Fungal biomass and diversity in sediments and on leaf litter in heavy metal contaminated waters of Central Germany

Abstract

Ergosterol, as indicator of fungal biomass, was measured in the CPOM (coarse particulate organic matter; ≥ 5 mm) and FPM (fine particulate matter; ≤ 1 mm) sediment fractions of 11 heavy metal contaminated streams, springs and ponds in Central Germany. At 7 sites, ergosterol concentrations of FPM were below the detection limit. At the remaining sites, they corresponded to a fungal biomass of 0.03 - 0.06 % of FPM. Corresponding values for the CPOM fractions were 0.1 - 1.3 %. Both fractions produced conidia of aquatic hyphomycetes, either directly upon aeration (CPOM) or indirectly by colonization, followed by spore release, of sterile target disks. Between 0.05 and 63 conidia per mg substrate were released from naturally deposited leaves upon aeration and from Alms glutinosa leaves that had been exposed for four weeks, recovered and aerated. Canonical analysis of principal coordinates, based on presence/absence of fungal species, did not reveal significant correlations with site or substrate. The survival of an impoverished fungal community in and on the sediments of water bodies under severe anthopogenic stress suggests the maintenance of at least basic ecological functions and raises the possibility of recovery upon removal of the stress.