anatomia do lenho e dendrocronologia de lianas da família ...

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ABSTRACT
The lianas represent a considerable part of the richness and abundance in tropical forests and
they play basic role in many ecological processes. To better understand its role, it is necessary
to know some aspects of its biology, as the anatomy, the growth and the age of these
organisms. In the present study it is described and analysed the wood anatomy of eight lianas
species of the Leguminosae family, from the Parque Nacional do Itatiaia, located in the
South-eastern region of Brazil, inserted in Atlantic Rain Forest biome. Details of anatomy and
formation periodicity of the growth rings were verified. The species show characteristics
waited for lianas, as: wide vessel, with two categories of diameter; bigger parenchyma axial
ratio in comparison to fibres; and cambial variants. The wood anatomy of the studied species
is very similar for sharing the same habit and belonging to the same family. Despite the
similarities all studied species could be differentiated. The presence of distinct growth rings
was observed in the four species that did not presented cambial variants. The features that
delimit the layers of growth in these species are: semi-ring porosity, marginal parenchyma,
fibrous zone and radially flattened latewood cells. In these species was detected that the
growth layers were annual. The observed maximum age of these lianas was 27 years and the
radial growth rate averaged was 2,3 mm per year. Through the analysis of the time series, it
was observed that great similarities occur between rays of the same individual, however small
similarity between individuals and species. The climatological analysis of the time series
showed that few individuals presented significant correlation with precipitation, temperature
and incident sunlight. By means of the accumulated radial increment, a strong relation agediameter
was observed in lianas, however the deviation of an average accumulated increment
for the species increases together with the age.
Key-words: wood anatomy, lianas, Leguminosae, growth rings, dendrochronology,
secondary growth, age.