Diversity, Structure and Composition of Forest Communities in Hirb and Shoja Catchments of Himachal Pradesh, North West Himalaya, India

Forest ecosystems are critical for biodiversity, watershed protection and livelihoods of indigenous and rural people. High biodiversity favours ecological stability, where as accelerating species loss could lead to collapse of the ecosystem. The biodiversity of Himachal Pradesh is also depleting fast due to heavy anthropogenic pressure and climate change. It’s the need of the hour to assess the vegetation qualitatively and quantitatively to know the actual status of the vegetation. Therefore, present study has been conducted to assess the structure, composition and status of the forest vegetation in Hirb and Shoja Catchments of Himachal Pradesh. 93 woody species were recorded in the 65 sampled between 2000-3650 m amsl. Twenty four forest communities (Trees: 18 and Shrubs: 06) were identified based on Importance Value Index (IVI) for trees and relative density for shrubs. Total tree density ranged from 60.0-1060.0 Ind ha-1, Total Basal Area (TBA), 0.20-83.99 m2 ha-1, total shrub density, 630.0-2470.0 Ind ha-1 and total herb density, 56.3-164.2 Ind m-2. The species diversity for trees, shrubs and herbs ranged from 0-1.749, 0.917-2.948 and 2.74-4.13, respectively. All these ecological values were comparable with the values reported from other parts of the state and Indian Himalayan Region. The regeneration pattern of tree species within different communities showed different trends. The utilization pattern of the vegetation of the area showed high anthropogenic pressure. Therefore, frequent monitoring of the vegetation is required, so that adequate management plan could be developed and implemented for the conservation of vegetation.