title: Age and size of European saltmarshes and the population genetic consequences for ground beetles.
abstract: Enzyme and dispersal polymorphisms of the saltmarsh carabid beetles Pogonus chalceus and Dicheirotrichus gustavii were studied in European populations varying in size and in isolation in space and time. D. gustavii, a constantly fullwinged species, has a larger genetic diversity and a smaller genetic differentiation between populations than the wing-polymorphic P. chalceus. Clear relationships between population or site characteristics and genetic structure were not observed, except for the special position taken by some small populations in both species. The dispersal power of P. chalceus in small populations is larger than in large populations, suggesting that these populations are unstable and/or young. Small populations, however, do not always show a lower genetic diversity than large populations, as would be expected from genetic drift. Dispersal power in P. chalceus declines with increasing age of the saltmarsh, probably due to continuous emigration of winged individuals. Age and size of saltmarshes, although difficult to study independently, both appear to be important in determining the genetic structure of saltmarsh beetles. Maximum diversity in both parameters is therefore recommended as an optimal nature conservation strategy.
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium Fax: (32)26274132; e-mail: kdesender@kbinirsnb.be, , , , , , BE.
authors.forename: Konjev
authors.initials: K
authors.lastname: Desender
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium Fax: (32)26274132; e-mail: kdesender@kbinirsnb.be, , , , , , BE.
authors.forename: Thierry
authors.initials: T
authors.lastname: Backeljau
authors.affiliation: Laboratory of Animal Ecology, University of Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium, , , , , , BE.
authors.forename: Koen
authors.initials: K
authors.lastname: Delahaye
authors.affiliation: Laboratory of Ecology and Aquaculture, Katholieke Universiteit Leuven, Naamsestraat 59, B-3000 Leuven, Belgium, , , , , , BE.
authors.forename: Luc
authors.initials: L
authors.lastname: De Meester
keywords: Biodiversity; Genetic differentiation; Habitat fragmentation; Key words Ground beetles; Wing polymorphism