Floristics diversity composition along an altitudinal gradient in Himalayan chir pine forest of the western Himalayas

In the present study, we examined the species composition of Himalayan Chir Pine forest (Pinus roxburghii Sargent) at different altitudes between 1000-1600m asl, considering three altitudinal gradients viz., A1(Lower altitude: 1000-1200m); A2(Middle altitude: 1200-1400m); A3(Higher altitude: 1400-1600m) in the Western Himalayas. In this study, a total of 50 species were recorded, of which 9 were trees, 15 shrubs, 26 herbs. Herb plant richness (in number) showed a diminishing trend with altitude whereas shrub species remain same for low and mid altitudes with slight drop in high altitudes and the tree species richness remain constant for all the altitudes. Many types of environmental changes (altitudes, slopes, aspect, temperature, precipitation etc.) influence the processes that can both augment or erode diversity. The study suggests that species distribution, presence of the particular species (species composition) and number of species present (species richness) are largely regulated by altitudes and other climatic + topographic factors.