Fungal and bacterial contributions to the decomposition of Cladium and Typha leaves in nutrient enriched and nutrient poor areas of the Everglades, with a note on ergosterol concentrations in Everglades soils

Fungal biomass was detected in peat soils from throughout the Everglades ba sed on the presence of ergosterol. Ergosterol concentrations in soils were not detectably affected by the dominant plant, Cladium jamaicense or Typha domingensis, or phosphorus content of soils. In situ decomposition of decay ing leaves, measured by respiration, was high (maximum 484 mu l, h(-1) g(-1 ) dry biomass). Approximately 30% of respiration was by bacteria and the re st was by fungi and other eukaryotes. Respiration rates were essentially th e same for decomposing leaves of both plant species, with higher rates earl y in the decomposition process. Respiration rates were relatively unaffecte d by the nutrient status of the site, except for eukaryotic respiration on Cladium, which was usually higher at a high nutrient site. Ergosterol conce ntration increased in decaying leaves through time and was unrelated to the nutrient level except for Cladium, where ii was higher at the high nutrien t site. Eukaryotic respiration was not correlated with ergosterol concentra tion in decomposing leaves of Typha, but was positively correlated with erg osterol for Cladium.