QLS Seminar Series - Eric Pedersen

How do we define a patch? Deriving subpopulation structure from movement models using random-walk-based distance metrics

Eric Pedersen, Concordia University
Tuesday October 31, 12-1pm
Zoom Link: https://mcgill.zoom.us/j/86855481591
In Person: 550 Sherbrooke, Room 189

Abstract: The metapopulation framework is a cornerstone tool for modelling spatially structured populations. A metapopulation is defined as a set of subpopulations living in well-mixed patches, connected by inter-patch movement. However, there is currently no clear single definition of what constitutes a “patch” of habitat in fragmented and heterogeneous landscape. In this talk, I argue that we should define patches based on synchronization of population dynamics driven by local interactions between individuals. Further, when interaction is driven by individual patterns of movement and movement follows a Markov random walk, I show that it is possible to derive a measure of lifetime encounter probabilities between individuals inhabiting the landscape. This can be used to define a consistent metric for clustering locations on a landscape based on patterns of encounter probability. I demonstrate an eigenvector- based approach to approximating this metric for large complex landscapes, and show how this approach works for clustering simulated landscapes and spatially structured marine habitat of Northern Shrimp in northern Atlantic waters in Canada.