Phaeocryptopus gaeumannii

is the ascomycete fungus that causes SNC disease. This fungus is native throughout the range of its host, Douglas-fir, and until the mid-1980s was considered an unimportant and minor pathogen. Annual aerial surveys conducted by the Oregon Department of Forestry (ODF) estimate that more than 300,000 acres have been impacted by the fungus each year since 2006, a consistent increase since aerial surveys began in 1996. Disease is most damaging close to the coast, and severe disease has been associated with several climatic and topographic variables, including abundant spring leaf wetness from precipitation and fog, mild temperatures in the winter and spring, and low-elevation valleys. Much of the current research is focused on assessing the impacts of soil and foliage nutrition on Swiss needle cast disease development and severity.