Effects of prescribed burning on carabid beetle diversity in coastal anthropogenic heathlands

摘要

European anthropogenic coastal heathlands are threatened by the cessation of traditional management practices. Fire has a long history in the management of this landscape, and its effect on various species groups has been investigated in previous studies. However, the resolution of these studies is generally rather coarse and is biased towards plants. In this study, we investigate the species diversity and composition of carabid beetles over a 22-year chronosequence of time since last fire in a coastal heathland in western Norway. We show that burning increases alpha species richness, and is particularly important for the richness of typical open habitat species. Our results also show that there are clear compositional differences between assemblages along the chronosequence, supporting the value for landscape scale biodiversity of rotational burning. Species richness is also increased by a higher species turnover between consecutive years in patches that have been burnt recently as compared to patches that have not been burnt for a long time. We conclude that burning is important in maintaining carabid diversity in anthropogenic heaths, and that prescribed burns should aim to create a mosaic of different burn years, preferably with a bias toward younger stages.