EFFECTS OF LANDSCAPE DYNAMICS ON THE METAPOPULATION OF A GROUND BEETLE (COLEOPTERA, CARABIDAE) IN A HEDGEROW NETWORK

A study was made on the effects of recent landscape history on the sub divided populations of the carabid species Abax parallelepipedus in a hedgerow network. The distribution of this species on the site was str ongly related to landscape connectivity. Occupied habitats are the lea st isolated from a source of colonizers. Connectivity measured as the distance to the nearest occupied site calculated along the hedgerow ne twork and weighted by the quality of their wooded elements (WD) is a g ood predictor of the distribution of Abas parallelepipedus in the stud y area. Many landscape changes have occured between 1952 and 1993 both in the structure and the quality of the wooded network in this area. As a consequence, functional isolation between sample sites has increa sed by 28% since 1952. The results indicate that the current distribut ion of Abax parallelepipedus in the network is significantly better re lated to the 1952 landscape than to the current one. This may indicate the existence of a time lag between landscape changes and the reactio n of Abax parallelepipedus to such modifications. The relationship rem ains the same over a brood range of spatial scales. This result should lead to the consideration of landscape history in species distributio n analysis. (C) 1998 Elsevier Science B.V. All rights reserved.