Contributions of Forest Biomass and Organic Matter to Above- and BelowGround Carbon contents at Ayer Hitam Forest Reserve, Malaysia

Three 0.1 ha forest plots in Peninsular Malaysia were studied for aboveground carbon from biomass and belowground carbon in the soil. Soil samples were collected from four layers for determination of colour, texture, bulk density and carbon with the carbon–nitrogen–sulphur analyser. Herbaceous plants were extracted from subplots and processed for determination of biomass and carbon of aerial parts and roots. Stem diameters of trees were obtained. Total carbon content in the soil decreased with depth from 1.86 (0–29 cm) to 0.81% (90– 120 cm), whereas bulk density in the same layers increased from 1.15 to 1.51 g cm-3. The 60–120 cm layers contained 42% of the total carbon. The amounts of carbon found up to 120 cm depth, excluding large roots, superficial litter and coarse debris were 154, 174 and 208 t ha-1 in the three plots studied. Plots were very heterogeneous with regard to herbaceous vegetation, these contributing less than 0.01 t ha-1 carbon—main roots making up 30% and aerial parts being 3% richer. The three plots had 87, 195 and 205 t ha-1 of carbon from biomass of trees above the ground. Annual increments of litter, debris and root carbon were estimated.