Optimizing enrichment of deadwood for biodiversity by varying sun exposure and tree species: an experimental approach

1. The enrichment of deadwood is essential for the conservation of saproxylic biodiversity in managed forests. However, existing strategies focus on a cost-intensive increase of deadwood amount, while largely neglecting increasing deadwood diversity.

2. Deadwood objects, i.e. logs and branches, from six tree species were experimentally sun-exposed, canopy-shaded, and artificially shaded for four years, after which the alpha-, beta-, and gamma-diversity of saproxylic beetles, wood-inhabiting fungi, and spiders were analyzed. Analyses of beta-diversity included the spatial distance between exposed deadwood objects. A random-drawing procedure was used to identify the combination of tree species and sun exposure that yielded the highest gamma-diversity at a minimum of exposed deadwood amount.

3. In sun-exposed plots, species numbers in logs were higher than in shaded plots for all taxa, while in branches we observed the opposite for saproxylic beetles. Tree species affected the specie...