PRELIMINARY BIOMASS EQUATIONS FOR EIGHT SPECIES OF FAST-GROWING TROPICAL TREES

Abstract

Biomass allometric equations and tested predictions were produced from previously published equations by harvest of 2-y-old tree
plantations in Hawaii. Equations of the form B = aDBH^b, where B is total above ground biomass, were fitted to harvest data of Acacia mangium, A. mearnsii, Casuarina equisetifolia, Eucalyptus grandis, E. robusta, E. saligna, E. urophylla, and Leucaena leucocephala. Equations
derived at Mountain View, Hawaii, were compared with independent data from Kilohana, Kauai. Regression of In B versus In DBH for 16 to 20 trees per species had r2 ranging from 0.89 to 0.98. Height did not contribute significantly to biomass regression in seven of the eight species. Where estimates of mean total dry weight within 20% accuracy are sufficient, the published equations may be used. Equations from harvest of a relatively small number (e.g. 20) of trees can produce substantially better estimates for a given site, but these equations may not extrapolate to other sites any better than published equations.