Ecological variation among natural populations of Terminalia chebula Retz in Sirmour and Una districts, Himachal Pradesh

The present study was confined to two natural populations of Terminalia chebula Retz distributed in Sirmour and Una districts of Himachal Pradesh. In every natural population 5 quadrats of 30 x 30 m (900 sqm) size determined by species area curve method were randomly laid to study tree species. In each quadrat, a sub-quadrat of 5 x 5 m (25 sqm) size was selected for study of shrubs. Among trees T chebula was dominant tree species in Jamun Ki Sair and Ghanu with IVI value of 109.01 and 78.36 respectively. Among shrubs Murraya koengii was dominant species in both the populations having IVI value of 127.74 in Jamun ki Sair and 76.10 in Ghanu. Population-wise species diversity in trees ranged from 2.8 to 2.16, species dominance from 0.75 to 0.80, species richness from 2.67 to 3.12 and equitability from 0.77 to 0.82. Species diversity in shrubs ranged from 1.31 to 2.01, species dominance from 0.80 to 0.84, species richness from 0.72 to 1.84 and equitability from 0.92 to 0.94.