Jean-Pierre Maelfait

Long term dynamics of carabid beetles in Belgium: a preliminary analysis on the influence of changing climate and land use by means of a database covering more than a century

This contribution is a first attempt to analyze the long term dynamics of some selected carabid genera in Belgium. A method is developed which corrects the data for differential sampling intensities per period of time and which analyzes the corrected time trend patterns. The results on species level are then compared with trends of climatic as well as land use changes in a first attempt to unravel the relative importance of both types of phenomena in the long term dynamics of beetles in Belgium. We conclude that especially during recent decades a few common species have become relatively more common at the expense of a larger number of rare species which became even more rare. This change of the carabid fauna can be interpreted as resulting from the loss of natural and semi-natural open habitats, especially since 1950, and from the intensification of agriculture.