Disturbance tolerance of arbuscular mycorrhizal fungi: trait-based characterization along a disturbance gradient in a coastal dune ecosystem

Abstract

Abstract Purpose Arbuscular mycorrhizal fungi that regenerate rapidly after disturbance play a significant role in resilience of vegetation after disturbance. We experimentally characterized disturbance-tolerance traits of the fungi that inhabit a coastal dune ecosystem. Methods Root-zone soils, including root fragments, were collected from the seaward and landward slopes that differ in disturbance severity. The native grass Miscanthus sinensis (donor plants) were grown in the soils for two months, and from a half of the plants, disturbance-tolerant fungi that regenerate from spores and extraradical hyphae (soil propagule-mediated regenerators, SP) and those that regenerate from the colonized roots (root-direct regenerators, RD) were trapped separately with new seedlings (assessment plants). The other half of the donor plants were further grown for four months together with assessment plants, during which the fungi trapped by the assessment plants were categorized as disturbance-sensitive slow regenerators (SL). DNA was extracted from the assessment plants, and fungal taxa were identified based on LSU rDNA sequences. Results All fungi occurred in the seaward soil samples showed the SP and/or RD traits, whereas those occurred in the landward samples showed not only SP and/or RD traits but also SL traits. The seaward fungal communities were nested within the landward communities, implying that they were selected from the landward communities. Conclusion These observations suggest that rapid regeneration from soil-borne propagules and colonized roots are key traits of the fungi for survival in dune ecosystems, providing a new insight into the life-history strategies of AM fungi in frequently and severely disturbed ecosystems.