Forest soils planted with longleaf pine were sampled across five disturbance classes and over five depths and analysed to evaluate whether harvesting activities had an impact on soil microbial community structure. Because of the importance of nitrogen in soils, the three major nitrogen cycling guilds of microorganisms (nitrogen fixers, denitrifiers and nitrifiers) were targeted in this study. PCR molecular analysis was used to target the functional genes for denitrification (nirS/nirK), nitrogen fixation (nifH) and nitrification (amoA). There appeared to be little impact of harvesting activities on nitrogen fixers. However, dentrifiers exhibited community change with apparent increases in nirS/nirK in the higher disturbance class soils. Nitrifiers were below detection at all sites. These preliminary studies suggest that some harvesting activities may lead to soil N loss because denitrifier populations are stimulated. Future studies will analyse the impact of harvesting activities on soil microbial activities.