Patterns in plant species diversity along the altitudinal gradient in Dhauladhar mountain range of the North-West Himalaya in India

Abstract

The objective of the present study was to understand the patterns in plant species diversity along the altitudinal gradient in Dhauladhar mountain range of the Indian Himalayas. Nested plot method was employed for sampling trees, shrubs and herbs along the elevations from sub-tropical forests to sub-alpine forests, and Shannon-Weiner diversity index was used for calculation of plant species diversity. A total of 10 forest communities were identified, of which the highest number of forest communities and woody species diversity were found in the temperate forests. Though, there are multiple ecological factors and their combinations which determine the distribution and diversity of plant species in an ecosystem, the present study reveals that elevation is one of the major abiotic factors in the Himalayan mountains, which determines the establishment and distribution of various forest communities and species diversity. Along an altitudinal gradient there was a hump-shaped curve in the species diversity of woody plant species whereas the species diversity of herbaceous species increased with elevations from sub-tropical to sub-alpine forests. This fact needs to be employed while making policies and planning for the sustainability of forests along the altitudinal gradients in the mountains.