Speaker
Description
Understanding how dispersal affects the total biomass of fragmented populations is a central problem in ecology. For the simplest metapopulation network, consisting of two patches, the continuous-time case with logistic local growth was completely described in \cite{gao2022}. In contrast, the analogous discrete-time problem has remained largely unresolved, with previous work describing only the low-dispersal regime.
For two-patch metapopulations, we first present a complete characterization of the biomass response to dispersal in a discrete-time Beverton-Holt model. We then show how the picture changes when local dynamics are modeled by other population maps, such as the Ricker map: in contrast with the Beverton-Holt case, qualitatively new response scenarios can arise, highlighting the role of the shape of local recruitment functions. Finally, we turn to multi-patch metapopulations and discuss how both patch number and network topology affect biomass responses. Exhaustive numerical analyses show that moving from two to three patches can substantially increase the range of possible scenarios, both in continuous and discrete time, while theoretical results show that adding connectivity does not always increase biomass at low dispersal rates, refuting previous claims in the literature.
Bibliography
@article{franco2024new,
author = {Franco, D. and Per{\'a}n, J. and Segura, J.},
title = {New insights into the combined effect of dispersal and local dynamics in a two-patch population model},
journal = {Journal of Theoretical Biology},
volume = {595},
year = {2024},
pages = {111942}
}
@article{gao2022,
author = {Gao, D. and Lou, Y.},
title = {Total biomass of a single population in two-patch environments},
journal = {Theoretical Population Biology},
volume = {146},
year = {2022},
pages = {1--14}
}
@article{grumbach2023,
author = {Grumbach, C. and Reurik, F. N. and Segura, J. and Franco, D. and Hilker, F. M.},
title = {The effect of dispersal on asymptotic total population size in discrete- and continuous-time two-patch models},
journal = {Journal of Mathematical Biology},
volume = {87},
year = {2023},
pages = {60}
}
@article{segura2026,
author = {Segura, J. and Marv{\'a}, M. and Franco, D.},
title = {Dispersal in multi-patch metapopulations: The impact of patch number and network topology},
journal = {Journal of Theoretical Biology},
volume = {619},
year = {2026},
pages = {112331}
}
