In the course of regularly grappling with resilience questions, many of which Rebecca Benner has posed, I have found three elements of ecosystem resilience that keep surfacing: stress resistance, recovery and adaptation. For coral reef resilience, we focus principally on the resistance and recovery elements in the face of thermal stress. We have yet to monitor and manage for adaptation. My answers to her questions will reflect that experience.
Why should we do resilience analyses — and do these need to do more than indicate where resilient places are? “Where” is important. It enables us to: (a) build resilient habitats into conservation planning as foundations for broader conservation planning; (b) help direct development along sustainable pathways by avoiding these resilient areas; and (c) focus management efforts on places with best potential for persistence.
Are “adaptive capacity” and “resilience” synonymous? Not fully. Resistance and recovery are central to the way we manage reefs, design MPA networks and deliver training. We monitor, measure and manage reefs to maintain status quo rather than to enhance acceptable levels of change — an arguably flawed approach in a rapidly changing world. However we define resilience, we should capture all three elements: resistance, recovery, adaptive capacity.
What do we do with resilience: build, enhance or protect it? We need to manage to restore, enhance and protect resilience. And we may well need to expand to proactive interventions that bolster the coastal protection functions of natural systems (as with oyster reefs) or change water chemistry to buffer the impacts of ocean acidification.
Should we take similar approaches in marine, terrestrial and freshwater systems? I’m comfortable advocating that we do need to enhance or build and protect resilience in all systems. In the marine world, we protect resilient areas because these provide sources of seed to repopulate the susceptible areas in times of stress. This approach surely would apply to all systems. These refugia form the core of our conservation investment, our blue chips. And Rebecca is correct: We need to build out from these or embed them into broader management frameworks, as indeed we are doing through our “reef to ridges” approach that links reef and watershed management.
Is resilience a site-specific topic and not useful as a generalized framework? Our coral reef work shows that site specificity provides the nuance and the generalized framework still remains useful. We need a larger toolbox of case studies of applications to help us adapt our approaches at different sites.
We do need to accept that resilience is a little-understood concept in which new knowledge regularly changes the way we think. This poses the question Rebecca did not ask: if there are so many unknowns, should we bother? I am not at all put off that different efforts to model climate change impacts and vulnerability yield sometimes very different results, that the indicators of resilience are constantly being modified, and that analysis of these indicators can yield different rankings depending on how they are combined. Each new attempt and each iteration of an old one yields more information to help us hone our efforts.
For now, a good approach would seem to be:
Capture the variability in resilience among habitats by including multiple replicates of all habitat types into conservation area networks and separating these widely apart to reduce the risk of any stress event taking out all protected examples of one habitat.
Choose larger areas for protection over smaller to capture a) the variability of resilience within habitats and, at the same time, b) any uncertainty and acclimation in stress response. By investing time and effort in large areas, we are more likely to capture all pieces of the different patterns that make up the mosaic of how ecosystems will respond at the local, management-scale level to such large stress events as heat stress, rainfall changes, storms and acidification.
Protect naturally resistant refugia.
Develop better field indicators for identifying resilience.
Rod Salm is the senior advisor for science and strategies in the Indo-Pacific Division of The Nature Conservancy.