Fragmentation and metapopulations

Fragmentation can cause a once continuously distributed population to become a metapopulation. When habitat becomes fragmented and/or species are poor dispersers colonisation rates can decline so that habitat patches become devoid of certain species. Habitats can remain unoccupied by these species for several generations.

The number of species converted to metapopulations increases with fragmentation of habitat into small patches.

Whilst some degree of extinctions and recolonisations are common, fragmentation of habitat can cause metapopulation dynamics to become more pronounced. This means that in these fragmented landscapes extinction and recolonisation are important elements of survival.

Problems arise in the stability of the metapopulation if movement between subpopulations is restricted. Corridors (connectivity) are important for allowing movement across a habitat, which is less suitable.

The extinction rate will also depend on habitat quality and area of patch. High quality patches are better for survival as are larger patches. Smaller patches will have a higher extinction probability.

These interrelationships and flows across the landscape are quite complex. Much work still needs to be done on linking patterns in the landscape to population dynamics if we are to understand the relationships more proficiently.

Do either Kellerberrin or New England have a problem with metapopulations or the spatial arrangements of habitat patches?