Authors: Holmström, Lukas; Sjögren, Jörgen;Hekkala, Anne-Maarit ;Lindberg, Eva;Hjältén, Joakim Hjältén;

The global need for renewable energy has led to an increasing interest in bioenergy from boreal forests. While having a large potential for renewable energy, these forests also host a wide variety of species, several of which are red listed. The harvest of biomass for bioenergy may cause structural homogenization, potentially increasing the threat to biodiversity. In this project we have investigated the question if biomass extraction for bioenergy can be combined with biodiversity conservation in managed forests. Most research on effects of biomass harvest on biodiversity has taken place in final felling operations. In this study we turn our eyes toward thinning operations. We sampled the beetle community using flight intercept traps to evaluate how understory retention in thinning operations affect the beetle community in managed hemi boreal forests. Preliminary results indicate that the beetle community in plots that were thinned differ from plots that were left unharvested. Interestingly, species diversity increased after both thinning methods. This indicates that reduction of tree density affects both species composition and richness. We found no differences between the two different thinning methods, indicating that retention of understory has little or no effect on beetle assemblage.