The objective of this study was to compare chemical and microbial properties of sandy mine soils under young Scots pine, silver birch, and mixed pine-birch forest stands. The measured properties included the contents of organic C (C_{org}) and total N (Nt), the C_{org}-to-N_{t} ratio, pH, microbial biomass, basal respiration, and activities of dehydrogenase, acid phosphomonoesterase, and urease. Community level physiological profiles (CLPPs) of soil bacteria were determined with Biolog® test and genetic profiles with the DGGE method. Scots pine and silver birch did not affect the C_{org} and N_{t} contents in the studied mine soils. The soil under birch contained larger and more active microbial biomass than the soil under pine. Under the mixed stand, most of the microbial properties were intermediate between the pine and the birch stand. The DGGE profiling indicated different composition of soil bacteria under the birch stand compared to the other stands. Differences in CLPPs were less pronounced, probably due to functional redundancy of soil bacteria.