RADIAL VARIATION OF TRACHEID FEATURES, SPECIFIC GRAVITY AND GROWTH RINGS IN Araucaria angustifolia (Bertol.) Kuntze PLANTED IN CUNHA-SP

Abstract

We investigated wood features along growth rings of Araucaria angustifolia trees planted between November and December of 1980 in Parque Estadual da Serra do Mar in Cunha, State of São Paulo, Brazil. Our goal was to determine radial variation of the tracheid features and specific gravity. For these analyses, we employed the usual methodologies for determining the tracheid dimensions by maceration. Based on the relationship between weight/volume of samples and growth rings, specific gravity was determined after discs were polished. Following the Typical Radial Pattern – (TRP), we observed a significant increase in length, diameter and wall thickness of tracheids toward the bark. Positive relationships were observed between all tracheid features and specific gravity, showing that the increase in length and, especially, wall thickness contributed to the increase in specific gravity toward the bark.