2 - Biodiversity in marginal areas
Published online by Cambridge University Press: 06 July 2010
Summary
BIODIVERSITY AT THE PERIPHERY
Biodiversity has now become an integral element in environmental monitoring. Much attention has been given in recent years to the species-rich areas of the Earth, as there is an obvious concern that regions that contain so much of the world's evolutionary heritage do not become biologically impoverished. There is, however, a strong case for giving attention to marginal areas in the preservation of biodiversity even if the numbers of species that they contain cannot compare with the biological hotspots of the world.
Marginal areas, as has already been pointed out, are areas where climatic change is liable to cause disturbance either in location or the nature of the vegetation that survives in these potentially labile localities. Historically, they are areas that will have experienced climatic change in the past and therefore the species that live in these areas may be pre-adapted to climatic change and should therefore be considered particularly relevant in the study of species responses to fluctuating environments. It has been argued (Safriel et al., 1994) that peripheral populations have to be genetically more variable than those from core areas, since the variable conditions induce fluctuating selection, which maintains high genetic diversity. Alternatively, due to marginal ecological conditions at the periphery, populations there are small and isolated: the within-population diversity is low, but the between-population genetic diversity is high due to genetic drift.
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- Plants at the MarginEcological Limits and Climate Change, pp. 29 - 60Publisher: Cambridge University PressPrint publication year: 2008