Interacting populations in heterogeneous environments

Détails

ID Serval
serval:BIB_F6E333D8B519
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Interacting populations in heterogeneous environments
Périodique
Ecological Modelling
Auteur(s)
Vuilleumier S., Possingham H.P.
ISSN
0304-3800
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
228
Pages
96-105
Langue
anglais
Résumé
To optimally manage a metapopulation, managers and conservation biologists can favor a type of habitat spatial distribution (e.g. aggregated or random). However, the spatial distribution that provides the highest habitat occupancy remains ambiguous and numerous contradictory results exist. Habitat occupancy depends on the balance between local extinction and colonization. Thus, the issue becomes even more puzzling when various forms of relationships - positive or negative co-variation - between local extinction and colonization rate within habitat types exist.
Using an analytical model we demonstrate first that the habitat occupancy of a metapopulation is significantly affected by the presence of habitat types that display different extinction-colonization dynamics, considering: (i) variation in extinction or colonization rate and (ii) positive and negative co-variation between the two processes within habitat types. We consequently examine, with a spatially explicit stochastic simulation model, how different degrees of habitat aggregation affect occupancy predictions under similar scenarios. An aggregated distribution of habitat types provides the highest habitat occupancy when local extinction risk is spatially heterogeneous and high in some places, while a random distribution of habitat provides the highest habitat occupancy when colonization rates are high. Because spatial variability in local extinction rates always favors aggregation of habitats, we only need to know about spatial variability in colonization rates to determine whether aggregating habitat types increases, or not, metapopulation occupancy. From a comparison of the results obtained with the analytical and with the spatial-explicit stochastic simulation model we determine the conditions under which a simple metapopulation model closely matches the results of a more complex spatial simulation model with explicit heterogeneity.
Mots-clé
Metapopulation models, Heterogeneity, Habitat distribution, Population viability, Occupancy, Spatially explicit
Web of science
Création de la notice
19/01/2012 9:34
Dernière modification de la notice
20/08/2019 17:23
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