Livestock management promotes bush encroachment in savanna systems by altering plant–herbivore feedback

Savannas are characterized by the coexistence of two contrasting plant life-forms: woody and herbaceous vegetation. During last decades, there has been a global trend an increase in cover spread shrubs trees into areas that were previously dominated grasses. This process, termed bush encroachment, is associated with severe losses ecosystem functions typically difficult to reverse. It assumed be example critical transition between alternative stable states. Overgrazing due unsustainable rangeland management identified as one main causes this transition, it can trigger several self-reinforcing feedback loops. However, dynamic role grazing within such loops received less attention. We used set coupled differential equations describe competition grasses, well biomass consumption via browsing. Grazers receive certain level care from farmers, so grazer densities emerge dynamically combined effect vegetation abundance farmer support. quantified all self-dampening at play analyzed their relative importance shaping system (in-)stability. Bistability, presence grass shrub state, emerges for intermediate levels support positive arises grasses herbivory. furthermore demonstrate disturbances, drought events, abrupt transitions state becomes more susceptible disturbances increasing Our results thus highlight potential interaction networks combinations loop analysis improving our understanding general, encroachment particular.