Babassu (Attalea speciosa C.Martius, Arecaceae) is a palm with extraordinary socioeconomic and ecologic importance in large areas of tropical Brazil, especially in frequently burned and degraded landscapes. Nevertheless, surprisingly little is known about this keystone species. This paper investigates the allometry of babassu, in order to improve understanding on palm architecture and to provide researchers with an efficient tool for aboveground biomass estimation of juvenile and adult palms. Juvenile leaf biomass can be accurately predicted with the easily measurable minimum diameter of rachis at 30 cm extension. Adult palm biomass can be estimated based on woody stem height, a variable fairly easily measurable on-field. Leaf biomass of adult palms was highly variable, averaged 31.7% of aboveground biomass and can be estimated only indirectly through the relationships between wood:leaf-ratio and total aboveground biomass. Carbon contents varied little in the babassu palm, without size- or growth-stage related differences, suggesting the general applicability of values (42.5% C for stems, 39.8% C for leaves). As a consequence of the limited secondary diameter growth inherent to palms, stem diameter of adult palms is unrelated to palm height and biomass. Stem tapering decreases with increasing palm height. This is partially compensated by increasing wood density in near cylindrical stems. Nevertheless, maximum babassu palm height of about 30 meters appears to be dictated by mechanical stability constraints. All allometric relationships of babassu described in this study are not affected by vegetation stand age, indicating the general applicability of these relationships.
Attalea speciosa; biomass estimation; carbon; plant architecture; wood density
