Dispersal, environmental forcing, and parasites combine to affect metapopulation synchrony and stability

Abstract : Dispersal can have positive and negative effects on metapopulation stability and persistence. One prediction is that high levels of dispersal synchronize density fluctuations between subpopulations. However, little is still known about how biotic and abiotic factors combine to modify the effects of dispersal rate on synchrony and metapopulation dynamics. In a fully factorial experimental design, we investigated the combined effects of (1) dispersal, (2) parasite infection, and (3) synchrony in temperature fluctuations on subpopulation synchrony, metapopulation instability, and minimum population size, in laboratory metapopulations of the ciliate Paramecium caudatum. Metapopulations, comprising two subpopulations linked by high or low levels of dispersal, were exposed to daily fluctuations in temperature between permissive (238C) and restrictive (58C) conditions. Infected metapopulations started the experiment with one subpopulation uninfected, while the other was infected at a prevalence of 5% with the bacterial parasite Holospora undulata. The temperature synchrony treatment involved subpopulations within a metapopulation following the same (synchronous temperatures) or different (asynchronous temperatures) temporal sequences. Population size was tracked over the 56-day experiment. We found that subpopulation density fluctuations were synchronized by high dispersal in infected metapopulations, and by synchronous temperatures in all metapopulations. Subpop-ulation synchrony was positively correlated with metapopulation instability and minimum metapopulation size, highlighting the multiple consequences of our treatments for metapopu-lation dynamics. Our results illustrate how parasites can generate dispersal-driven synchrony in non-cycling, declining populations. This ''biotic forcing'' via a natural enemy added to the temperature-dependent environmental forcing. We therefore conclude that predictions of metapopulation persistence in natural populations require simultaneous investigation of multiple ecological and epidemiological factors.
Liste complète des métadonnées

Littérature citée [40 références]  Voir  Masquer  Télécharger

https://hal.umontpellier.fr/hal-02353403
Contributeur : Alison Duncan <>
Soumis le : jeudi 7 novembre 2019 - 12:01:40
Dernière modification le : mercredi 13 novembre 2019 - 01:41:17

Fichier

Duncanetal2015Ecology.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

  • HAL Id : hal-02353403, version 1

Collections

Citation

Alison Duncan, Andrew Gonzalez, Oliver Kaltz. Dispersal, environmental forcing, and parasites combine to affect metapopulation synchrony and stability. Ecology, Ecological Society of America, 2015, 96, pp.284-290. ⟨hal-02353403⟩

Partager

Métriques

Consultations de la notice

10

Téléchargements de fichiers

8