Resilience
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Definition
Resilience may be defined as the capacity of a system to absorb disturbance and reorganize while undergoing change, so as to still retain essentially the same function, structure, identity and feedbacks. In ecological systems, resilience is a measure of how much disturbance an ecosystem can handle without shifting into a qualitatively different state. It is the capacity of a system to both withstand shocks and surprises and to rebuild itself if damaged. There are several examples of ecological systems that have undergone dramatic changes in structure and function as a response to external stresses, such as the shift of a freshwater system from a state of clear water, benthic vegetation, oligotrophic macrophytes and abundant fish to a eutrophic state characterized by turbid water, blue-green algae and where fish is absent. Another documented example is the case of marine systems changing from a state dominated by coral reefs, kelp forests and rich biodiversity to a state dominated by algae and urchins and depleted fish stocks. Many ecologists no longer focus on the ―carrying capacity‖ of given territories (with their assumed smooth Verhulst‘s curves indicating maximum populations of species that one territory could carry) but rather focus on the resilience of ecosystems.
Social resilience is the ability of human communities to withstand and recover from stresses, such as environmental change or social, economic or political upheaval. Resilience in societies and their life-supporting ecosystems is crucial in maintaining options for future human development. Resilience, for social-ecological systems, has three defining elements: (1) the magnitude of shock that the system can absorb and remain within a given state; (2) the degree to which the system is capable of self-organization; and (3) the degree to which the system expresses capacity for learning and adaptation. More resilient socio-ecological systems are able to absorb larger shocks without changing in fundamental ways. When massive transformation is inevitable, resilient systems contain the components needed for renewal and reorganization (Folke, et al., 2002).
In summary, resilience is the potential of a system to remain in a particular configuration and to maintain its feedbacks and functions, and involves the ability of the system to reorganize following disturbance-driven change.
Resilience assessment and management
Management can destroy or build resilience. Managing for resilience enhances the likelihood of sustaining development in a changing world where surprise is likely. The focus is on maintaining the capacity of the system to cope with whatever the future brings, without the system changing in undesirable ways.
The two aims of resilience management are: (1) to prevent the system from moving to undesired system configurations in the face of external stresses and disturbance (this can be achieved either by increasing resistance or by allowing a greater array of ―safe‖ resource use options) and (2) to enable the system to renew and reorganize itself following a massive change. This adaptive capacity, i.e., the capacity of a system to adapt and shape change, resides in aspects of memory, creativity, innovation, flexibility, and diversity of ecological components and human capabilities. Diversity is a key element for resilience in social-ecological systems. When the management of a resource is shared by diverse stakeholders (e.g., local resource users, research scientists, community members with traditional knowledge, government representatives), decision-making is better informed and more options exist for testing policies. Active adaptive management whereby management actions are designed as experiments encourages learning and novelty, thus increasing resilience in social-ecological systems.
Resilience assessment and management involves the following main steps:
- Resilience of what? The first step of a resilience assessment involves defining the system of interest and specifying issue(s) of concern. This is accomplished by describing the key attributes of the system, based strongly in stakeholder inputs;
- Resilience to what? This involves indentifying the main disturbances and processes that may influence the system, i.e. studying external disturbances and the development processes (policy drivers and stakeholder actions) to which the desirable configurations are expected to be resilient. Visioning and scenarios can be a useful tool in this stage;
- Resilience analysis. This step consists of exploring the interactions of the first two items to identify possible driving variables and processes that govern the dynamics of the system, looking especially for threshold effects and other non-linearities. Modeling can be used at this stage to develop further understanding of the dynamics of the system.
- Resilience management. The final step involves a stakeholder evaluation of the whole process and the implications of the emerging understanding for policy and management actions. This does not mean that the process is aimed at finding the ‗right‘ policies that keep the system in some pre-defined optimal path, but in defining a set of rules that enhance the system‘s ability to reorganize and move within some configuration of acceptable states, without knowing or caring which particular path the system might follow.
The Resilience Alliance has developed a set of workbooks to support resilience assessment directed for practitioners and scientists that can be downloaded from http://www.resalliance.org/.
References
- Folke, C., S. Carpenter, T. Elmqvist, L. Gunderson, CS Holling and B. Walker, 2002. Resilience and Sustainable Development: Building Adaptive Capacity in a World of Transformations, Ambio, Vol. 31 No. 5, August 2002, 437-440.
- Holling, C. S. 1973. Resilience and stability of ecological systems. Annual Rev Ecol Systems 4:1-23.
- Alliance, 2007. Assessing and managing resilience in social-ecological systems: A practitioners workbook. Version 1.0, June 2007.
- Resilience Alliance, 2007. Assessing and managing resilience in social-ecological systems: A workbook for scientists. Version 1.0, June 2007.
- Walker, B., C. S. Holling, S. R. Carpenter, and A. Kinzig. 2004. Resilience, adaptability and transformability in social–ecological systems. Ecology and Society 9(2): 5. [online] URL: http://www.ecologyandsociety.org/vol9/iss2/art5 .
