Fungal to bacterial biomass ratio in the forests soil profile

The carbon content in microbial biomass (C-mic-MB) was determined in various horizons of the soil profile (sod-podzo, gray, podzol, and rzhavozem) of various forests (oak, spruce archangel, spruce moss, aspen, spruce broadleaf) in the southern taiga of European Russia (Moscow and Kaluga regions) by the substrate-induced respiration (SIR) and direct microscopy (DM) methods. The fungi-to-bacteria ratio was measured by the selective inhibition technique and DM. A quantitative differentiation of the fungal mycelium was suggested. The C-mic-DM / C-mic-SIR in various horizons of the soil profile was about 98%. The fungal contribution to MB was 52-74% and 92-99% according to the SIR and DM methods, respectively. The microbial parameters were associated with the CO2 and N2O production by the soils. The contradictory data about the fungal portion in the MB of soils of various ecosystems were discussed.