Ecological resilience for ecologists

Benjamin Planque, Grégoire Certain, Raul Primicerio, Kathrine Michalsen, Lis Lindal Jørgensen, Michaela

Aschan, Padmini Dalpadado, Mette Skern-Mauritzen, Edda Johannesen, Susanne Kortsch, Magnus Wiedmann

what does resilience mean?

BarEcoRe:Resilience of the Barents Sea ecosystem

to climate and fishing

the ability to absorb disturbance and maintain structure and function

The multiple facets of resilience

What do these concept mean?Can we use them in quantitative ecology?

Structural properties

Dynamic properties

DescriptiveConceptually preciseQuantitative ecology

NormativeConceptually vaguetrans-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.