Arbuscular mycorrhizal fungi associated with alpine meadow multifunctionality in a warmer climate with variable precipitation

In addition to supporting plant productivity and nutrient cycling, arbuscular mycorrhizal (AM) fungi contribute to multiple functions within terrestrial ecosystems. However, as ecosystems face increasing temperatures and changes in precipitation, these factors may affect how AM fungi interact with ecosystem multifunctionality. Here, we investigated how warming and precipitation changes affected plant and AM fungal communities, as well as ecosystem multifunctionality in a field experiment in an alpine meadow on the eastern Tibetan Plateau that had warming and precipitation change (40% increase or decrease) manipulated experimentally from 2017. Less AM fungal diversity and evenness resulted from warming combined with increased precipitation. Increased precipitation had a significant negative indirect effect on ecosystem multifunctionality through its direct effect on grass biomass and then on AM fungal community composition. Both warming and precipitation had a positive indirect effect on ecosystem multifunctionality through their direct negative effect on AM fungal diversity and positive effect on soil moisture. We conclude that alterations in the species diversity and community composition of AM fungi due to warming and precipitation change mediate ecosystem multifunctionality. Warmer, humid conditions contribute to higher ecosystem multifunctionality, driven by climate change-induced interactions between plants and AM fungi.