Metapopulations

“above” “populations”“populations of populations that

locally go extinct and recolonize”

spatially subdivided populations existing in discrete habitat remnants or patches (islands) as a result of

habitat fragmentation (natural or anthropogenic)

Island Biogeography

MacArthur and Wilson1967

General theory that uses population ecology and genetics to explain how distance and area combine to regulate the balance among colonization, immigration, and extinction of isolated populations

Models assume static patchy matrices

HistoryLevins, R. 1969-70 “Metapopulation,” Extinction, winking dynamics,

patchy populationsPulliam, R. 1988 Sources & SinksHanski, I. & Gilpin Landscape elements

Relevance

population genetics, epidemiology, conservation biology

We want to discover where and when the pattern of available habitat patches in a landscape has detectable implications for dynamics or persistence of a population

Competition - patchiness provides for coexistencePredation - patchiness provides refugia for prey - patchiness provides refugia for pestsPopulation genetics - patchiness mediates gene flowConservation – habitat fragmentation and isolation of populations are

primary factors in decline of rare and endemic species

This semesterTwo presentations each, the first covering basic concepts and a second covering a case study

Basic concepts:

Case studies:

Definitions – Levins, Pulliam, Brown and Kodric, HarrisonAssumptions – of the three basic models (implicit, explicit, realistic)Criteria – dispersal, extinction, recolonization, etc.Equations – lambda, dp/dt = cp(1-p) – ep, Pmetapop’n persistnc = 1 - (e/c)Landscape – lacunarity, landscape connectivity, neutral landscapesGenetics – effective population size, migration, gene flow, etc.Conservation – endangered spp, habitat restoration, translocations and

reintroductions

Examples & case studies – Fritillary butterfly, Spotted owl, Kelp, etc.