Sistemas Complejos

Title: Local return time to equilibrium as a proxy for large-scale ecological resilience, some evidence from an individual-based model
Speaker: Dr. Egbert van Ness, Universidad de Wageningen, Holanda
Date: Viernes 26 de octubre Hora: 16:00
Place: Salón de seminarios del Instituto de Física
Abstract: Ecological resilience has been defined by Holling (1973) as the maximum disturbance a system can absorb without shifting to another attractor. Though this stability measure is highly relevant for ecosystem management, it is notoriously hard to determine in practice. Up till now the dominant approach has been the use of models to estimate the basin of attraction of the stable states of the system, but the results of such approach are rather uncertain. Recently, we have shown that the recovery rate after disturbances (also known as the "engineering resilience") becomes very long close to a catastrophic regime shift in simple ODE models, a phenomenon called “critical slowing down”. Here we analyze a spatial-explicit individual-based model of aquatic vegetation (CHARISMA) and a simpler spatially explicit model that can have alternative stable states. We demonstrate that the repair rate of a local disturbance can be related to the ecological resilience, and discuss why this seems likely to be a generic property. We suggest that monitoring the rate of repair of local disturbances could be a practical way to assess the ecological resilience of systems that may be prone to large scale state shifts.