Factors affecting the occurrence of bark- and wood-boring beetles on Scots pine logging residues from pre-commercial thinning

A total of480 Scots pine (Pinus sylvestris L.) trees felled during pre-commercial thinning in a single stand in the Drahanska Highlands in the Czech Republic were examined for the occurrence of bark- and wood-boring beetles. Thinning was performed on different dates during 2006 and 2007 (February, May, August and November). Half of the felled trees were cut into 1 m-long sections, and the rest were left whole. The fauna inhabiting the logging residues were investigated by peeling off the bark ofthe felled trees during the first six months of the vegetative period following felling. The studied logging residues hosted species-rich assemblages of bark- and wood-boring beetles (28 species identified), including numerous populations of several pest species (Pityogenes chalcographus, Tomicus minor and Tomicus piniperda). The occurrence of species was significantly affected mainly by the part of the tree and its diameter and bark thickness and by the felling date and post-felling cutting of the trees.