Understanding the phenomena of carbon exchange between soils, waters and atmosphere is critical to the management and conservation of agrarian and natural ecosystems. The objective of this study was to determine the organic carbon stocks and their fractions, and the soil fertility under different forest management practices, agricultural and pastoral, on the campus of Florestal, Federal University of Viçosa, aiming to propose indicators for the assessment of soil management and conservation. Organic carbon stocks and fractions were determined and chemical analysis was performed for soil samples collected at depths of 0 to 20 and 20 to 40 cm under native forest remnants (Forest), farmlands under center pivot irrigation (Pivot) and areas of cultivation of Corymbia citriodora (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) (Eucalyptus), Joannesia princeps Vell. (Cutieira) and Brachiaria decumbens Stapf (Pasture). The results indicated that the organic carbon stokes and stability increased with the soil fertility. The forest systems, mainly the native forest remnants together with management systems integrating forests with livestock, compared with continuous cropping or monoculture pasture had larger, more stables and less soluble carbon stocks, with more aromatic and hydrophobic forms (greater HA/FA ratio), indicating lower leaching potential of carbon to the adjacent aquatic system
management and soil conservation; soil chemistry; soil organic matter; environmental sciences
