Effects of experimental acidification on nematode populations in soil cultures

The effect of artificial acidification on soil nematodes were determined in a laboratory experiment. Soil samples were sprayed with diluted sulfuric, nitric or oxalic acid of pH 2.0, 1.5 and 1.0 and incubated for 6 weeks.The number of bacteria decreased after acid treatment. The response to all tested acids was similar.Acidification caused negative effects on nematode species number and population density. Additionally, the dominance structure changed. A shift in favour to root and fungal feeders was observed along with increasing acid concentrations. The effects of oxalic acid were of short duration.Among the root and fungal feeders the species of the genus Aphelenchoides dominated after acidification. Comparing two bacterial feeders, the eudominant species Wilsonema schuurmansstekhoveni (DE CONICK, 1931) and the rare species Acrobeloides buetschlii (DE MAN, 1884), the latter gained in importance after the acid treatment.