Turning back from the brink: Detecting an impending regime shift in time to avert it
- 20 January 2009
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 106 (3), 826-831
- https://doi.org/10.1073/pnas.0811729106
Abstract
Ecological regime shifts are large, abrupt, long-lasting changes in ecosystems that often have considerable impacts on human economies and societies. Avoiding unintentional regime shifts is widely regarded as desirable, but prediction of ecological regime shifts is notoriously difficult. Recent research indicates that changes in ecological time series (e. g., increased variability and autocorrelation) could potentially serve as early warning indicators of impending shifts. A critical question, however, is whether such indicators provide sufficient warning to adapt management to avert regime shifts. We examine this question using a fisheries model, with regime shifts driven by angling (amenable to rapid reduction) or shoreline development (only gradual restoration is possible). The model represents key features of a broad class of ecological regime shifts. We find that if drivers can only be manipulated gradually management action is needed substantially before a regime shift to avert it; if drivers can be rapidly altered aversive action may be delayed until a shift is underway. Large increases in the indicators only occur once a regime shift is initiated, often too late for management to avert a shift. To improve usefulness in averting regime shifts, we suggest that research focus on defining critical indicator levels rather than detecting change in the indicators. Ideally, critical indicator levels should be related to switches in ecosystem attractors; we present a new spectral density ratio indicator to this end. Averting ecological regime shifts is also dependent on developing policy processes that enable society to respond more rapidly to information about impending regime shifts.Keywords
This publication has 40 references indexed in Scilit:
- Slowing down as an early warning signal for abrupt climate changeProceedings of the National Academy of Sciences of the United States of America, 2008
- Reinterpreting the State of Fisheries and their ManagementEcosystems, 2007
- Loss of Resilience, Crisis, and Institutional Change: Lessons from an Intensive Agricultural System in Southeastern AustraliaEcosystems, 2006
- Assessing the ecological risk from secondary salinity: A framework addressing questions of scale and threshold responsesAustral Ecology, 2005
- Dynamics of populations on the verge of extinctionOikos, 2005
- Regime Shifts in the Sahara and Sahel: Interactions between Ecological and Climatic Systems in Northern AfricaEcosystems, 2003
- The potential role of spectral properties in detecting thresholds in the Earth system: application to the thermohaline circulationOcean Dynamics, 2003
- Alternative attractors may boost uncertainty and sensitivity in ecological modelsEcological Modelling, 2003
- Global land cover characterization from satellite data: from research to operational implementation?Global Ecology and Biogeography, 1999
- Time Series Analysis: Univariate and Multivariate Methods.Journal of the American Statistical Association, 1991