Saproxylic Beetles in Standing Dead Wood Density in Relation to Substrate Sun-exposure and Diameter

摘要: Species-specific densities of saproxylic beetles in cut 4-m high, medium to large diameter stumps spruce, birch, aspen and oak were monitored for 7 years after cutting, by trapping emerging insects within seasonally applied net enclosures. A total 47,038 individuals, representing 316 beetle species including 40 red-listed species, recorded. Densities 86 modelled relation stump measured levels sun-exposure. Two thirds the favoured semi- or fully exposed substrates, while one third performed better shade. Few seemed be specifically adapted semi-exposed conditions. Diameter was generally less importance than exposure, similar numbers substrates. Group mean exposure calculated from means per individual groups non-modelled non-red-listed respectively. This indicates that proportions found models are representative diverse regional fauna utilise high early stages decay. The results suggest sun-exposed dead wood substrates generated retained managed forest landscapes potentially important many species. However, stands unmanaged self-thinning successions deciduous trees, as well substantial areas old-growth spruce-forests also necessary address wide spectrum beetles.