The objective of this study was to survey the flora in an area of 178,000 square meters at 29&º10'38''S and 51&º27'16''W, in Linha Palmeiro, in São Pedro, a district of Bento Gonçalves, Rio Grande do Sul, Brazil where the Botanical Garden of Bento Gonçalves is situated, an area with a transition zone that encompasses three distinct vegetation types: Mixed Ombrofilus Forest, Deciduous Forest and remnants of the Atlantic rainforest. The site is an in situ conservation area in the Botanical Garden of Bento Gonçalves. The sampling method used was a randomly distributed plot. Ten 50 x 50 m plots were evaluated. Samples of individuals with CBH (circumference at breast height) greater than or equal to 30 cm were taken from each plot. It was sampled 1,947 individuals living in 35 families, and 109 dead trees still standing. The most represented families in terms of number of individuals and species were Sapindaceae, Anacardiaceae, Myrtaceae, Oleaceae and Lauraceae. The species with the highest values of importance were Matayba elaeagnoides Radlk., Araucaria angustifolia (Bertol.) Kuntze, Lithraea brasiliensis Marchand, W. Ligustrum licidum T. Aiton and Sebastiania serrata (Klotzsch) Müll.Arg. The Shannon's diversity index was 3.18 nats/individuals and the Pielou equability (J') was 0.71 nats/indididual, high values when compared with other studies. The number of identified species showed an intermediate level of plant diversity, which was characterized by the association of different forest contingents with the predominance of those widely distributed in the area.
Deciduous Forest; Mixed Ombrofilus Forest; Phytogeography; Phytosociology
