Resistance, Resilience and Restoration

Abstract

SummaryDisturbances (pulse, press and ramp) constitute a major force influencing, even determining, the structure and functions of ecological components – populations, communities and ecosystems. The capacity to weather a disturbance without loss is defined as resistance, whereas resilience is the capacity to recover from a disturbance after incurring losses, which may be considerable. This article seeks to resolve differences in the ecological definition of resistance and of resilience and to examine the importance of resilience as applied to ecological restoration. In restoration, interventions are designed and implemented with the aim of strengthening the resilience, that is, the capacity to recover, of degraded systems. In response to restorative measures, degraded systems may have both resistance and negative resilience to remain in the degraded state. The key aim of restoration is to overcome the resistance and negative resilience of the degraded state by strengthening positive resilience, the capacity to recover to the intact undegraded state. Restoration may be hindered by a lack of knowledge of acting disturbances (both past and present), of the previous intact condition and of appropriate interventions to implement. Resilience to a disturbance is determined after the disturbance has ceased. Thus, for current ongoing press and ramp disturbances, resilience can be hard to determine.