AN INSIGHT INTO WOODY SPECIES IN SUB-TEMPERATE FOREST ECOSYSTEM IN DARJEELING HIMALAYA, INDIA: AN EVALUATION OF SPECIES COMPOSITION AND DIVERSITY

Abstract

The present study aims to determine woody species composition and diversity in sub-temperate forests of Darjeeling Himalaya. In order to collect data, sample plots sized 20 m × 20 m were deployed and the diameter at breast height (DBH) of all woody species was measured. A total number of 609 individuals belonging to 30 families under 41 genera and 51 species were encountered. The most frequently occurring species were Cryptomeria japonica, Lithocarpus fenestratus, L. pachyphyllus, Quercus glauca, Eriobotrya dubia, Syzygium kurzii, Alnus nepalensis, Exbucklandia populnea and Magnolia lanuginosa. The values of Shannon and Menhinick indices were 3.870 and 2.067 respectively. Similarly, dominance was estimated as 0.022 while evenness showed a value of 0.984. Furthermore, the total basal area estimated was 186.632 m² ha^-1 and the importance value index ranged from 2.013 to 16.855. Moreover, dominance-diversity (d-d) curve showed a log-normal species distribution. The regeneration status of dominant woody saplings revealed that 40% showed good regeneration, 20% had poor regeneration while 40% lacked regeneration. These findings provide an enhanced understanding of woody stands diversity and composition in the study area.