Foliage biomass sapwood (area and volume) relationships of Tectona grandisLF and Gmelina arborea Roxb.: silvicultural implications

We developed foliage biomass to sapwood (area and volume) relationships for Tectona grandis L.E and Gmelina arborea Roxb. growing in the Guanacaste pr ovince of Costa Rica. Strong linear relationships confirmed the applicabili ty of Shinozaki's pipe model theory to both of these fast-growing, tropical species. The linear models include data from 80 (40 per species) dominant, codominant, and suppressed trees that had been growing in un-, late and ea rly thinned plantations and fence-row plantings. Results are applicable acr oss a wide range of foliage biomass values. The relationships between folia ge biomass and sapwood area and volume of the previous year's growth ring w ere also analyzed and were found to be highly significant for T. grandis. F indings confirm that silvicultural regimes of these species must allow indi vidual trees to augment foliage biomass from an early age if sustained rapi d diameter growth is desired. (C) 1999 Elsevier Science B.V. All rights res erved.