Habitat models of wood-inhabiting fungi along a decay gradient of Norway spruce logs

Modern molecular techniques provide a comprehensive and high-resolution window into complex systems that are difficult to study with traditional macroscopic techniques. We applied culture-free DNA extraction and 454-pyrosequencing to study the fungal microflora of decaying Norway spruce (Picea abies [L.] Karst.) logs in five unmanaged boreal forests. Fungal diversity and wood density were inversely related, i.e., OTU richness generally increased as the log became increasingly decomposed. According to generalized additive mixed models white-rot fungi (e.g., Phellinus nigrolimitatus) and members of Hyphodontia did not show a clear response to the wood-density gradient, whereas Phellinus viticola and brown-rot fungi (e.g., Fomitopsis pinicola, Antrodia serialis, Coniophora olivaceae) peaked during intermediate decay and mycorrhizal fungi (e.g., Piloderma, Tylospora, Russula) increased in the later stages. This information on fungal habitat requirements facilitates development of management practices that preserve fungal diversity in managed forests.