Disturbance is no new feature in the Arctic environment. The factors that create the Arctic habitat include marked climatic oscillations, physical disturbance and fluctuations in herbivore populations. The combination of environmental stress and disturbance due to habitat instability and the possibility of periods of intense grazing impose a particularly testing blend of adverse conditions for plant survival. The physical nature of the terrain, with constant soil movement through cryoperturbation and solifluction contributes to the fragility of Arctic habitats. To this scenario must be added disturbance by man, in the quest for natural resources or merely as a result of tourism. The Arctic landscape is undoubtedly one that is frequently repaired by natural succession, but whether or not this built-in resilience is adequate to restore degraded ecosystems after human intervention is an unanswered problem that forms the subject matter of this volume.