摘要
Fungal composition of Yukon soil samples consisted of 29 soil saprobes common to acidified forest,subarctic habitats.All of the fungi identified are psychrotrophs,capable of growth at both 4℃ and 20℃.Of these,a total of 17 fungi were found to be entomopathogenic by winter tick(Dermacentor albipictus)larval bioassays:Aspergillus flavus,Beauveria,namely B.bassiana,Mucor,Paecilomyces yielded>~70%larval mortality and the remainder,mostly Mortierella and Penicillium,averaged~40%larval mortality.Sites where elk(Cervus elaphus canadensis)are observed had an overall greater quantity,and diversity of entomopathogenic soil fungi than sites where elk are not observed.Greater diversity of fungi at elk-inhabited sites is likely a product of warmer soil microclimate(hillsides where elk are seen,lose snow earlier than other areas),animal presence,and increased nutrient enrichment.We conclude that Yukon soils contain fungi that naturally regulate populations of D.albipictus.All fungi are archived at the Wittenberg University Fungus Collection,Springfield,OH,USA.
