Although primarily a saprotrophic fungus involved in the post @-@ fire breakdown of duff and coniferous roots , Geopyxis carbonaria have been shown to be capable of forming ectomycorrhizae with Norway spruce ( Picea abies ) . It had been demonstrated earlier in laboratory experiments that the fungus have a biotrophic interaction with lodgepole pine ( Pinus contorta ) . The hyphae of G. carbonaria was able to infect the cortex of the tree seedling , but did not penetrate the endodermis . These traits suggest that the fungus is a moderate pathogen , with limited ability to cause reductions in seed germination . Additionally , the fungus produce the enzyme polyphenol oxidase , and can break down the complex organic polymer lignin — feature characteristic of saprotrophic fungi . The formation of a rudimentary Hartig net , a characteristic of mycorrhizal fungi , indicated that G. carbonaria might be capable of forming mutualistic relationships under the right conditions . Vrålstad and colleagues suggest that its below @-@ ground association with spruce roots protect it from physical damage in the event of a fire , and the extensive fruitbody production after a fire may reflect " a successful fungal escape from a dying host where the fungus no longer can maintain its biotrophic association " .