A study was conducted to understand the plant diversity along an altitudinal gradient with elevations varying from 2750 to 5000m above msl in Lippa – Asrang valley falling in cold desert area of Pooh sub division of district Kinnaur, Himachal Pradesh during 2007. The number of tree species at 2750-3200m and 3200-3650m elevations were 10 and 8 with the dominance of Cedrus deodara and Pinus wallichian respectively. The number of shrub species were 19, 17, 7 and 3 in the elevations of 2750-3200m, 3200-3650m, 3650-4100m and 4100-4550m respectively. Juniperus communis taking shape of the dominant shrub at 2750-3200 m, 3200-3650 m and 3650-4100m elevations. Rhododendron anthopogon was the dominant shrub at 4100-4550m elevation range. The number of herb species were 76, 73, 46, 39 and 33 at 2750-3200m, 3200-3650m, 3650-4100m, 4100-4550m and 4550-5000m elevational ranges respectively. On the basis of importance value index (IVI), Artemisia brevifolia, Heracleum candicans, Thymus linearis, Bergenia stracheyi and Bistorta affinis were the dominant herbs dotting different elevational ranges and distribution pattern of plant species was mostly contiguous in all the altitudes. Index of diversity for herb species in different elevational ranges was 3.89, 3.82, 3.47, 3.21 and 2.95. Out of 78 medicinal plant species as recorded from the area, 20 species fall in the category of threatened plants. The better conservation of natural resources can be well achieved through promotion of community based conservation stressing in-situ conservation through the establishment of nature reserves and ex-situ conservation through tissue culture, developing cultivation technologies and nurseries of medicinal plants and conducting regular trainings on the procedure of medicinal plants collection, processing amongst the end users/ the local people, traders and real stake holders.
Effects of boundary constraints and climatic factors on plant diversity along an altitudinal gradient