Michael Catchen

Student Speaker | Étudiant.e
Humans are rapidly reshaping our planet, leaving Earth’s habitats smaller and patchier. Understanding and predicting the impacts of landscape change on ecological processes has been a major theme of ecological research over the last several decades. It is abundantly clear that the spatial configuration of habitat patches in a landscape influences ecological processes. Understanding how landscape structure affects the movement and dispersal of organisms, and how this in turn shapes the abundance and distribution of species across space, is a longstanding goal of landscape ecology. Ecological models have long used diffusion to represent the dispersal and movement of organisms in landscapes. However, the dispersal and movement of organisms is inherently a stochastic process, which diffusion can only approximate. Here, we show that diffusion models of dispersal can generate highly synchronized dynamics across space in cases where stochastic dispersal does not, and that there are two regimes (dispersal and demographic) for the primary source of variability in abundances across habitat patches. We do this by presenting a spatial graph model of landscape connectivity, and we emphasize the potential value of simulation models for analysis and planning of landscape structure going forward.