Growth of Araucaria angustifolia in the Embrapa/Epagri forest reserve, Caçador, SC, Brazil

Abstract

Araucaria Forest is one of most threatened phyto-physiognomies in the Atlantic Forest domain,
presenting great ecological-economical importance. Nevertheless, there are still lacks of knowledge concerning growth and dynamic of important species, as Araucaria angustifolia. The objective of this work was to recover  the past growth of Araucaria angustifolia, native from Caçador, SC, Brazil, by measuring growth rings and to estimate the average periodic diametric increment. The growth rings were counted and measured, using a stereoscope microscope, in increment cores of 0.5 cm collected from 32 adult trees. The measurements were done with LINTAB measuring table, with 0.01 mm of precision. The samples sizes were irregular, varying from 4.2 to 20.2 cm long. The trees presented average diameter breast height (DBH) of 76.3 cm, varying from 10.7 to 141.3 cm. The periodic diameter increment from the last 10 years was 0.4 cm, varying from 0.11 to 1.15 cm. It was observed differences among trees, but there was a tendency of reduction of growth rhythm in larger trees, being more
evident in trees with more than 110 cm of DBH.