Edilaine Duarte

SUCESSÃO EM FRAGMENTOS FLORESTAIS ALTOMONTANOS NO SUL DO BRASIL: UMA ABORDAGEM FLORÍSTICO-ESTRUTURAL E FILOGENÉTICA

We aimed to describe the floristic-structural organization, the richness and the phylogenetic structure of tree components in highland forest fragments in different successional stages, at Sao Joaquim National Park, in the municipality of Urubici, Santa Catarina state. Three fragments were selected, two in an advanced successional stage and one in an initial successional stage, being each one evaluated by 20 10 x 10 m sampling plots, allocated as 20 x 100 m transects. All trees with dbh ≥ 5 cm were identified and measured. The data were analyzed through rarefaction, multivariate ordination, indicator species analysis and phylogenetic structure metrics. There was no relationship between the richness and the successional stage, once the studied areas did not differ in relation to the number of species. The floristic-structural organization was influenced by the interaction between the successional stage and the environmental differences among areas. Phylogenetic clustering of species was observed in the initial successional stage area and random phylogenetic pattern was observed in advanced successional stage areas. The results indicated independent variation in richness in relation to successional phase and, that the forest succession influenced the floristic-structural composition and phylogenetic structure of the study areas.

REGENERAÇÃO NATURAL EM UMA FLORESTA COM ARAUCÁRIA: INFERÊNCIAS SOBRE O PROCESSO DE CONSTRUÇÃO DA COMUNIDADE DE ESPÉCIES ARBÓREAS

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.

Aspectos gerais e silviculturais de Cordia americana, Aspidosperma polyneuron, Toona ciliata e Khaya spp.

Brazil has a great diversity of forest species; however, the stands contain mostly species of Eucalyptus and Pinus. Faced with this, the present study is based on the analysis of the characteristics of native species with high potential and innovative character of timber species for cultivation. The Australian cedar (Toona ciliata) and African mahogany (Khaya spp.) are important species, mainly benefiting in reducing the exploitation of native forests remaining in the country. However, the species of (Cordia Americana) and (Aspidosperma polyneuron) show great potential yet to be explored, both in releasing commercial plantations and their proper use, that meets sustainability requirements.