The occurrence of early-arriving saproxylic beetles on Scots pine logging residues generated by thinning

Abstract

The occurrences of early-arriving saproxylic beetles were examined on 1,200 fragments of Scots pine (Pinus sylvestris L.) logging residues generated by thinning in a single stand in the DrahanskĂĄ Highlands in the Czech Republic. The felling was carried out on four dates in 2006 (February, May, August, November). The occurrence of early-arriving saproxylic beetles was investigated by peeling off the bark of logging residues during the first six months of the vegetative period following the felling. Beetle occurrence was significantly affected by felling date, logging residue type (trunk fragment, or branch thinner or thicker than 1 cm) and diameter. Only 16 species of early-arriving saproxylic beetles were found. The results indicate that the shaded and fairly uniform logging residues from thinning are probably of minor importance for the conservation of saproxylic beetles, but their presence might increase the risk of certain pest outbreaks (particularly, Pityogenes chalcographus [Linnaeus]). As an alternative to the removal of logging residues, the risk of the multiplication of this pest can be minimised if thinning is carried out in August (and probably also in September and October).