Topic 14: Metapopulations

Metapopulations

population consisting of many smaller local populations that interact.

Populations in larger patches have:

greater populations sizes

more resources (higher K)

greater habitat heterogeneity

greater genetic variability

lower local extinction rates

greater population stability

Stable equilibrium

constant number occupied patches

Source populations

relatively high k (large size, good quality)

• may act as source to neighboring patches

• (emigration > immigration, b>d)

Sink populations

relatively low K (small size, poor quality)

• receives individuals, but has negative growth rate

• (immigration > emigration, d > b)

Landscape models

a conceptual and mathematical framework that accounts for:

• differences of habitat size and quality

• connectivity/ dispersal between habitats

Conservation

Captive breeding

Creation of larger patches

Dispersal corridors

Increase dispersal

Reduce local extinction

ex: corridors, wildlife bridges, linkages between patches.

Epidemiology

Source populations = infected

Sink populations = immunity

dispersal = transmission mode/vector

patch quality = susceptibility