Small-scale distribution of extracellular enzymes, fungal, and bacterial biomass in Quercus petraea forest topsoil

Abstract

The small-scale distribution of activities of extracellular laccase, Mn-peroxidase, endoglucanase, cellobiohydrolase, β-glucosidase, endoxylanase, β-xylosidase, chitinase, and acid phosphatase were studied in the litter (L) and organic (H) horizons of Quercus petraea forest soil and related to the distribution of microbial biomass. Geostatistical analysis showed that the spatial autocorrelation of the enzyme activities and soil microbial biomass measured as phospholipid fatty acids (PLFA) and ergosterol content occurred at similar scales, typically in the range of tens of centimeters. The size of the spatial structures differed between the L and H horizons; for most of the studied enzymatic processes, litter exhibited a higher spatial variability (smaller autocorrelation distances). The distribution of several enzymes, including laccase, Mn-peroxidase, and some hydrolases, reflected the distribution of fungal biomass. Polysaccharide hydrolases exhibited similar spatial distribution patterns in the L horizon, and their activity coincided with a high fungal/bacterial biomass ratio.