the percentage values of concordant species fell below the mean value of 50%. All these baseline data are important for the regular, continuous monitoring of these permanent plots for long term ecological research.