Dry weight estimation of the aboveground components of Melaleuca quinquenervia trees in southern Florida

Abstract

Allometric equations were derived and dry weight distribution was determined for aboveground components (total wood, trunk, branch, leaf, seed capsule, seed) of Melaleuca quinquenervia trees in south Florida. Aboveground tree components of 42, 46, and 50 trees, harvested from dry, seasonally flooded, and permanently flooded habitats, respectively, were separated, sorted, sub-sampled, dried to constant weight at 70°C, and weighed. The effects of diameter at breast height (dbh) on dry weight of the aboveground components were significant. Predictive allometric equations were derived for each component using dbh and/or dbh 2×tht (total tree height) as predictors. Based on R 2 values the accuracy of the equations for biomass prediction are ranked as, total wood>trunk>branch>leaf>seed capsule>seed. Diameter at breast height alone was a good predictor of dry weight of the aboveground components of trees. When dbh was combined with total tree height, R 2 improved somewhat for all components except for seed capsules and seeds. Proportions of the dry weight of total wood and branch increased, but trunk and leaf decreased as dbh increased. Wood constituted the greatest proportion (83–96%) across the dbh range (0.1–38.6 cm) in all three habitats. Leaves and seed capsules represented a greater proportion of dry weight in permanently flooded habitats (leaves, 10–13%; seed capsules, 3–4%) than in both dry and seasonally flooded habitats (leaves, 4–12%, seed capsules, up to 2%). Overall leaf proportion decreased as dbh increased.