- Effects of extinction and recolonisation dynamics on genetic differentiation of plant metapopulations on dynamic stony banks along the Common Meuse
A metapopulation is a collection of spatially discrete subpopulations that can exchange individuals through migration. The different subpopulations of the metapopulations are prone to extinction and subsequent (re)colonization events. These typical extinction –recolonization dynamics of a metapopulation have also major consequences for the genetic structure within and between the subpopulations of the metapopulation. The traditional island model of S. Wright (1943) is no longer sufficient to describe the genetic structure of a metapopulation. A very essential issue for the degree of genetic differentiation between the subpopulations of a metapopulation is that the subpopulations are prone to extinction and subsequent recolonization or founder events. Because founder populations are generally relatively small, they are prone to extra genetic drift that may cause extra divergence between subpopulations of the metapopulation. Theoretical studies have shown that the extent to which there is genetic differentiation in a metapopulation depends on the number of effective colonists, the number of migrants between existing populations and the chance on common origin of the colonizing individuals (Wade & McCauley 1988, Whitlock & McCauley 1990). There is, however, almost no empirical evidence related to the effects of colonization and extinction dynamics on the temporal evolution of the genetic structure of a plant metapopulation (but see Giles & Goudet 1997, McCauley et al. 1995, Jacquemyn et al. 2004). An important reason for the lack of this kind of studies is of course the difficulty that is associated with finding the appropriate study system with frequent extinctions and subsequent recolonization events. In this project we study the metapopulation dynamics of some pioneer species on stony banks along the Meuse valley. These stony banks are characterized by flooding during winter and hence the established plant populations are the subject of recurrent extinction and colonization events.
created:2011-12-14 14:18:59 UTC, source:web
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