Abstract. 1. European Beech (Fagus sylvatica) is the natural dominant tree species in many forests across Europe. Despite Europe’s global responsibility for these forests, the correct conservation strategies are still a matter of debate. In particular, it remains controversial whether high conservation efforts should be directed towards beech forests, owing to the small number of insects that are Fagus specialists, and at what spatial scale conservation should take place.
2. To provide evidence for this discussion, we compiled saproxylic beetle data from 1115 flight-interception traps in eight countries and addressed two main questions: (i) what percentage of central European species can be expected in beech-dominated forests? and (ii) which are the important spatial scales for the conservation of biodiversity in beech-dominated forests?
3. We included six spatial scales in our analysis: among traps, forest stands, forest sites, low/high elevations, oligo/eutrophic soils, and European bioregions.
4. By extrapolating species numbers, we showed that 70% of the central European saproxylic beetle species can be expected in beech-dominated forests. Multiplicative β-diversity partitioning revealed the forest site level as the most important diversity scale for species richness, particularly for red-listed and rare species, followed by elevation and bioregion.
5. We conclude that beech-dominated forests form a useful umbrella for the high species diversity of central European saproxylic beetles. Conservation activities, such as protecting areas or increasing dead wood, should be undertaken in as many forest sites as possible, at different elevations, and in different bioregions. For this, the Natura 2000 net may provide the most useful template.