Wood-disk traps provide a robust method for studying spore dispersal of wood-decaying basidiomycetes

Spore traps consisting of disks containing monokaryotic mycelia as bait were tested to find a robust, long-time sampling method for studying dispersal of wood-decaying basidiomycetes. In total, 288 disks, 48 for each of six fungal species, were exposed 2 wk at 12 sites in northern Sweden. Both common and rare fungi were used, and the longest distance to a potential dispersal source exceeded 3 km. After 3-16 wk of incubation in the laboratory, the disks were investigated for spore hits. These were detectable both microscopically, by the presence of hyphal clamps, and macroscopically, by mycelial incompatibility zones. Spore traps resisted rain and freezing temperatures well, and spore hits from all species were found at all 12 sites. We argue that lengthy sampling makes it possible to detect low rates of spore deposition, aiding in the study of long-distance dispersal and dispersal of rare species. In addition, because several spore hits can be recognized in the same trap, spore deposition of wood-decaying fungi can be characterized with quantitative data.