Morphology, Physical and Chemical Characteristics of Mangrove Soil under Riverine and Marine Influence: A Case Study on Subaé River Basin, Bahia, Brazil

Abstract

The preservation of mangrove ecosystem requires knowledge on soil Morphology, Physical and Chemical Characteristics, for understanding the requirements for their sus-tainability and preservation. Seven pedons of mangrove soil, five under fluvial and two under marine influence, located in the Subaé River basin were described and classified. Samples of horizons were collected for physical and chemical analyses, including Pb and Cd. The moist soils were suboxidic, with Eh below 350 mV. The pH of the pedons under fluvial influence ranged from moderately acid to alkaline, and pedons under marine influence was around 7.0. Mangrove soils under fluvial influence were characterized with the highest Pb and Cd concentrations in the pedons, which could be perhaps due to it closeness to the mining company Plumbum, while the lowest Pb concentrations was registered in the pedon furthest from the factory. Because the pedons had at least one metal above the reference level they were considered potentially toxic. The soils were classified as Gleissolos Tiomórficos Órticos (sálicos) sódico neofluvissólico, according to the Brazilian Soil Classification System and as Thiomorphic orthic Gleysol (salic) sodi cluvissol (potentially toxic, very poorly drained) according with FAO. The pedon under marine influence was classified in the same subgroup, but the metal concentrations met the acceptable standard.