Résumé
A declining rate of recovery following disturbance has been proposed as an
important early warning for impending tipping points in complex systems.
Despite extensive theoretical and laboratory studies, this ‘critical
slowing down’ remains largely untested in the complex settings of
real-world ecosystems. Here, we provide both observational and
experimental support of critical slowing down along natural stress
gradients in tidal marsh ecosystems. Time series of aerial images of
European marsh development reveal a consistent lengthening of recovery
time as inundation stress increases. We corroborate this finding with
transplantation experiments in European and North American tidal marshes.
In particular, our results emphasize the power of direct observational or
experimental measures of recovery over indirect statistical signatures,
such as spatial variance or autocorrelation. Our results indicate that the
phenomenon of critical slowing down can provide a powerful tool to probe
the resilience of natural ecosystems.