The spatial variation in soil moisture was found to affect the total
microbial biomass (Stoyan et al., 2000; Gömöryová et al., 2006),
measured as basal respiration. In a Quercus rubra forest soil, bacterial
counts were affected by moisture while fungal hyphal length
was not (Morris, 1999). In this work, we used PLFA and ergosterol
contents as more accurate estimators of microbial biomass content.
Our results show that microbial biomass increases with soil moisture,
although the effect varies among seasons and is specific for
the L and H horizons. The differences in soil moisture could explain
up to 60% of the total variability and were thus the most important
factor affecting the small-scale distribution of microbial biomass.
The responses of fungi and bacteria are not similar. While bacterial
biomass responded to soil moisture more strongly in theHhorizon,
fungal biomass showed better correlation in the L horizon. This is