acrylic on canvas
60cm x 60cm
Iain White, 2009
Non-equilibrium metapopulations comprise local populations that are effectively isolated from one another. Recolonisation of vacent patches, if it occurs at all, is too slow to offset the rate of extinction. Consequently regional population gradually declimes as individual local populations go extinct and are not replaced.
This model must apply to many rare species that have become confined to isolated habitat patches that are too remote from each other to allow any realistic chance of natural recolonisation. It is likely to apply most rigidly to species that are doubly disadvantaged by requirements tha are specific to scarce and localised habitats and possess limited powers of dispersal.
Many invertebrates fit this description. For example, many scarce butterflies in the UK with exacting habitat requirements tend to form small closed populations suggesting limited dispersal between them.
