Where are they hiding? Testing the body snatchers hypothesis in pyrophilous fungi

Abstract Pyrophilous fungi produce sporocarps after a fire but little is known about their ecology prior to or after a fire event. Recently, the body snatchers hypothesis was proposed that suggests some post-fire fungi form endophytic and/or endolichenic relationships with plants and lichens. To test the body snatchers hypothesis, bryophyte, lichen, club moss, and soil samples were collected from unburned and mixed-intensity burned areas 1–2 y after a 2016 wildfire in the Great Smoky Mountains National Park, and from unburned areas in four states outside the park. Samples were examined for the presence of pyrophilous fungi occurring as endophytes or in lichens using culture-dependent and culture-independent techniques. Culture-dependent methods isolated Pholiota highlandensis, a known pyrophilous fungus, from five bryophyte samples. Culture-independent methods identified 22 pyrophilous taxa from bryophyte, club moss, lichen, and soil samples across a range of geographical localities. The ‘body snatchers’ hypothesis is supported since many bryophyte, lichen, and club moss samples contained pyrophilous taxa suggesting that these fungi occur as endophytes and/or endolichenic fungi until a fire event triggers them to produce sporocarps.