DENSE OMBROPHILOUS FOREST IN SANTA CATARINA - BRAZIL: CLUSTER ANALYSIS AND ORDENATION BASED ON SYSTEMATIC SAMPLING

This study aimed to characterize the remnants of Ombrophilous Dense Forest in Santa Catarina state. The dataset used in this study was provided by Project of Floristic and Forest Inventory of Santa Catarina, coming from 197 sample units that consist of basic clusters. The basic cluster was composed of four subunits of 20 x 50 m, in which all individuals with DBH >= 10 cm were measured. The forest structure was characterized through phytosociological parameters and indices. Based on structural data of the species, cluster analysis and ordination were performed in an attempt to identify groups of watersheds and altitude ranges. It was identified 577 species belonging to 226 genera and 83 families. The most representative families in number of species and individuals were Myrtaceae, Lauraceae and Fabaceae. Species of disturbed areas as Alchornea triplinervia, Caseria sylvestris and Miconia cinnamomifolia were dominant in the forest. Cluster analysis resulted in the identification of three vegetation types along the altitudinal gradient: Lowland Ombrophilous Dense Forest (< 30 m a.s.l.), Submontane (30 - 500 m) and Montane (> 500 m). Floristic and structural variations could be detected between the three vegetation types. In lowland communities, the presence of Anacardiaceae and Clusiaceae was more expressive and the average height of trees was higher. In montane environments, there was an increase in the number of individuals, basal area and diversity, as well as a greater representation of Cyatheaceae, Lauraceae and Rubiaceae. The occurrence of Arecaceae was remarkable in submontane forest. Spatial groups could not be defined based on structural data of watersheds.