This study aimed at evaluating the fitossociology of Mixed Rainy Forest, departing from the
grouping analysis. For that, six conglomerates were used, each one with 16 plots, where the arboreal and
shrub individuals with breast height circumference (CAP) equal or larger than 30 cm was identified and
measured. The species were classified in ecological groups and, beginning with the density data, a grouping
analysis was accomplished using the method TWINSPAN (Two-way Indicator Species Analysis). The
groupings were characterized in relation to their horizontal structure. In the area, 86 species were identified,
being 18 pioneers, 25 secondary initials, 16 secondary late, 14 climax and 13 were classified in more than
one group. Three groupings were identified (Groups 1, 2 and 3), where the species
Siphoneugena reitzii
,
Araucaria angustifolia
and
Sebastiania commersoniana
were stood out, respectively, in hillside
environment, open and humid forest. It was observed that the individuals' presence with smaller diameter
will guarantee the permanence of these species for a medium period. It is ended that interventions
silviculturais in this ecosystem consider the presence of different groupings, characterized by environment
and specific species.