PEAT BOGS OF THE SERRA DO ESPINHACO MERIDIONAL - MINAS GERAIS, BRAZIL. I - CHARACTERIZATION AND CLASSIFICATION

Peat bogs are a special environment for studies related with the dynamics of organic matter, landscape evolution and climatic changes and with local, regional and global cycles of atmospheric pollution. Peat bogs contribute to the global C sequestration, act as water reservoirs and are the habitat of an endemic biodiversity. The Serra do Espinhaco Meridional (Minas Gerais State, Brazil) - SdEM - a terrestrial biosphere reservation area, contains a considerably large area with different types of peat bogs, which were described in three profiles at 1,250, 1,800 and 1,350 m above sea level and classified, respectively, as Organosol Haplic sapric terric (P1), Organosol Haplic fibric typical (P2) and Organosol Haplic Hemic typical (P4), in agreement with the Brazilian System of Soil Classification. The three profiles were characterized morphologically and the samples were chemically, physically and microbiologically analyzed. It was found that the location, altitude and drainage influenced the morphologic, physical, chemical, and biological properties of the peat bogs in SdEM. The decomposition state of organic matter is more advanced when the drainage in the peat bogs is better. The amount of heavy metals is related with the quantity and granulometric composition of the mineral fraction and location of the peat bogs. The highest mean levels of Ti, Zr, Pb were detected in profile P1, highest mean levels of Mn, Zn and Cu in P2, and the highest mean Fe content in P4. The intensity of microbiological activity in the peat bogs P2 and P4 was related with the drainage and heavy-metal content of its layers.