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