Murundus fields: bioturbation and evolution of aluminous lateritic soils and vegetation in the Cerrado

Abstract

Fields of murundus are circular or elliptical micro topographies presents in the hillsides and in the headwaters of drainage, which remain temporarily or permanently flooded by rainwater and the groundwater level, and the presence of internal microrelief. Are widely distributed in tropical savanna formations as well as in sedimentary plateau of "Triângulo Mineiro", in the Cerrado biome. Are important areas by provide many environmental services such as: to aggregate endemic flora and fauna, store and regulate water flow in the basin, filter and retain sediments and contaminants, have intense biological activity, store carbon, and others. The occurrence of murundu's fields in the sedimentary plateau of Cerrado "mineiro" is tied to bioturbation process - integrating physical and biochemical processes - and seems to be responsible for the evolution of soil and landscape in this biome. Therefore, this study aims to understand the process of bioturbation of the soil and its relation to Cerrado vegetation and degradation of ferruginous cuirasses and formation of aluminous clays in murundu's field area of the Cerrado "mineiro", helping to emphasize the importance of these areas conservation, which are being converted into agricultural areas. It is expected to find at field a close relationship between bioturbation by termites and geochemical processes in soil that provide favorable conditions for the iron loss in ferruginous cuirass and the formation of aluminous clays. Through macromorphological and micromorphological analyzes done at field and at laboratory, we intend to characterize the role of termites on ground and the effects of such processes in the murundus's fields landscape, specifically in the Cerrado vegetation, between the cities of Uberaba and Uberlândia. Statistical analyzes (PERMANOVA) will be done to test the difference in number of species between the mounds and their surroundings, to see if there is a significant pattern to the mounds, as well as also analyze the micromorphological variables identified in soil samples.