Microfungal variations relative to post-fire changes in soil environment.

Soils of three Picea mariana-Cladina stellaris woodland sites, aged 2, 104 and 137 years after fire, were sampled at 3 cm intervals to 9 cm depth for soil microfungi. Mortierella, Mucor, Penicillium and Trichoderma were the most frequently isolated genera. The species composition of the microfungi remained much the same across the age gradient. Direct and indirect gradient analyses of the microfungal species and 14 soil environmental factors indicate that the frequencies of occurrence of the microfungi are influenced by environmental factors primarily related to the build-up of the organic layer and its destruction by fire.