PHYTOSOCIOLOGY OF WOODY VEGETATION UNDER DIFFERENT MANAGEMENT REGIMES IN GARHWAL HIMALAYA

Abstract

The present paper deals with the species composition, distribution pattern, diversity, concentration of dominance, community coefficient, beta diversity and equitability under four management regimes at the end of a study period of two years, i.e. in a forest grazing land located at Pauri (Garhwal): burnt protected (BP), burnt grazed (BG), unburnt protected (UP) and unburnt grazed (UG). On the burnt sites, tree, sapling and seedling strata were dominated by Pinus roxburghii, except in the BG site where the seedling stratum was co-dominated by Quercus leucotrichophora. In the shrub stratum, Berberis asiatica (BP) and Rhus parviflora (BG) dominated. On the UP and UG sites all the three strata were dominated by Cupressus torulosa, and within the shrubs Berberis asiatica was dominant. On the majority of the sites, most of the trees, saplings, seedlings and shrubs were widely distributed; however, only the UG site showed regular distribution in the sapling stratum. The diversity index for the tree stratum was higher on the burnt sites than the unburnt sites. The sapling stratum followed the opposite trend to the tree stratum. The diversity index for the seedling stratum ranged from 1.141 in the UG site to 1.876 in the BG site. The results of the study indicate that phytosociological changes of the woody vegetation are brought about by grazing and burning in terms of species composition, frequency, density and distribution. The shrub stratum recorded maximum index on BP (2.291) and minimum on UP (1.811). The values of dominance of concentration in general, followed an opposite trend to that of the diversity index for each stratum on all the study sites. The maximum similarity in the tree, sapling and shrub strata was recorded between the UP and UG sites. Beta diversity and equitability did not show any proper trend in all the sites in the different strata.