Allometric equations for estimating the above-ground biomass of cacao stands in the eastern amazon basin. In: Agrotrópica v. 6 p. 65-72, 1994.

Abstract

Allometric relationships are described for estimating cacao tree (Theobroma cacao L.) leaf, branch, bole, and total above-ground dry biomass from measurements of bole diameter and height, primary branch diameter, and maximum canopy height. Eight cacao trees in a 16 - 17-year-old plantation in Tomé-Açu, Pará, Brazil, in the eastern Amazon Basin, were measured and destructively sampled for component wet and dry weight determinations. Stepwise regression was used on log-transformed measures to develop equations of best fit; the best overall predictor of total and component dry biomass was the sum of the bole and branch diameters, (D,.). Correlation coefficients for allometric regressions ofbiomass variables on DI were generally above 0.90, with over 98% of the variation in branch and total biomass accounted for by variation in DI. The simply and rapidly measured sum of the stem and primary branch diameters should be useful for providing accurate estimates of above-ground dry cacao tree biomass in plantations in Amazonia, and perhaps elsewhere where management practices result in cacao trees with similar growth forms to those studied in Tomé-Açu.