Ground beetles of Lauzelle Forest (Belgium, Walloon Region): community characterization and study on mean individual biomass as an indicator of forest ecological state

Details

Supervisors

Hance, Thierry

Faculty

Faculté des sciences

Degree label

Master [120] en biologie des organismes et écologie, à finalité approfondie

Abstract

The world is currently facing a sixth mass extinction caused mainly by human activities. This biodiversity crisis is affecting many organisms, some of which are particularly useful because of their status as bioindicators. This is the case of carabid beetles, whose many qualities make them a simple and highly effective study model. Carabid beetles are recognised as good bioindicators for monitoring ecological succession, particularly in forest environments following wood production activities. This study follows on from the last carabid inventory carried out in the wood over 40 years ago. Its aim is to reassess the diversity of carabid beetles in the Lauzelle Forest (temperate woodland in Belgium) by characterising the distribution of carabid communities and biomass using different biotic and abiotic environmental variables. Carabid beetles were trapped with pitfall traps laid out across the wood in eight different forest habitat types (birch, beech, oak, mixed oak and beech plots, heathland, forest edges, pine tree plots and protected area). They were then weighed to obtain an individual mean biomass value (MIB) per trapping station. The results showed that there were three communities of carabid beetles within the wood and that their distribution depended on the gradients of humidity and openness of the habitat. The measures of abundance, species richness and MIB are influenced by different environmental variables. The MIB also revealed a positive effect of conservation measures undertaken within a plot on carabid beetles and ecological succession. A closer look at certain characteristics of the different species shows that forest specialist species are less abundant than generalist species and open habitat species. Although most of the results obtained are in line with the literature, some contradictions highlight the impact of forest management on carabid beetles and, moreover, on ecological succession within the wood.