Plant Diversity and Vegetation Composition of Shiwalik Forests Along an Altitudinal Gradient in the Kumaun Himalaya, India

Abstract

The present study was carried out to assess the plant diversity and vegetation composition of the Shiwalik forests along the altitudinal gradient. In Sal mixed pine forest (1300–1500 m), Sal mixed broad-leaved forest (800–1000m) and Sal dominant forest (400–600 m) elevations. The sand, silt and clay ranged from 39.9 to 48.7, 45.8 to 55.6 and 4.4 to 6.1 %, respectively. Soil porosity and soil pH was 43.4 to 56.4 % and 5.3-6.0, respectively. A total of 167 plant species were reported from the studied forest sites. Of this, trees, shrubs and herbs accounted for 39, 27 and 101, respectively. The maximum tree density and basal area was 830 ind/ha and 43.9 m2/ha respectively in middle elevation. Shorea robusta was the most dominant species with IVI of 77.9 and 166.5 in the middle and lower elevation respectively, while Pinus roxburghii with an IVI of 109.5 was dominant in higher elevation. Species richness and species diversity for tree layer ranged from 7 to 32 and 1.9 to 4.3, respectively. Eupatorium adenophorum in higher and Lantana camera in middle and lower elevation was the most dominant shrubs, respectively. Justicia simplex, Chrysopogon gryllus and Ageratum conyzoides was most dominant herbs in higher, middle and lower elevation, respectively. Shorea robusta and Pinus roxburghii showed regeneration along with their associated species in the respective forest site. The changes in diversity and composition of forests are required an urgent management options to ensure the conservation existing species in an integrated way of stakeholder’s participation.