Sucessão florestal secundária no município de São Pedro de Alcântara,litoral de Santa Catarina: estrutura e diversidade

The forest succession process in the coast of Santa Catarina State, Brazil, is characterized by easily defined stages. In this paper the were characterized these stages regarding species richness and diversity index (Shannon-Weaver index – SWI), density groups, DBH distribution, and basal area. The study was carried out in the municipality of Sao Pedro de Alcântara, located 50 km from the state capital, Florianopolis, where the forest cover is typical of the Brazilian Mata Atlantica. Six 10x10 m plots were measured in each of the succession stages called Myrsinietum , Miconietum , and Secondary Forest. All individuals of tree and shrub species 1 m or taller were measured. The Myrsinietum stage, with a strong dominance by Myrsine coriacea , was characterized by a small species diversity (SWI = 2.09 nats), with many individuals of each species in the smaller DBH classes (<10 cm), resulting in a low basal area (6.99 m 2 /ha), despite the high density of plants. In the Miconietum stage, dominated by Miconia cinnamomifolia , there is a high number of individuals in the classes up to 20 cm in DBH, with maximum of 35 cm, resulting in a basal area of 33.67 m 2 /ha. In this stage, there was a high number of species with high diversity (SWI = 3.55 nats), most of them occurring sparsely. In the Secondary Forest stage, there is a high number of trees in the DBH classes up to 15 cm, but some individuals reached more than 52 cm, resulting in a basal area of 39.11 m 2 /ha. In this stage, 50% of the species occur very sparsely, with a diversity index (H) of 3.48 nats. According to the results of this study it is not possible to conform the succession stages of Myrsinietum, Miconietum e Mata Secundaria with the regeneration stages defined by the Resolution no04/1994 of CONAMA. The characteristics of each succession stage showed the large dissimilarity between the Myrsinietum and the other stages from the point of view of structure as well as ecological aspects. These dissimilarities can subsidize strategies of use and conservation of local forest resources.