ABSTRACT
In Mixed Rainy Forest, natural regeneration is not studied very well. In Rio Grande do Sul, due to anthropic actions, it is under different alteration conditions, in some cases, forming fragments. This study aimed to analyze the floristic of natural regeneration and to verify the occurrence of floristic groups in the area where no pronounced alterations were found. The area with 1606,69 ha was located at São Francisco de Paula National Forest (among 29° 23 ' and 29° 27 ' S; 50° 23' and 50° 25 ' W), displayed in 1.606,69 ha, in São Francisco de Paula municipal county, RS. In the study, 6 permanent growing stands of PELD (Long Duration Ecological Project) were selected, the vegetation was inventoried, using 10 parallel strips to each other and perpendicular to the direction of the topographical position, which presented 10 m of width and 100 m of length, subdivided into 10 units of 100 m², totalizing 1 ha, where were raffled 3 sample units for strip to identify and measure (height and circumference) the individuals with Cap higher or equal to 3 cm and smaller than 30 cm. The lianas, creepers and herbs also had their circumferences measured and identified up to the species level, when possible. The density data for species formed a matrix (180x70) used in the multivariate analysis. The presence of vegetation grouping in state of natural regeneration inside the forest was tested by TWINSPAN Method (Two-way indicator species analysis). The existence of three ecological groups (G-1, G-2 and G-3) was proved. G-1 was characterized by good water availability and for having intermediate environmental characteristics, for locating in the topographical position regarding the medium hillside. G-2 occurred in the base hillside of the forest, presenting strong influence of the hydric saturation and subjected to sporadic overflow; and, in G-3, in the topographical position of the hillside higher/plateau that consequently doesn't suffer influence of the elevation of hydric saturation. The indicative species of the groups were: Sebastiania brasiliensis Spreng. (G-1); Matayba elaeagnoides Radek., Myrceugenia myrcioides Cambess O. Berg , Myrceugenia oxysepala (Burret) D. Legrand et Kausel and Cinnamomum glaziovii (Mez) Kosterm.(G-2); and Zanthoxylum petiolare A. St.-Hil & Tul. (G-3).
Keyword s:
multivariate analysis; vegetation grouping; ecological groups