DIVERSITY OF PTERIDOPHYTES ALONG THE ALTITUDINAL GRADIENT IN PALPA DISTRICT, WESTERN NEPAL

Abstract

The present study aims to study the diversity of pteridophytes along the altitudinal gradient in Northern and Southern aspects of Palpa district, Western Nepal. A total of 126 quadrats were laid, with 63 in a Southern and 63 in a Northern aspect and size of plot was 5m×5m for vegetation sampling. 7 plots were laid along horizontal transect at every 100m altitude, with a 20 m differences between each sample plots. Altogether 42 species of pteridophytes belonging to 12 families and 24 genera were recorded in the study area. Pteridaceae was found as largest family on the basis of number of species. Highest species richness was observed at an altitude of 800 m on both aspects. Species diversity was found maximum in the Northern aspect because of the moist habitat than in comparison to Southern aspect. Pteidophytes species like Selaginella fulcrata, Thelypteris dentata, Selaginella pallida were dominant in the Northern aspect, and Selaginella fulcrata, Aleuritopteris bicolor, Dryopteris cochleata, Aleuritopteris dealbata were dominant in southern aspect. The pteridophytes species richness pattern was decline with increase in elevation at both aspects in this study. The mean species richness across elevations in both aspects was also shown statistically significant (p< 0.01) based on one-way ANOVA. Furthermore, 15 species were commonly used by the locals for fodder, medicine, also as vegetables.