We present results of a study testing the response of two saprophytic white-rot fungi species, Pleurotus pulmonarius and Coriolus versicolor, to charred biomass (charcoal) as a growth substrate. We used a combination of optical microscopy, Scanning Electron Microscopy (SEM), elemental abundance measurements, and Isotopic Ratio Mass Spectrometry (IRMS) to investigate fungal colonization of control and incubated samples of Scots Pine (Pinus sylvestris) wood, and charcoal from the same species produced at 300°C and 400°C. Both species of fungi colonize the surface and interior of wood and charcoals over time periods of less than 70 days, however distinctly different growth forms are evident between the exterior and interior of the charcoal substrate, with hyphal penetration concentrated along lines of structural weakness. Although the fungi were able to degrade and metabolize the pine wood, charcoal does not form a readily available source of fungal nutrients at least for these species under the conditions used in this study.