Runoff, soil loss, and water balance in a restored Karst area of the Brazilian Savanna

Abstract

Although data exist about the impact of karst soil restoration in some regions and climates, this information is lacking in the sub-humid Brazilian savannah. Runoff plots with distinct soil covers (bare soil, and ecologically restored areas with native species) were installed over a Lithic entisol on a karst slope of the Brazilian savanna (Cerrado), where runoff, erosion, and soil water balance were monitored during 3 hydrologic years. Mean runoff and erosion in the ecologically restored areas decreased from 546 mm yr−1 to 360 mm yr−1, and from 34 Mg ha-1yr−1 to 5 Mg ha-1yr−1, respectively. Soil loss tolerance was exceeded the bare plot of the Lithic entisol in all three hydrologic years. In the third year, erosion fell below soil loss tolerance in the restored plots, indicating that soil degradation could be effectively reduced with ecological restoration. The runoff and erosion data of the present study was fitted by an exponential relationship developed for non-karst soils of the Cerrado. Soil water balance was improved in the restored plots, increasing infiltration and evapotranspiration, and reducing runoff. The results fill an important information gap in tropical karst science, and could be utilized in similar settings.