Caracterização ambiental, classificação e mapeamento dos solos da Ilha da Trindade, Atlântico Sul

• Autor(a) principal: Sá, Mariana Médice Firme
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5468
• topic: Solos ornitogênicos; Ilhas oceânicas; Solos; Ornithogenic soils; Oceanic islands; Soils; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

Trindade is a small volcanic island located in the southern Atlantic Ocean, 1140 km to the east coast of Vitória (ES), and together with the Martin Vaz archipelago, represents the easternmost point of Brazil. The only detailed study about the soils of Trindade was carried out by Clement et al., (2009), limited to a topossequence not covering the whole of the island, and excluded areas of ornithogenic influence. To date, little is known about the mineralogy, ecological relations and the genesis of soils on this remote island. This study aimed to promote the morphological, physical, chemical and mineralogical characterization of soils of Trindade island as well as the classification and mapping of soils and environmental characterization of the island. We described the landscape and soils, and collected samples from 22 soil profiles. Based on the Brazilian system of soil classification (SiBCS), the soils on the island of Trindade belong to three orders: Cambisols, Histosols and Neossols. In some soils were found difficulties in keying out within SiBCS, due to the absence of appropriate concepts, or because they had atypical features compared with continental soils. Most soils are young and stony, have high activity clay and large account of the primary clay mineral and basic cations. High CEC and eutrophic character, are typical of soils derived from basic rocks and/or dry climates. To a lesser extent, the dystrophic soils predominate in the higher parts of the island, associated with alkaline rocks. The occurrence of ornithogenic soil, associated or not with current nesting grounds, was confirmed, supporting the hypothesis of a former widespread bird influence, much greater than the current observed nesting would suggest. Some of these soils have marked peculiarities in relation to other ornithogenic soil, described in Fernando Noronha, st. Peter and st. Paul and Abrolhos. The effect of guano deposited by birds in Trindade seems to be more dispersed, especially in the lower coastal areas. Were found ornithogenic character in all three orders on the island, which were classified according to the degree of soil development and the degree of influence to pedogenesis. Many soils have a high proportion of amorphous minerals and andic properties, determined by X-ray, NaF pH, P-rem, and morphology, strongly suggesting an overall an “andic” character for Trindade soils.