Ecological trends in the wood anatomy of some Brazilian species. 1. Growth rings and vessels

Some ecological trends based on wood were established in woody florulas of several regions in Brazil. Growth rings and qualitative vessel features were analysed in trees belonging to the 22 most representative families of the Brazilian flora, including 133 genera, 491 species and 686 specimens. Some ecological trends were statistically proven by Pearson's Standardised Residues. The presence of growth rings was associated with seasonal environments. Vessels tended to show special arrangement patterns at higher latitudes and in environments affected by thermal seasonality. Vessels in multiples were more common in environments that were seasonal for temperature and humidity. Although not statistically significant, there is a trend for multiple perforation plates and helical thickenings to be most common in higher latitudes and colder environments. Overall, the results for Brazilian species are compatible with trends established by other authors for other floras and/or taxa.