Resilience

by

Craig Allen, Ahjond S. Garmestani, David Angeler

• LAST REVIEWED: 25 February 2016
• LAST MODIFIED: 25 February 2016
• DOI: 10.1093/obo/9780199363445-0048

Introduction

Resilience is an important framework for understanding and managing complex systems of people and nature that are subject to abrupt and nonlinear change. The idea of ecological resilience was slow to gain acceptance in the scientific community, taking thirty years to become widely accepted (Gunderson 2000, cited under Original Definition). Currently, the concept is commonplace in academics, management, and policy. Although the idea has quantitative roots in the ecological sciences and was proposed as a measurable quality of ecosystems, the broad use of resilience led to an expansion of definitions and applications. Holling’s original definition, presented in 1973 (Holling 1973, cited under Original Definition), was simply the amount of disturbance that a system can withstand before it shifts into an alternative stability domain. Ecological resilience, therefore, emphasizes that the dynamics of complex systems are nonlinear, meaning that these systems can transition, often abruptly, between dynamic states with substantially different structures, functions, and processes. The transition of ecological systems from one state to another frequently has important repercussions for humans. Recent definitions are more normative and qualitative, especially in the social sciences, and a competing definition, that of engineering resilience, is still often used. Resilience is an emergent phenomenon of complex systems, which means it cannot be deduced from the behavior of the individual parts of a system. Scientists understand complex systems to be self-organizing (i.e., positive reinforcements exist, often between biota and abiotic processes, such as fire), to be hierarchically structured, and to possess uncertainty, nonlinear dynamics, and emergent phenomena. Complex systems are self-organizing because there is no central entity responsible for directing processes and functions, and there is reinforcement between structure and process. This article focuses on ecological resilience but also describes engineering resilience and other uses of the term.

Original Definition

Original resilience concepts (as described by Holling 1973 and clarified in Gunderson 2000) emphasize that complex systems, including ecosystems, are hierarchically structured, meaning that patterns and processes are compartmentalized by distinct scales of space and time. Resilience, therefore, captures the richness of behavior in complex systems better than concepts such as stability, which do not explicitly emphasize scaling. When a system is forced beyond the boundaries of a domain of attraction, a qualitatively different pattern of structure and behavior may emerge, maintained by a different set of structures or processes (a new “regime”). It is often quite evident when the resilience of a system has been exceeded and the system qualitatively changed, e.g., when a lake flips from a clear to turbid state. A state change (i.e., a shift between system states) can be abrupt and dramatic or slow and subtle, depending on the structures and functions in the system that influence the magnitude of the feedback between the agents and the system itself and the scale of observation.

• Gunderson, L. H. 2000. Ecological resilience—in theory and application. Annual Review of Ecology and Systematics 31:425–439.

  DOI: 10.1146/annurev.ecolsys.31.1.425

  This paper reviews research on resilience and introduces the concept of adaptive capacity.

• Holling, C. S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics 4:1–23.

  DOI: 10.1146/annurev.es.04.110173.000245

  The seminal article introducing the concept of ecological resilience.