PARENT SESSION
Oral Session #45: Biogeography and Metapopulations.
Presiding: T. Miller
Tuesday, August 6. 1:00 PM to 4:45 PM. Grand Ballroom Central, Radisson.

A generalized framework of metapopulation dynamics.

Harding, Karin^*,1,2, McNamara, John³, ¹ Woods Hole Oceanographic Institution, Woods Hole, MA² Swedish Museum of Natural History, Stockholm, Sweden³ University of Bristol, Bristol, England

ABSTRACT- A new, generalized model of metapopulation dynamics can incorporate knowledge from epidemiology, genetics and population biology in a phenomenological way. The main types of metapopulation dynamics arising from some important biological processes are illustrated: the rescue effect, the Allee effect, and what we term the 'anti-rescue effect'. The anti-rescue effect captures instances where high migration rates are deleterious to population persistence, a phenomenon that is rarely considered in metapopulation conservation theory, but is well known from other fields (such as epidemiology and genetics). Management regimes that ignore a significant anti-rescue effect will be inadequate and may actually increase extinction risk. Despite its simplicity, the generalized model can exhibit complex behaviours such as multiple and unstable equilibria of patch occupancy. These phenomena were earlier thought to be consequential only of models including details about local dynamics (such as population size or patch quality). We show how complex structured metapopulation models can be translated into our generalised model; this correspondence facilitates the understanding of the dynamic behaviour of specific complex models. Simulation of complex models is necessary for explicit investigation of the importance of given local processes. The new, generalized model aims at providing a complementary tool for the understanding of metapopulation biology.

KEY WORDS: metapopulation, migration, rescue-effect, Allee-effect