Plant Community Composition and Structure of Chenab Valley in a Part of Nanda Devi Biosphere Reserve

Abstract

The present paper deals with the vegetation communities and their diversity patterns in Chenab valley, the buffer zone of Nanda Devi Biosphere Reserve (NDBR) in Chamoli District of Uttarakhand, India. A total of 42 sites were selected randomly based on the landform heterogeneity of the area. Eight forest communities with overlap among vegetation types and also various plant associations were noticed through Principal Component Analysis (PCA) following PAST program and two shrub communities identified separately were, Berberis and bamboo. The range of density in various forest communities was from 203-545 trees ha-1 and total basal area from 17.5-71.7 m2 ha-1. The range of species richness of tree layer, shrub layer and herb layer was from 2-14, 1-10 and 4-14 and diversity from 0.693-2.304, 0.514-2.052 and 1.202-2.583, respectively. The distribution pattern of trees, shrubs and herbs shows that the species were evenly distributed in most of the sites and the ß-diversity of the present study area is 7.4. Rhododendron and Taxus, the undercanopy species facilitated the regeneration of Chimnobambusa falcata, while the conversion of lower girth class individuals to higher girth class individuals is steady and progressive. Though, evergreen and deciduous species had good population of seedlings and saplings, but the conversion to next girth class was very poor due to the high anthropogenic pressure. The present study reveals that the forest vegetation in Chenab valley is better than that of other parts of Nanda Devi Biosphere Reserve, for which conservation strategies have been discussed in the paper.