Biodiversity and species composition of carabidae in Irish coniferous forests: Additional insight from the use of paired sites in comparisons with the fauna of open habitats

Land-use change is one of the major components of global change. In Ireland, this change is largely due to the rapid expansion of the forestry sector at the present time. As much of the forest being planted comprises monocultures of exotic conifer species, this has led to concern about its effects on local biodiversity. In this study, the carabid fauna of forested and open habitats were sampled. The fauna of forested areas differed from that of open habitats both in terms of species composition and species diversity, but the forest carabid faunas also appeared to reflect the landscape in which they were found. In order to control for the effect of adjacent landscape and to verify and quantify the effects of afforestation on upland carabid faunas, a further sampling was carried out using a regime based on a matched pairs design using ten pairs of sites. Five of these sites were grasslands with adjacent forest plots and five were bogs with adjacent forests. This showed that species composition in forested areas was significantly different from that of open habitats but that species diversity did not differ significantly between open and closed habitats when differences in topography, altitude and other factors were eliminated.