Role of forest site type in determining bacterial and biochemical properties of soil

The aim of the present study was to investigate the effect of forest site type on the bacterial and biochemical properties of the soil. Data for counts, diversity, and composition of bacterial communities, as well as soil enzymatic activity, was used for the assessment. A determination of the relationships between the parameters was also performed. Soil samples were collected in the Stare Jabłonki Forest Division (north-eastern Poland, Central Europe) from four sites: fresh coniferous forest (Fc), fresh mixed coniferous forest (Fm), fresh mixed forest (Mf), and moist mixed forest (Mm). The tested soils showed significant differences in enzyme activity and microflora. Organotrophic bacteria and actinobacteria proliferated the most in soil from fresh mixed coniferous forest. Organotrophic bacteria grew faster than actinobacteria in the soil, indicating that the former were represented by r-strategists, and the latter – by K-strategists. The soil sampled from site Fc2 (fresh coniferous forest) had the highest values of the diversity index. Alphaproteobacteria (phylum Proteobacteria) were the dominant bacterial class in the soils, followed by Actinobacteria (phylum Actinobacteria) and Acidobacteriia (phylum Acidobacteria). Phyla Proteobacteria, Actinobacteria, and Acidobacteria were most abundantly represented by genera Rhodoplanes, Mycobacterium, and Candidatus Solibacter, respectively. According to the biochemical soil quality index (BA), the soil sampled from site Fc2 (fresh mixed coniferous forest) was the most fertile. The study demonstrates that microbial and biochemical parameters of the soil can serve as an accurate indicator of the status and health of forest ecosystems.