TREE STRUCTURE, REGENERATION AND WOODY BIOMASS REMOVAL IN A SUBTROPICAL FOREST OF MAMLAY WATERSHED IN THE SIKKIM HIMALAYA

This paper reports on the tree structure, tree dimension relationships and woody biomass production and removal of a sub-tropical natural fo rest in the Mamlay watershed of the Sikkim Himalaya. The forest provid es fuel, fodder and timber to four villages. Only 11 tree species were found growing in the tree stratum despite the high diversity in the s tand (32 tree species). The forest shows good regeneration potential w ith 5474 seedlings/ha and 1776 saplings/ha, but the population structu re revealed a marked paucity of trees of higher diameter classes due t o removal of trees of lower diameters. Standing wood biomass of 362 Mg /ha is mainly shared by 4 dominating species in the stand. The boles a re removed mainly for timber and fuel purposes and about 22 Mg/ha wood biomass was removed in between 1987-1991. Net Primary productivity of woody biomass of the forest is recorded to be 18 Mg/ha/year. 3.85 Mg/ ha of annual woody biomass production was removed in the form of tree boles apart from lopping of branches.