ECOLOGICAL TRENDS IN THE WOOD ANATOMY OF SOME BRAZILIAN SPECIES. 2. AXIAL PARENCHYMA, RAYS AND FIBRES

Abstract

Some ecological trends in wood anatomy were established in florulas from several regions in Brazil. Characteristics of the axial and radial parenchyma and fibres were analyzed in trees belonging to 22 families of the Brazilian flora, including 133 genera, 491 species and 686 specimens. Some ecological trends were statistically supported by Pearson’s Standardised Residues. At lower latitudes, the axial parenchyma was predominantly paratracheal and more abundant; the rays were thinner, and the fibre walls thicker. At higher latitudes, the parenchyma was predominantly apotracheal and not so abundant, the rays were wider and the fibre walls thinner. Fibre wall thickness was related to humidity. Thinner walls were found in more humid environments, thicker walls were associated with drier environments. No trends for ray composition were identified. Overall, the results for Brazilian species are compatible with trends established by other authors.