The objective of this work was to characterize and classify Cambisols of the Fernando de Noronha Archipelago to test and improve the Brazilian System of Soil Classificaton (SiBCS). For this ecological complex of touristic importance, information on soil characteristics and landscape distribution is essential to plan the land use and government actions focusing on sustainable land use. Based on a Detailed Soil Survey of the Fernando de Noronha Archipelago, six representative Cambisol profiles were morphologically characterized and samples were collected for physical, chemical and mineralogical analyses. The studied Cambisols were classified in subgroups according to the SiBCS, 2nd edition. At this point, the development of our study resulted in the proposal of a large new group, "Ta Eutroferric". In the Archipelago the soil properties are strongly influenced by the parent material of volcanic origin, the dry tropical climate with oceanic influence and the relief. Typic Ta Eutroferric Haplic Cambisols were found in the most preserved parts of the Central Plateau on the main island, and are the best soils for agricultural and geotechnical purposes. The leptic Ta Eutroferric Haplic Cambisols, frequently observed in steep slope topography and associated with Litic Neosols and rock outcrops, require special protection due to the high erosion susceptibility. On the other hand, the vertic Sodic Haplic Cambisols, which occur in the slightly lower lands of the Central Plateau, have serious limitations of drainage and swelling clays. Chemically, the levels of extractable soil P were high to extremely high, with irregular distribution, both across soil profiles and horizons, suggesting the influence of different sources of this nutrient.
Brazilian oceanic islands; soil taxonomy; Cambisols
