Quantifying aeolian soil loss after forest conversion in the Chaco ecoregion

Sperl, Daniel Vanacker, Veerle [UCL] Dunai, Tibor

The Chaco ecoregion (NW Argentina) is characterized by the highest forest loss rates worldwide, as a result of agricultural expansion at agro-industrial scale. The conversion of dry forests to agricultural plots enhances the soil erosion vulnerability by exposure of bare soil after deforestation. The unconsolidated loess-type sediments are particularly susceptible to wind erosion during the prolonged dry season. In this study, the role of land use and management on soil erosion will be analysed. All investigated plots are characterized by flat topography. For this reason it is very likely that observed soil losses will be largely due to wind erosion, since such low gradients are not amenable to efficient water erosion. We hypothesise that changes in land use have a high impact on the mobilization of sediments in the Chaco ecoregion. We posit that a transformation from forest into crop/rangelands, will lead to enhanced mobilization of sediments by wind, whereas the establishment of no-tillage farming in this region might slow translocation rates down to near natural levels.