What do these concept mean? Can we use them in quantitative ecology? Structural properties Dynamic properties Descriptive Conceptually precise Quantitative ecology Normative Conceptually vague trans-disciplinary
There is no unique way to define resilience Vague terminology promotes creative thinking Being precise ensure testability of concepts Clarify specific concept and the associated measures & metrics Make sure these are applicable to a given system/data/model
Holling 1973 I propose that the behavior of ecological systems could well be defined by two distinct properties: resilience and stability. Resilience determines the persistence of relationships within a system and is a measure of the ability of these systems to absorb changes of state variables, driving variables, and parameters, and still persist. In this definition resilience is the property of the system and persistence or probability of extinction is the result. Stability, on the other hand, is the ability of a system to return to an equilibrium state after a temporary disturbance… In this definition stability is the property of the system and the degree of fluctuation around specific states the result.
Westmann, 1978 Elasticity: rapidity of restoration of a stable state following disturbance. Pimm, 1984 Resilience: how fast the variables return towards their equilibrium following a perturbation. Resilience is not, therefore, defined for unstable systems.
Engineering vs. ecological resilience: the marble metaphor Ecological Resilience ~ probability of staying in the valley Engineering resilience ~ rate of return to the bottom of the valley Peterson et al., 1998
Walker et al., 2004 Resilience is the capacity of a system to absorb disturbance and reorganize while undergoing changes so as to still retain essentially the same function, structure, identity and feedbacks. Cumming et al., 2005 We equate resilience with the ability of a system to maintain its identity, where system identity is defined as a property of key components and relationships (networks) and their continuity through space and time. Levin and Lubchenko, 2008 the notion of resilience is sometimes interpreted in the general literature in the narrower sense of recovery from disturbance, and at other times in the broader sense of the maintenance of functioning in the face of disturbance. Within this article, we adopt the broader definition, and we do not distinguish it from robustness.
Derissen et al., 2011 Some authors explicitly define or implicitly understand the notions of resilience and sustainability such that they are essentially equivalent. Levin et al (1998) claim in general that resilience is the preferred way to think about sustainability in social as well as natural systems, thus also suggesting an equivalence of resilience and sustainability.