Floristic Diversity, Community Composition and Structure in Nanda Devi National Park After Prohibition of Human Activities, Western Himalaya, India

The present study was carried out to assess floristic diversity, community composition and regeneration status of different forests in Nanda Devi National Park after prohibition of human activities in 1983 with a view to understand the impact of ban, and provide a basis for assessing subsequent changes on plant diversity and composition. The comparison of the present study with the earlier studies conducted in 1993 and 2003, indicated positive changes on plant diversity, forest composition and ecological conditions of the National Park. A total of 409 taxa belonging to 203 genera and 71 families (377 Angiosperms, 7 Gymnosperms and 25 Pteridophytes) were documented from the National Park. Two types of forest communities, i.e. Betula utilis along timberline, and mixed forest of Abies spectabilis with B. utilis form the dominant forests inside the National Park. Proportionate distribution of individuals in seedling, sapling and tree layers showed considerable variation in the population structure of different communities. Maximum species richness was observed in Dibrugheta (128) followed by Dharansi (43) and Sarsopatal (34) among the studied alpine meadows of this National Park. The present results could be a pilot to strengthen conservation measures across the Protected Area Network by understanding the impact of the ban on anthropogenic activities, and is also useful for future assessment of floristic diversity and forest composition in the National Park.