Abstract
The habitat requirements of 11 beetle species associated with tree hollows were studied by correlating their occupancy with
characteristics of the oaks and the number of hollow oaks in each stand. The species richness was higher in trunks with a large girth
and in tree hollows with entrances situated high up on the trunks and not directed upwards. Several species occurred with higher
frequencies in larger stands, which suggests that these species are sensitive to habitat fragmentation. In some cases at least, the
present species richness may reflect higher densities of hollow trees in the past. It is therefore suggested that, in order to preserve the
rare fauna in old oaks, the stand size must be increased at many sites. In this study two species,Elater ferrugineus and Tenebrio
opacus, were absent from almost all stands with