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Woody plant encroachment is one of the major threats to mesic grasslands. Dynamics of encroachers is mainly controlled by fire. The absence of fire for a year can be considered a disturbance, because it creates a temporal window where a cohort of woody encroachers can establish and thereby reduce grass production. Grazing pressure removes grass biomass and decreases the probability of fire ignition and spreading. We developed a spatially implicit minimal model of encroacher dynamics to investigate the role of grazing pressure and woody plant encroachment rate on the resilience and stability of a mesic grassland. A specificity of the model is the inclusion of a feedback loop between the density of encroachers and fire probability, so that fire is an emergent property of the system. Model results show that a mesic grassland is stable and resilient when characterized by a low encroachment rate and a low grazing pressure. If the grazing pressure is high and the encroachment rate is low, the grassland suffers from long term encroachment at low densities. If the encroachment rate is high with a low grazing pressure the grassland can be colonized very quickly in the rare years without fire. Based on these considerations, we give directions for management.