NATURAL REGENERATION IN AN AURACARIA FOREST: INFERENCES ABOUT THE PROCESS OF TREE SPECIES COMMUNITY ASSEMBLAGE/REGENERACAO NATURAL EM UMA FLORESTA COM ARAUCARIA: INFERENCIAS SOBRE O PROCESSO DE CONSTRUCAO DA COMUNIDADE DE ESPECIES ARBOREAS

This study aimed to describe the floristic composition of the regenerative component and to relate it with the adult component of an Araucaria Forest fragment, in South Brazil, in order to infer about the process of tree species community assemblage. To do so, five 10 x 20 m transection were allocated, in a forest fragment located at municipality of Lages, SC state. Each transect was made up by five plots, 20 m from each other, subdivided in different sizes, according to the sampled size class. The adult and regenerative components were compared each other for floristic-structural organization (Permutational Multivariate Analysis of Variance and Indicator Species Analysis), richness (rarefaction), population, individual spatial distribution (Standardized Morisita Index), and pattern of species coexistence or segregation in the studied plots (C-score Index). The results demonstrated significant differences between adults and regenerating components in relation to floristic-structural similarity and to richness. The adult component presented a greater proportion of populations with a random spatial distribution; and a smaller coexistence of species in plots than the regenerative component. We infer that the tree community assemblage is under influence of different ecological process, which intensity is ontogenetic dependent. Keywords: Mixed Ombrophyllous Forest; floristic-structural organization; spatial distribution patterns; species coexistence. O presente estudo teve como objetivo caracterizar a composicao floristica do componente regenerante e relaciona-la ao componente arboreo adulto de um fragmento de Floresta Ombrofila Mista no Sul do Brasil, com o proposito de inferir sobre os processos de construcao da comunidade de especies arboreas na area. Para isto, foram utilizadas cinco transeccoes de 100 x 20 m, alocadas em um fragmento florestal localizado no municipio de Lages-SC. Cada transeccao foi formada por cinco parcelas, distantes 20 m entre si, subdividas em tamanhos distintos de acordo com a classe de tamanho da planta avaliada. Os componentes regenerante e adulto foram comparados quanto a organizacao floristico-estrutural (Analise de Variancia Multivariada Permutacional e Analise de Especies Indicadoras), riqueza (rarefacao), distribuicao espacial dos individuos das populacoes (Indice de Morisita Padronizado) e padroes de coexistencia e segregacao das especies nas parcelas (Indice de C-score). Os resultados demonstraram diferencas significativas e