Recovery and resistance of soil fungal communities in ecological and conventional grasslands under altered rain regimes

Climate extremes, including droughts and floods cause major fluctuations in the functioning of ecosystems. With this research we assess the role of soil fungal communities in the resistance and the recovery of conventional and organic managed grasslands. Intact monoliths were extracted from conventional and organic grasslands in three Europen countries and exposed to three rain regimes (dry, wet and intermittent wet/dry) compared to a normal regime. Total soil fungal communities and arbuscular mycorrhizal fungal communities were characterized across the experiment using high throughput sequencing (Illumina MiSeq). Subsequently, the resistance and recovery of total soil fungal communities, soil fungal pathogens, saprotrophs and symbionts (mycorrhizal fungi) to the rain regimes were calculated. Organic and conventional managed grasslands had different soil fungal communities. Ecological management enhanced the recovery of the soil fungal communities to altered rain regimes. However, independently to the grassland management, soil fungal communities were less resistant to the intermittent wet/dry regime than to the dry or wet rain regimes. Changes on the recovery and the resilience of the overall fungal community related to changes on the saprotrophic fungal community. Whereas, the resistance and the recovery of the arbuscular mycorrhizal fungal communities was not affected by rain regimes or management. We conclude that organic management of grasslands is a better option than conventional management to increase the recovery of soil fungal ommunities to climate change. Among soil fungal functional groups, saprotrophs are main drivers of resistance and recovery patterns.