Structural analysis of the restinga forests associated with Pleistocene and Holocene marine deposits in the Itaguaré River Basin, Bertioga (SP)

Abstract

In the Brazilian coastal plains, the relationship between the Restinga phytophysiognomies and sedimentary deposits are still poorly understood. This paper presents the main structural aspects of tree components from two types of Restinga forests (Restinga low Forest - FbR, and Restinga high Forest - FaR), which cover three different generations of marine deposits outcropping in the coastal plain area of the Itaguaré River basin, Bertioga (SP), and also describes the spatial variations in the concentrations of some chemical elements in soil, associated with these forest remnants. The parcel method assumed that all individuals have DBH ≥ 10 cm. Density, basal area and tree height were measured. The results show that in FbR, the trees have the smallest diameters and heights, as well as little relationship between DBH and height. Considerable variations occur in the two types of FaR as a function of marine deposit age, soil evolution and chemical properties; so that the best developed forest covers the most ancient deposits with the most evolved and richest soils. The organic layer deposited on top of the soil is very important for balancing the dynamics of the cycling of nutrients available to plants. According to the environmental law CONAMA nº 07/1996, these phytophysiognomies are still well-preserved, since they are in advanced stage of regeneration in FbR, and are primary or native in FaR.