Changes in soil bacterial communities in response to the fairy ring fungus Agaricus gennadii in the temperate steppes of China

Abstract

Fairy rings (FRs), mysterious circles of fungal fruiting bodies that occur in open grassy areas, have long been reported, but scientists know little about their effects on the physiochemical properties of soil and the associated bacterial communities. We investigated three concentric zones of Agaricus gennadii FRs in June, August and October 2016 in a temperate steppe of China outside of rings (OUT), within rings (IN) and adjacent to fruiting bodies (ON) to determine the effects of FR fungus on soil properties and bacterial community structure. Significantly higher aboveground biomass was only observed in the ON zone because of an increase in available soil P (P < 0.05). Soil total N, total P and inorganic N were lower in the ON and IN zones than in the OUT zone. The bacterial Shannon and Chao 1 indices were significantly higher in samples associated with the rings in August and October (P < 0.05). At the family level, only the abundance of Microbacteriaceae was significantly higher in the ON zone than in the OUT zone during the three-month study period (P < 0.05), indicating that species of the Microbacteriaceae are associated with Agaricus gennadii FRs. Moreover, the changes of soil pH and soil available P caused by FRs were found to be better indicators of changes in soil bacterial communities than total N, total P and inorganic N in soil.