Leś. Pr. Bad., 2005, 4: 7–18.
Oznaczanie udziału grzybów i bakterii w biomasie drobnoustrojów
gleb leśnych
Estimation of fungal and bacterial contributions to microbial biomass
in forest soils
Józef Zwoliński
Instytut Badawczy Leśnictwa, Zakład Gospodarki Leśnej Rejonów
Przemysłowych, ul. Św. Huberta 35, 40-952 Katowice, Poland, e-mail:
zwolinsj@ibles.waw.pl
Abstract. The method of selective inhibition of substrate-induced respiration (SIR) by antibiotics was adapted to measure fungal and bacterial contribution to microbial biomass in forest soils. To optimize the concentration of fungicide cycloheximide and bactericide streptomycin, dose-response experiments with pine forest soils were conducted. The results of SIR inhibition indicated that concentration of 90 mg cycloheximide and 25 mg streptomycin×g-1 soil for organic horizons (Ofh), and 15 mg cyclohexamide and 10 mg streptomycin×g-1 soil for mineral horizons (AE) caused maximum selective inhibition of SIR. The fungal to bacterial ratio in pine forest soils was found to be above 2.0 and about 1.5 in organic and mineral horizons, respectively.
Key words: pine forests, substrate-induced respiration (SIR), soil microbial biomass, selective inhibition of SIR, fungal: bacterial ratio.

