Amendation of an oil sands tailings and a subalpine coal mine spoil, with either fertilizer, peat, or liquid sewage sludge, had significant effects on the occurrence of mycorrhizal fungi and spore numbers three years after the initial application. Glomus aggregatum and G. mosseae were the most common VA fungi associated with Agropyron trachycaulum on the two mine spoils. Chlamydospores of the E-strain ectomycorrhizal fungus were associated with Picea glauca on the subalpine spoil. In the oil sands spoil, VA fungal spores were only detected in the control and peat-amended plots. While there was no effect of amendation of the subalpine spoil on G. mosseae spore densities, spore numbers of G. aggregatum were highest in the peat- and lowest in the sewage-amended plots. Chlamydospore production by the E-strain fungus was highest in the control and fertilizer-amended plots with few spores collected from the sewage-amended spoil and none detected in the peat. A significantly greater percentage of spores of G. mosseae from the sewage-amended subalpine spoil occurred at the lower end of the size range for the species. By suppressing mycorrhizal spore production and by affecting spore size, sewage sludge application may have adverse effects on reclamation programs.