Can mycorrhizal fungi alleviate plant community instability caused by increased precipitation in arid ecosystems?

Background and aims: Plant community stability is threatened by anthropogenic climate changes such as increased precipitation. Arbuscular mycorrhizal (AM) fungi have been shown to drive the resistance of ecosystems against climate changes to provide stable ecosystem functions. However, how AMF affects plant community stability under climate change is still not sufficiently clear in Central Asia. Methods: A comprehensive study was conducted with increased precipitation and suppression of AMF in mycorrhizal and non-mycorrhizal plant communities, respectively. Changes in plant community composition and aboveground biomass were measured, and the temporal stability of plant community was calculated. Results: Mycorrhizal plant community responded more sensitively to the increased precipitation and suppression of AMF than non-mycorrhizal plant community. Species synchrony and population variability were only significantly changed by increased precipitation in the mycorrhizal plant community. The stability of dominant and mycorrhizal plants were positively related to community temporal stability of both plant communities. While contrasted with the positive effects of increased precipitation on community temporal stability, increased precipitation reduced community temporal stability by increasing temporal variations of plant biomass in the mycorrhizal plant community, and by decreasing plant diversity in the non-mycorrhizal plant community. However, AMF buffer the decreases in community stability by increasing plant community biomass under increasing precipitation. Conclusion: Our findings highlight ongoing increases in precipitation potentially weaken the temporal stability of ephemeral plant communities in the desert ecosystem stability; however, AMF can alleviate these negative effects through increasing community biomass, especially in the plant community dominated by mycorrhizal species. [ABSTRACT FROM AUTHOR]