Is the future of oak (Quercus spp.) forests safe in the Western Himalayas?

摘要

The genus Quercus (oak) is a large group of hardwood trees with about 600 species worldwide1. In the Himalayan region, extensive oak forests (35 species) occur between 1500 and 3300 m elevations. Five species of evergreen oaks, viz. Quercus glauca (phaliyant/harinj), Quercus leucotrichophora (banj), Quercus floribunda (tilonj/moru), Quercus lanuginosa (rianj) and Quercus semecarpifolia (kharsu) grow naturally in the Western Himalayas and each species is replaced by the other to form the climax community along the increasing altitude. At 2000 m and less Q. leucotrichophora exhibits 80% dominance (based on relative basal area), between 2000 and 2200 m it may share dominance with Q. floribunda and above this it generally disappears. In small patches between 2100 and 2400 m, Q. floribunda may show clear-cut dominance but with further increase in elevation, it is replaced by Q. semecarpifolia, which may show more than 70–80% dominance above 2600 m asl. These species assume considerable conservation significance in the region as they provide numerous ecosystem services and serve as a lifeline for the local communities.