Wood specific gravity and aboveground biomass of Bombacopsis quinata plantations in Costa Rica

Abstract

Measurements of dry matter production in forest plantations are needed to assess the limits to potential production. There are almost no studies about wood specific gravity, crown composition, and total biomass distribution of Bombacopsis quinata plantations. Wood specific gravity and aboveground biomass distribution were studied in B. quinata plantations growing in two different climatic zones of Costa Rica. Allometric models were developed for individual trees, and total biomass production per hectare was obtained by applying these models to sample plots. Wood specific gravity was found to be higher at the base of the tree (0.330 g cm −3) than at the base of the living crown (0.280 g cm −3); a tendency to increase with diameter at breast height (DBH) could also be observed at both stem sections. Foliage, branch, and stem biomass were highly correlated with DBH ( r>0.68, n=17). Branch and foliage dry biomass varied between 25 and 45% of the total tree dry biomass. The stem dry weight represented 55–75% of the total tree dry weight. From easy-measuring variables (DBH and height ( H)), difficult-measuring or time-consuming variables (e.g., foliage biomass) can be estimated. Models developed in this study estimate foliage dry biomass from DBH and H from branch dry biomass and from crown diameter. Estimations of foliage dry biomass from branch dry biomass could be useful for studies carried out in the dry season when B. quinata trees do not have foliage. In the regression analyses, variable transformations (log 10) improved the results when compared to original values of non-transformed variables.