Patterns in Distribution, Population Density and Uses of Medicinal Plants along the Altitudinal Gradient in Dhauladhar Mountain Range of Indian Himalayas

We studied the patterns in distribution, population density and uses of medicinal plant species in Dhauladhar mountain range of Himachal Pradesh in Indian Himalayas. The study area was stratified into three zones on the basis of forest types and altitudes. In each zone, quadrats were laid down for sampling of plant species, and the local people were interviewed for gathering information on medicinal uses of plants. A total of 184 plant species were encountered in the sampling plots, of which 86% had medicinal uses. Among woody plant species, the use of bark was highest, whereas in herbaceous species the use of leaf and ischolar_main was highest for treatment of over 32 groups of diseases. In terms of density, Pinus roxburghii was the most dominant tree species in subtropical forests, which declined in temperate regions and was absent in subalpine forests. Rhododendron arboreum was the most dominant tree species in temperate region whereas in subalpine forests it was replaced by Abies pindrow, in terms of density. Berberis asiatica and Vitex negundo were the most dominant shrubs in subtropical forests besides Lantana camera, whereas Berberis lycium dominated the temperate and Juniperus indica dominated the subalpine forests. The heavy infestation of Lantana camera in sub-tropical forests has degraded the habitats of native medicinal plant species. Spearman’s correlation indicates positive correlation between local uses and density of respective medicinal plant species (P < 0.05). The results are further discussed in light of medicinal plants conservation in this part of the Indian Himalayas.