Incollection,
Metapopulation Dynamics: From Concepts and Observations to Predictive Models
Metapopulation Biology, Academic Press, San Diego, (1997)
DOI: https://doi.org/10.1016/B978-012323445-2/50007-9
Abstract
Publisher Summary
This chapter focuses on metapopulation dynamics and metapopulations, essentially agreeing with the classical concept. In an increasing number of species, the spatial structure of populations is somehow consequential to their dynamics. Many studies have demonstrated that small populations in small habitat fragments have a high risk of extinction. Populations in nature exhibit continuous variation in their spatial structures. Species may persist at a spatial scale larger than the local population due to the “spreading of the risk” process, which involves movements among asynchronously fluctuating local populations. The consequences of this spreading of the risk in space will include a relative reduction in the amplitude of fluctuations of animal numbers in the entire population. However, it is not possible to have long-term persistence even in a metapopulation without some density dependence in local dynamics, given that local population sizes are restricted, as they always are, below some maximum value. Incidence of density dependence may be low in some persisting metapopulations, in comparison with the incidence of density dependence necessary for long-term persistence of isolated local populations. In metapopulations, the combination of long persistence time with little density dependence is associated with high turnover rate, and frequent local extinctions and colonizations.
