The effect of arbuscular mycorrhizal fungi Rhizophagus intraradices and soil microbial community on a model plant community in a post-mining soil

Abstract

The aim of this study was to assess the effect of arbuscular mycorrhizal fungi Rhizophagus intraradices and soil microbial groups and their interactions on a simple plant community in a microcosm experiment. The experiment was performed with two grass species (Poa compressa, Festuca rubra) and two herb species (Centaurea jacea, Lotus corniculatus) which are characteristic of intermediate succession stages in post-mining sites. Three months before the start of the experiment, bacteria, saprophytic fungi, protists, and their combined treatments were inoculated into the soil. At the start of the experiment, half of the pots were inoculated with mycorrhiza. After 60 days, plants were harvested and shoot and root biomass and microbial respiration and biomass were assessed. Above- and belowground plant biomass was significantly lower in the treatments with mycorrhiza. The effect was significant for aboveground biomass of grasses, especially that of Poa compressa, and for grass/herb ratio but not for herbs. Microbial respiration was also lower with mycorrhiza. Among microbial community treatments, saprophytic fungi showed significant effects on plant growth. The results showed the importance of mycorrhizal fungi on plant biomass and its interaction with different plant species and microbial groups which would be useful when extrapolating these results to a natural environment.