Microarthropods as regulators of the communities of microscopic fungi and biological activity in the litter of a mixed forest

Abstract

The role of microarthropods as probable regulators of the communities of microscopic fungi and the activity of respiration and nitrogen fixation in the falloff of a mixed forest was studied in laboratory experiments. Changes in the composition of fungi were already seen two weeks after introduction of microarthropods to the falloff. The diversity of micromycetes and uniformity of species by relative abundance was higher in their presence. This was the result of the more rapid (than without microarthropods) decrease in the abundance of dominating fungi, which were represented in the fresh fall by dark-colored species. It was demonstrated in the experiments with pure cultures of fungi that Folsomia candida, a representative of the complex of microarthropods, preferred to consume the most abundant species in the falloff and litter. The microarthropods caused an increase in the intensity of respiration (1–3 days) and nitrogen fixation (1 month) after their introduction to the falloff. The trend toward a higher intensity of these processes remained during the next four months of incubation of the falloff with the animals.