Diversity of Trees in the Darjeeling Foothill Region of Eastern Himalaya

Abstract

Phytosociological investigation using 20 x 20 m quadrats has been made on seven major forest types of Darjiling foothill region within an altitudinal range of 135 m to 1200 m leading to the record of 215 species of trees, 11 species of liana and three species of palms. Analysis of data revealed that the East Himalayan Sal forest showed highest species diversity but have moderate species richness and concentration of dominance. High species diversity and species richness were recorded from Semi Evergreen Mixed forest, Wet Mixed Deciduous Forest & Lower Bhabar Sal Forest with correspondingly low concentration of dominance. Bamboo brake had the lowest species diversity with high concentration of dominance. Computation of similarity index showed a poor relation between different forest types and reflected the developing nature of vegetation. Also, these forests have a high regeneration status with a good species composition. It has also been predicted that the anthropogenic interferences may cause the abrupt change in the structure of these vegetation types.