Fungal populations in podzolic soil experimentally acidified to simulate acid rain.

The effect of experimental acidification on the soil microfungal community was studied in the humus layer of a coniferous forest in northern Sweden. The study was made 4 years after the last application of sulfuric acid. Fungal species composition was altered by treatments of 100 and 150 kg sulfuric acid ha(-1) each year for 6 years, yet no differences were found between the control treatment and an application of 50 kg ha(-1). The abundance ofPenicillium spinulosum andOidiodendron cf.echinulatum II increased with increasing rates of acid application, whereas only small changes were found for other isolated fungal taxa. Soil respiration rate and fluorescein diacetate (FDA)-active fungal biomass were significantly different from the control treatment at all 3 levels of acidification.