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Published byGiles Shaw Modified over 9 years ago
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Metapopulation Dynamics Metapopulation structure: Demes linked via dispersal Local scale: colonization, extinction Regional scale: Occupation frequency global extinction
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University of Kentucky
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Extinction, Re-colonization Dynamics
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University of Idaho
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Spotted Owl: Lahaye et al., 1994, Oikos 63:775
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Metapopulation
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Colonization balances Extinction
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Metapopulation Dynamics p(t): proportion patches occupied, time t Spatially implicit (ignore spatial structure): All patches equally linked
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Metapopulation Dynamics Predict: p*, equilibrium occupation frequency Equilibrium: colonization = extinction Closed metapopulation (internal colonization) Open metapopulation (island-mainland)
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Closed Metapopulation
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Open Metapoulation Colonization: propagule rain from mainland x frequency of open sites Extinction: linear in occupied-site frequency
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Open Metapoulation
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Metapopulation Dynamics Assume: Patches identical: colonization, extinction Each patch direct link to all others c, m, e constants Total number of patches large
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Patch Size, Inter-Patch Distance
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Migration: Mass, Temperature
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Metapopulation Extinction Local extinction versus global extinction Consider spatial synchrony across demes Local densities correlate positively Moran effect Dispersal and “simpler” dynamics
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Metapopulation Extinction High synchrony Global extinction Asynchrony Regional persistence Chaos: “nearby trajectories diverge” Can increase local extinction; reduce global extinction
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Global Synchrony
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