Tree Regeneration and Vegetation Structure in High Altitudes of Uttarakhand Himalaya, India.

The present paper is unique because of the use of modern statistical techniques to assess the species composition, distribution, and regeneration pattern at high altitude Himalayas. Threats to the forest community were also assessed at different survey sites. Stratified random sampling was carried out at 13 high altitude sites of Uttarakhand, from east to west at altitudinal range from 2500m to 4000m a.s.l., irrespective of protected areas. The tree species density was found maximum at Saukherk (665.5±192.3) followed by Mulakherk (586.2+367.7). A total of 16 regenerating tree species were recorded from 13 surveyed sites. The densities of regeneration tree species were low at all the surveyed sites especially towards the glacier; however, saplings were recorded maximum at Hitoli (5176.2±3690.4). PCA was performed to understand the patterns of relationship among various surveyed sites at the landscape level. The tree cover, density, diversity, and richness play a powerful role in discriminating the sites at PC I while the second PC is a gradient of grass and disturbances. The high altitude Himalayas have the anthropoegenic pressure due to tree cutting, lopping, cattle grazing etc. The mean tree cutting, lopping, cattle dung, grazing, and impact of the fire were assessed at different surveyed sites and threat scores were calculated. The Saukherk, Dungiadong are the least threatened sites while the Liwari, Mulakherk and Hitoli are the most threatened sites. [ABSTRACT FROM AUTHOR]