The impacts of clear-cutting and clear-cutting followed by prescribed burning on soil microbial diversity and community structure were assessed using sole-carbon-source utilization. Microorganisms were washed from organic and mineral soil samples and used to inoculate Biolog Gram-negative microplates. Patterns of colour development were analysed using principal component analyses and calculation of Shannon diversity indices. No differences between treatments were detected when individual samples were used. However, both organic and mineral soil samples from the burned plot showed lower microbial diversity when pooled samples were examined.