The specific gravity (MEb) is one of the main parameters of wood properties. Considering that, this study aimed to evaluate the longitudinal variation of the basic density of the wood of Cordia americana (Linnaeus) Gottshling & J.E. Mill and Alchornea triplinervia (Sprengel) Müller Argoviensis. The trees were selected in a fragment of subtropical semideciduals forest (local name Floresta Estacional Decidual), in Iraí-RS, Brazil that, after logging, were measured and scaled by the method of Smalian. To examine the wood density, discs were collected with about two centimeters at positions base, 1.3 m (DBH), 25, 50, 75 and 100% of the height along de stem. Two wedges being withdrawn symmetrical and opposite, which was obtained green volume, wood saturated and dry weight in an oven at 103C (±2°C). Alchornea triplinervia (S.) showed homogeneous wood density in the longitudinal direction of the stem, and Cordia americana (L.) had decreased wood density towards base-top.
Guajuvira; Tanheiro; native species; stem quality
