Recruitment of saproxylic beetles in high stumps created for maintaining biodiversity in a boreal forest landscape

The active creation of coarse woody debris (CWD) has been suggested as a measure to preserve and restore biodiversity in managed forests. A common practice in Sweden is to create high stumps at final cutting. We evaluated the importance of high stumps for saproxylic (wood-dependent) beetles in a boreal forest landscape in central Sweden. The number of high stumps created on clearcuts was recorded and the beetle fauna under the bark of high stumps of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) was sampled. High stumps yielded only 0.13% of CWD volume and bark area in the landscape. Out of the 29 beetle species most frequently found in the landscape, high stumps were the major source of recruitment at the landscape level for only one, Hadreule elongatula (Gyllenhal). For the remaining 28 beetle species, less than 1% of the landscape's population occurred in high stumps on clearcuts. The abundance of H. elongatula increased with the area of the surrounding forest land that was covered by clearcuts within a radius of 1000 m. This is the first example of a saproxylic species associated with clearcuts, in contemporary forest landscapes, for which such an occurrence pattern has been documented.