Forest–savanna ecosystems: Dynamics, bistability, and resilience Empirical evidence suggests that across large regions of the tropics, closed-canopy forests and savannas can exist as alternative stable states—a phenomenon with major implications under ongoing climate change. We analyse a spatially extended version of the Staver–Levin model of forest–savanna dynamics, illustrating how spatial processes sustain bistability and generate a rich variety of additional behaviours. Spatial organisation strongly influences ecosystem resilience, and we demonstrate that this holds in our models by examining pattern-forming instabilities. To study resilience in spatially structured systems, we introduce a new approach for quantifying transitions between patterned states in randomly forced systems, drawing on the landscape–flux formalism from statistical physics. We conclude with a discussion of open modelling and applied challenges, including environmental heterogeneity, timescale separation, and data integration. This article was published on 2026-03-02
