Our objective in this paper was to characterize the floristics, structure and physiognomy of three different forests in distinct physiographic situations of the coastal plain. We sampled a forest over a non deep peat deposit (shallow peat forest), a forest over a deep peat deposit (deep peat forest) and a forest in a firm and dry soil (hillock forest), all these established in the Campina do Encantado State Park, Pariquera-Açu/SP, Brazil. We carried out a phytosociological survey trough blocks of contiguous plots of 10 × 10 m -- with a total area of 1.04 ha -- where all trees with DBH > or = 4.8 cm were sampled. We found a total number of 144 species, where 112 were in the hillock forest, 46 were in the shallow peat forest and five were in the deep peat forest. There was a small similarity within the three forests, with just a few species in common. This was specially remarkable when comparing the two peat forests with the hillock forest. Hillock forest presented a high Shannon diversity index (H' = 4.06 nat.ind.-1), that is typical of tropical forest environments. The shallow peat forest presented the expected Shannon's diversity index for this type of environment in coastal plains (H' = 2.98 nat.ind.-1). The deep peat forest presented a very low Shannon diversity index (H'= 0.82 nat.ind.-1) - the lowest ever registered for southern and south-eastern Brazil. The heterogeneity of the vegetation in continuous forested areas -- conditioned by coastal plain physiographic features -- shows that the protection of the greatest number of environmental situations is needed to promote in situ biodiversity conservation.
Atlantic Rain Forest; tropical peat forest; vegetational mosaic; phytosociology; coastal plains
