Composition and activity of soil microbial communities in different types of temperate forests

The composition and diversity of forest soil microbial communities may be affected by the composition of plant communities and characteristics of soils. The objective of our study was to compare microbial properties of soils under various types of temperate forests. The samples were taken from soil A horizons under dry and mesic pine forests, acidophilus and fertile beech forests, hornbeam and oak dominated deciduous forests and ash dominated riparian forest. The samples were analysed for pH and the contents of organic C and total N, P, K, Ca, Mg and Mn. Microbial analyses included determination of microbial biomass, basal respiration, community level physiological profiles (CLPPs) measured by MicroResp (TM) method and phospholipid fatty acid (PLFA) profiles. The soil microbial communities under the pine forests were lower, less active and exhibited different CLPPs and PLFA profiles than those under deciduous forests. The PLFA profiles and CLPPs were correlated to each other revealing that the observed different metabolic abilities under the pine and deciduous forest types resulted from differences in taxonomic composition of soil microbial communities. The CLPPs and PLFA profiles depended on soil texture and the contents of C-org, N-t, and P-t indicating that in the temperate forests the taxonomic and functional composition of soil microbial communities are shaped by both the soil properties and the vegetation. The functional diversity of soil microbial communities was not related to plant diversity indicating that in temperate forests the number of plant species has little effect on the ability of soil microorganisms to degrade different organic compounds.