The influence of soil factors on the different vegetation formations of the Dunas Park, Salvador, Bahia, Brazil

This article was conducted in a restinga ecosystem on quaternary sandy deposits of Parque das Dunas, Salvador, Bahia, Brazil; located north of Salvador, this area comprises a landscape formed by different edaphic gradients with varied vegetation formations. An edaphic characterization of the sections of these remnants was carried out to understand the influence of edaphic factors on the distribution of the plant composition of this environment. For this purpose, a transect was delimited perpendicular to the coastline. In this transect, 08 plots of 25x25m were implanted, 100m apart. In the Centre of each plot, a 1m wide and 60 cm deep trench was opened, where soil samples were collected to determine edaphic and granulometric parameters. These samples in each plot followed the distribution of the vegetation formations of this environment. It was found that the different water regimes and topography of the area influence the soil factors, which interferes with the distribution and heterogeneity of the vegetation. The highest levels of fine, very fine and medium sand fractions and calcium and phosphorus were found in the highest portions. These areas, with better drainage, have a higher plant density. There is a lower vegetation density with open sandbanks in lower areas, lower levels of fine, very fine and medium sand fractions, and lower nutrient retention. In these environments, some areas are partially flooded with adapted species. It was also found that most of the plots had a very acidic pH with the presence of exchangeable Al, which could indicate high nutrient unavailability. Thus, the sandbanks' soil conditions influence the vegetation's development, inducing the plant species to develop adaptive mechanisms to maintain their biological organization.