Document: BRI-3-51-24

When does migration matter in managing multiple populations?

HUDGENS, B.*

Duke University, Durham, NC 27708, USA ¹

Abstract:
Because management strategies for species with multiple populations depend on the degree to which population densities are affected by migration between populations vs local conditions there is a pressing need in conservation biology for well developed theory about when migration is expected to affect population dynamics. Previous studies of metapopulations of the aphid, Aphis lugentis suggest that the strength of predator prey interactions, local population growth rates and the number of suitable habitat patches within a metapopulation play important roles in determining the effect of migration on population dynamics. Using a simulation model of aphid metapopulation dynamics parameterized from field observations and experiments I tested how variation in the strength of predator-prey interactions, population growth rates and number of suitable habitat patches changed the effect of migration on population dynamics. I found that the importance of migration decreased when predator-prey interactions were very strong, increased when population growth rates were very low or very high, and decreased when their were fewer patches of suitable habitat in a metapopulation.

Keywords: metapopulation dynamics, aphids, conservation theory

This abstract is being presented at: 11:00 AM in session:
Oral Session #4: Herbivore Responses to Plants.