The Quadrant Method was applied in dense forest on a sandstone mine in Serra Pará State. , All living or dead individuals with DBH 10 cm were sampled (one > individual per quadrant). In 104 points (or 416 individuals) sampled, 38 families, 85 genera and 110 species were registered. The families presenting the highest importance value index (VIF) were Sapotaceae (40,90), Leguminosae sensu latu (26,76) and Rutaceae (25,82). Erisma uncinatum Warm, was the species presenting the highest importance value index (15,86); as a group, dead trees presented the second highest index (14,07). The calculated density was 1 065 individuals/ha. The basal area was 28.9057m² for the 416 sampled individuals, or 74.0502m²/ha. The estimated density as well as the basal area per unit area (ha) were considered extremely high for the region. The structure of the vegetation was also analyzed: the mean diameter was 31,21 cm; the mean heigths of trunks and crowns were 12,4 m and 5,8 m respectively, giving a mean total of 18,2 m. The understory vegetation was also described qualitatively.
rainforest; point-centred quarter method; floristics; structure; phytossociology