Estimating above-ground biomass in six mangrove tree species, north eastern Queensland

Mangrove trees of six species were sampled in order to derive allometric relationships for estimating leaf biomass, branch biomass, stem biomass and total above-ground biomass from measurements of the diameter of the stem at breast height (DBH). Rhizophora apiculata, Rhizophora stylosa, Bruguiera gymnorhiza, Bruguiera parviflora, Ceriops tagal var. australis and Xylocarpus granatum were sampled from the mangrove forests of Hinchinbrook Island, the Murray River and the Daintree River in north Queensland between 1985 and 1988.For each species, the diameters of stems of trees from a range of size-classes were measured. The trees were then felled and divided into leaves, branches, stem and above-ground roots. The fresh weight of each component was measured in the field and subsamples of each component were collected, weighed and taken to the laboratory for determination of dry weight. This research was undertaken to determine if allometric relationships existed between stem diameter at breast height (DBH) and above-ground biomass, which would enable reliable, non-destructive estimates of the biomass of mangrove trees. Reliable estimates of biomass combined with growth rates are required for estimates of primary productivity.