Speaker
Description
Habitat fragmentation, often driven by human activities, alters ecological landscapes by disrupting connectivity and reshaping species interactions. In such fragmented environments, habitats can be modeled as networks, where individuals disperse across interconnected patches. We consider an intraspecific competition model, where individuals compete for space while dispersing according to a nonlinear random walk \cite{Asllani2018}, capturing the heterogeneity of the network. The interplay between asymmetric competition, dispersal dynamics, and spatial heterogeneity leads to nonuniform species distribution: individuals with stronger competitive traits accumulate in central (hub) habitat patches \cite{BarabasiAlbert1999}, while those with weaker traits are displaced toward the periphery. We provide analytical insights into this mechanism, supported by numerical simulations, demonstrating how competition and spatial structure jointly influence species segregation. In the large-network limit, this effect becomes extreme, with dominant individuals disappearing from peripheral patches and subordinate ones from central regions, establishing spatial segregation. This pattern may act as a potential precursor to both speciation and diversity, as physical separation can reinforce divergence within the population over time and potentially support coexistence at the landscape scale.
Bibliography
@article{Orgeron2026,
author = {Orgeron, James Austin and Asllani, Malbor},
title = {Habitat fragmentation promotes spatial scale separation under resource competition},
journal = {Journal of Theoretical Biology},
volume = {621},
pages = {112367},
year = {2026}
}
@article{Asllani2018,
author = {Asllani, Malbor and Carletti, Timoteo and Di Patti, Francesco and Fanelli, Duccio and Piazza, Fabio},
title = {Hopping in the Crowd to Unveil Network Topology},
journal = {Physical Review Letters},
volume = {120},
pages = {158301},
year = {2018}
}
@article{BarabasiAlbert1999,
author = {Barab{\'a}si, Albert-L{\'a}szl{\'o} and Albert, R{\'e}ka},
title = {Emergence of Scaling in Random Networks},
journal = {Science},
volume = {286},
number = {5439},
pages = {509--512},
year = {1999}
}
