Jörg Müller (Bavarian forest National Park, Univ. of Würzburg, Germany): Windstorms and bark beetles – a chance and challenge for managers and conservationists
Increasing natural disturbances in conifer forests worldwide complicate political decisions about protected area management and beyond. A global overview has shown that post-disturbance removal of trees – the so called salvage logging - is more and more common in protected areas, particular in Europe and Asia. The two main motivations to remove trees in protected areas are timber and pest control. For the latter, bark beetles are the main target groups of such interventions. Investigating the effects of a benign-neglect strategy as well as political motivated salvage logging in Bohemian Forest with two national parks the Bavarian Forest National Park, Germany, and Sumava Nationalpark, Czech Republic, provided new insight in the role of the European spruce bark beetle, windthrows and post-disturbance logging on biodiversity, rare species and community assembly patterns. Overall, bark beetle infestation increased alpha diversity of many taxa. The same was true for red-listed species. Salvage logging of windstorms for bark beetle control consistently reduced richness of wood-depending taxa from lichens, beetles, fungi and birds and changed the natural assemblage pattern. For windblown trees highly attractive for bark beetles the method of debarking was further developed with bark-scratching providing a new method with reduced negative effects on biodiversity, while sufficient reduction of the target bark beetle. Experiments and multispecies approaches including dark diversity revealed new evidence for the complex response of communities to natural and anthropogenic disturbances. In summary the results show that landscape wide outbreaks of the European spruce bark beetle are certainly critical from an economic perspective, but not from a biodiversity and conservation perspective. Therefore, salvage logging must be banned from protected areas, except for relatively limited areas where there is a clear risk to humans or private property.