ABSTRACT
Worldwide, drylands are under extreme threat due to predicted climate change and increasing land use pressure (Reynolds et al., 2007). This specifically holds for dry savanna rangelands, where livestock production is the dominant type of land use (Tietjen and Jeltsch, 2007). Already now, many savanna rangelands worldwide suffer from nonadapted land use in the form of overgrazing by livestock. Overgrazing, especially in combination with unfavorable rainfall conditions, is being held responsible either for a loss of vegetation cover and increasing risks of erosion or for an increase of less palatable woody vegetation at the cost of palatable herbaceous vegetationthe so-called phenomenon of bush encroachment (van de Koppel and Rietkerk, 2000; Weber and Jeltsch, 2000).
