Metapopulations refer to spatially subdivided populations that exist in discrete habitat patches due to habitat fragmentation. They are made up of local populations that can go extinct and be recolonized. Island biogeography theory from MacArthur and Wilson explains how distance between patches and patch area affect colonization, immigration, and extinction rates of isolated populations. Metapopulation models assume static habitat patches and are relevant to population genetics, epidemiology, and conservation biology by showing how habitat patchiness can impact population dynamics, persistence, and gene flow.

1. 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)

2. Island Biogeography MacArthur and Wilson 1967 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

3. History Levins, R. 1969-70 “Metapopulation,” Extinction, winking dynamics, patchy populations Pulliam, R. 1988 Sources & Sinks Hanski, I. & Gilpin Landscape elements

4. 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 coexistence Predation - patchiness provides refugia for prey - patchiness provides refugia for pests Population genetics - patchiness mediates gene flow Conservation – habitat fragmentation and isolation of populations are primary factors in decline of rare and endemic species

5. This semester Two presentations each, the first covering basic concepts and a second covering a case study Basic concepts: Case studies: Definitions – Levins, Pulliam, Brown and Kodric, Harrison Assumptions – of the three basic models (implicit, explicit, realistic) Criteria – dispersal, extinction, recolonization, etc . Equations – lambda, dp/dt = cp(1-p) – ep, P metapop’n persistnc = 1 - (e/c) Landscape – lacunarity, landscape connectivity, neutral landscapes Genetics – effective population size, migration, gene flow, etc . Conservation – endangered spp, habitat restoration, translocations and reintroductions Examples & case studies – Fritillary butterfly, Spotted owl, Kelp, etc .