Structure and dynamics in remnants of Araucaria Forest in Southern Brazilian plateau

Abstract

The present work aimed the characterization of the structure and dynamics of a forest patch belonging
to the Ombrophylous Mixed Forest (FOM). Data from 10 permanent plots (25 x 100 m) representing the forest
subtype "predominance of Araucaria", located at the Forest Reserve Embrapa-Epagri, in Caçador, State of Santa Catarina, were analyzed. Each tree whose girth at breast height (GBH) was equal or larger than 60 cm was
measured and identified. Measurements were taken annually from 2004 to 2007, thus allowing the dynamics to be evaluated for this period. The structure was analyzed by estimating phytossociological parameters and indexes and by characterizing the diameter distribution. Forty-one species, gathered into 24 families, were observed. Araucaria angustifolia, Ocotea porosa, Cupania vernalis, Capsicodendron dinisii e Matayba elaeagnoides showed the highest importance value. The distribution of diameter classes was represented by an inverse "J" curve. The Shannon diversity index (H´) was 2.54 for species and 2.22 for families. Most of species presented an uniform distribution, in accordance with McGuinnes index. Jaccard index values practically do not exceed 50 %.
The analysis of the dynamics revealed low diameter increments and mortality rates higher than recruitment ones.