An updated Red List of the ground and tiger beetles (Coleoptera, Carabidae) in Flanders (Belgium)

摘要

An analysis of the long term dynamics of ground and tiger beetles in Flanders permitted to update the first documented Red List of 1995.During the past 10 years, the number of records on these beetles nearly doubled, mainly because of several large scale regional studies and monitoring projects. The compilation of this new Red List of carabid beetles in Flanders is mainly based on two criteria: a trend criterion (degree of decline) and a rarity criterion (actual distribution area). For some species occurring in one or only a few small and strongly isolated populations and/or species that are threatened because they are only found in one particularly threatened habitat or because they are constantly brachypterous (wingless), a third criterion best professional judgement, is additionally used. To update the previous Red List, we now adopted 1980 as pivot point (instead of 1950), because this permitted to detect more recent changes in distribution. We also changed from the usual 10 km x 10 km UTM grid cells to 5 km x 5 km UTM grid cells. However, due to some differences in mapping intensity in the two compared periods, a straightforward comparison of the number of grid cells in which each species was recorded, appears inappropriate and therefore a correction factor is used. A list is compiled of all species, including those new for landers (since 1980), as well as those that have disappeared (no more records since 1980). We discuss the number of carabid species found in the two periods and give comments on rarity and trends in species distributions. Of the 382 species ever recorded in Flanders, 35% appear to be threatened at this moment in one way or another and their distribution is clearly linked to a number of severely threatened habitats.