EFFECTS OF SURFACE MINING ON THE MICROBIOLOGY OF A PRAIRIE SITE IN ALBERTA, CANADA

Abstract

The effects of surface mining for coal on soil respiration (CO 2 ), microbial biomass C, ATP levels, bacterial and actinomycete numbers, bacterial taxa, hyphal lengths, fungal taxa, N 2 fixation and decomposition potential were determined for a short-grass prairie site in southern Alberta, Canada. Soil respiration, microbial biomass C, ATP, actinomycete numbers, hyphal lengths and N 2 -fixing potential were significantly lower in the mined soil particularly when compared to the undisturbed topsoil. Bacterial numbers were, however, greater in the mined soil than in the unmined soil. The bacteria isolated from the undisturbed soil were dominated by Bacillus spp., coryneforms and non-pigmented Gram-negative rods, while those from the disturbed soil belonged mainly to the coryneform group. Mining also caused the fungal community to shift from one dominated by Chrysosporium-Pseudogymnoascus and sterile dark organisms to one dominated by Alternaria spp., Cladosporium spp., sterile dark forms and yeasts. Decomposition of filter paper, 24 mo after their placement in the field, was significantly faster on the disturbed site than on the undisturbed site. Key words: Surface mining, microbiology, prairie soil