ABOVE-GROUND BIOMASS ESTIMATION OF A SECONDARY FOREST IN SARAWAK

Abstract

An above-ground biomass study of trees, shrubs, ferns, grasses and lianas in a 10- to 14-y-old secondary forest at Semengok, Kuching was carried out in 1981 as part of a study of nutrient cycling in shifting cultivation land. This was done by destructive sampling in a 20 x 10 m plot of representative vegetation sited on a midslope of 15 degrees. Ninety-four per cent of the above-ground oven-dry weight biomass totalling 32.0 t ha^-1 were made up of trees and shrubs of diameters 5cm and above. The tree and shrub stratum averaged 8.1 m in height and 6.2 cm diameter at breast height and was dominated by Trichospermum kurzii, Macaranga spp., Dilienia suffruticosa and Vitex pubescens. The undergrowth was dominated by a sedge, Cyperus cyperinus, while the liana component was mainly Embelia effusa. The aboveground biomass of trees and shrubs was 58.3% stem wood, 12.9% stem bark, 15.3% branches, 6.5% twigs and 6.9% leaves. Regressions of shoot total height and shoot component dry weights on dbh and or dbh²h were significant.