Grazing effects on belowground C and N stocks along a network of cattle exclosures in temperate and subtropical grasslands of South America

The study evaluates changes promoted by livestock removal across temperate and subtropical grasslands for amounts and vertical distribution of organic carbon (C) and nitrogen (N) contents in different belowground pools; and for soil bulk density, as affected by trampling. Also evaluated was the association of these changes with climate and soil properties in general. Total soil organic matter (SOM) stocks were significantly higher in ungrazed than in grazed stands of upland soils, and lower in shallow and lowland soils. Surprisingly, differences were largely associated with changes in mineral associated organic matter (MAOM) rather than particulate organic matter (POM) pools