Pedochronology and development of peat bog in the environmental protection area pau-de-fruta - Diamantina, Brazil

• Published in: Revista Brasileira de Ciência do Solo 2010-12, Vol.34 (6), p.1965-1975
• Main Authors: Campos, José Ricardo da Rocha(USP Esalq Departamento de Ciência do Solo), Silva, Alexandre Christófaro(UFVJM Departamento de Engenharia Florestal), Vasconcellos, Leandro Lara(UFVJM Scientific Initiation student), Silva, Daniel Valladão(UFVJM Departamento de Agronomia), Romão, Rafael Vitor(UFVJM Scientific Initiation student), Silva, Enilson de Barros(UFVJM Departamento de Agronomia), Grazziotti, Paulo Henrique(UFVJM Departamento de Engenharia Florestal)
• Format: Article
• Language: English
• Subjects: atividade microbiológica; datações radiocarbônicas; humic substances; matéria orgânica do solo; microbial activity; Organosols; Organossolo; radiocarbon dating; soil organic matter; SOIL SCIENCE; substâncias húmicas; δ13C
• ISSN: 0100-0683; 1806-9657; 0100-0683
• DOI: 10.1590/S0100-06832010000600021

In the region of the Serra do Espinhaço Meridional, peat bog is formed in hydromorphic environments developed in sunken areas on the plain surfaces with vegetation adapted to hydromorphic conditions, favoring the accumulation and preservation of organic matter. This pedoenvironment is developed on the regionally predominant quartzite rocks. Peat bog in the Environmental Protection Area - APA Pau-de-Fruta, located in the watershed of Córrego das Pedras, Diamantina,Brazil, was mapped and three representative profiles were morphologically characterized and sampled for physical, chemical and microbiological analyses. The organic matter was fractionated into fulvic acid (FA), humic acids (HA) and humin (H). Two profiles were sampled to determine the radiocarbon age and δ13C. The structural organization of the three profiles is homogeneous. The first two layers consist of fibric, the two subsequent of hemic and the four deepest of sapric peat, showing that organic matter decomposition advances with depth and that the influence of mineral materials in deeper layers is greater. Physical properties were homogeneous in the profiles, but varied in the sampled layers. Chemical properties were similar in the layers, but the Ca content, sum of bases and base saturation differed between profiles. Contents of H predominated in the more soluble organic matter fractions and were accumulated at a higher rate in the surface and deeper layers, while HA levels were higher in the intermediate and FA in the deeper layers. Microbial activity did not vary among profiles and was highest in the surface layers, decreasing with depth. From the results of radiocarbon dating and isotope analysis, it was inferred that bog formation began about 20 thousand years ago and that the vegetation of the area had not changed significantly since then. Na região da Serra do Espinhaço Meridional, a formação de ambientes hidromórficos em áreas deprimidas de superfícies de aplainamento, aliada à ocorrência de uma vegetação adaptada à condição de hidromorfismo, favorece o acúmulo e a preservação de matéria orgânica, formando turfeiras. Esse pedoambiente desenvolve-se sobre rochas quartzíticas, predominantes na região. A turfeira da _rea de Proteção Ambiental - APA Pau-de-Fruta, localizada na microbacia do Córrego das Pedras, município de Diamantina - MG, foi mapeada e três perfis representativos foram caracterizados morfologicamente e amostrados para caracterização física, química e microbiológica.