Meta-stable Vegetation Cover and Erosion Cycles

Erosion-deposition cycles are observed to parallel climate and land-use changes, but can they arise under constant exogenous factors? Results from a numerical geomorphic study suggest 'yes'. Vegetation dynamics (growth and death) were incorporated into a landscape evolution model by coupling erosion to vegetation density via the additional cohesion imparted by roots. The nature of the vegetation dynamics provided for a meta-stable vegetation density, which led to periodic, aperiodic, or absent oscillations in longterm vegetation cover and erosion rates, depending on the coupling strength. If such a signal is observable in nature, it would have implications on the identification of equilibrium systems and potentially paleoclimate estimates based on pollen counts.