Effect of altitude and climate in shaping the forest compositions of Singalila National Park in Khangchendzonga Landscape, Eastern Himalaya, India

Himalayas provide high altitudinal gradients and extreme slopes which may rapid changes in climatic zones over a small distance which reflects noticeable changes in the forest community structures. We identified and analyzed various aspects of forest community composition with the effect of climatic variables and altitudes in the Singalila National Park (SNP), Khangchendzonga Landscape in Eastern Himalayas (India). We encountered 2075 woody individuals of 70 species within a transect (2000 m-3636 m asl). The entire forest regime reflected a dominance of young trees and the species richness showed a negative correlation with the altitude. Climatic variables (actual evapotranspiration, potential evapotranspiration and moisture index) are the measures of available environmental energies which drive the final shape of forest community structure. Our study revealed that these forces showed a significant relationship with species richness and altitude of the forest which provides the present shape of forest community composition structure of the SNP.