Importance of natural disturbance for recovery of the rare polypore Antrodiella citrinella Niemelä & Ryvarden

Most strictly protected areas world-wide have been established in former commercial forests, but there is little evidence that this strongly advocated tool of conservation has had positive effects on endangered species in the short run of decades. One of the major reasons for the failure of habitat improvement in most of these reserves is a lack of natural disturbance. Consequently, only a few studies of species recovery in protected areas after natural disturbance are available. We demonstrate how natural dynamics in the oldest national park in Germany allows the area-wide recovery of the rare wood-inhabiting fungus Antrodiella citrinella. Our analyses showed that an increase of dead wood at >134–224 m3 ha−1, amounts known from primeval forests, allowed the fungus, which has barely survived as ‘living dead’ in two remnants of pristine forests, to spread from this small relict populations to the whole national park, within a radius of more than 30 km. Our result demonstrate that natural disturbance, even in former commercial forests, allowed the recovery of this rare species and fully supports the use of passive management in protected areas, even if natural dynamics often evokes debates on salvage logging.