ESTIMATION OF ABOVE-GROUND BIOMASS OF TREES AND SHRUBS IN A EUCALYPTUS-POPULNEA F MUELL WOODLAND BY REGRESSION OF MASS ON TRUNK DIAMETER AND PLANT HEIGHT

An estimate of the above-ground biomass of leaf and wood in the shrubs and trees of Eucalyptus populnea woodland near Cobar, N.S.W., was made, by regression of leaf and wood weight on height or trunk diameter of the most common species. A new double regression technique was used for E. populnea to avoid destructively sampling whole trees. The mass of branches was regressed on primary branch diameter and these equations were used to estimate the total mass of crowns of trees. The estimated crown mass was then regressed on trunk diameters. Regression equations for estimation of mass of wood and leaf are provided for Geijera parvifora, Cassia nemophila, Dodonaea viscosa, Eremophila mitchellii, E. sturtii, E. bowmanii, Myoporum deserti and young Acacia aneura. The error of the estimates varied between 3 and 18% for different species. Log transformation of the data usually improved the correlation coefficients obtained but sometimes increased the standard error of the estimate. Estimates based on canopy measurements were rarely more accurate than those from height or trunk diameter. The overall estimate of biomass was 3.4 t of leaf and 51.4 t of wood per ha with a standard error of < 15%. © 1979 CSIRO. All rights reserved.