Arbuscular Mycorrhizal Fungi Taxa Show Variable Patterns of Micro-Scale Dispersal in Prairie Restorations

Abstract

Human land use disturbance is a major contributor to the loss of natural plant communities, and this is particularly true in areas used for agriculture, such as the Midwestern tallgrass prairies of the United States. Previous work has shown that arbuscular mycorrhizal fungi (AMF) additions can increase native plant survival and success in plant community restorations, but the dispersal of AMF in these systems is poorly understood. In this study, we examined the dispersal of AMF taxa inoculated into four tallgrass prairie restorations. At each site, we inoculated native plant species with greenhouse-cultured native AMF taxa or whole soil collected from a nearby unplowed prairie. We monitored AMF dispersal, AMF biomass, plant growth, and plant community composition, at different distances from inoculation. In two sites, we assessed the role of plant hosts in dispersal, by placing known AMF hosts in a “bridge” and “island” pattern on either side of the inoculation points. We found that AMF taxa differ in their dispersal ability, with some taxa spreading to 2-m in the first year and others remaining closer to the inoculation point. We also found evidence that AMF spread altered non-inoculated neighboring plant growth and community composition in certain sites. These results represent the most comprehensive attempt to date to evaluate AMF spread.

Crop Productivity Boosters: Native Mycorrhizal Fungi from an Old-Growth Grassland Benefits Tomato (Solanum lycopersicum) and Pepper (Capsicum annuum) Varieties in Organically Farmed Soils

“…One past study found that the effects of inoculation persisted for two years [ 16 ] for an annual crop. Another study found that AM fungal inoculation can spread meters per year across a field [ 36 ]. However, research on both the persistence and spread of inoculation in organic agriculture is lacking.…”

Native arbuscular mycorrhizal fungi promote native grassland diversity and suppress weeds 4 years following inoculation

“…Positive plant‐AM fungal feedback is known to occur in prairies and other grasslands (Kardol et al 2007) and ponderosa pine stands (Korb et al 2004). The two sides of positive feedback, that is, amplification of native plant success with native AM fungi inoculation, along with the inhibition of natives in the absence of native AM fungi, could explain the persistence of beneficial inoculation even though native AM fungi have been shown to propagate and spread 1–2 m per year from their place of introduction (Middleton et al 2015; Tipton et al 2022). We observed particularly strong responses to inoculation from native legumes, which is consistent with previous observations of strong responses of late successional legumes to AM fungi (Koziol & Bever 2015).…”

“…More generally, it is not known how long the benefits of AM fungi inoculation might persist. On the one hand, benefits of reintroduction of native AM fungi may be expected to diminish overtime because beneficial AM fungi are expected to eventually disperse and colonize restoration sites (Middleton et al 2015; Tipton et al 2022). Alternatively, initial inoculation of strongly responsive hosts with beneficial native AM fungi may generate positive feedbacks that could alter the long‐term trajectory of a restoration, thereby resulting in persistent benefits.…”

“…First growing season results indicated that native mycorrhizal amendments may help meet restoration goals, including improved native plant richness, abundance, and diversity (Koziol et al 2020). However, the persistence of these differences might not be expected given that plants culture and propagate mycorrhizal fungi and that native AM fungi can spread 1–2 m/year (Middleton et al 2015; Tipton et al 2022) thereby potentially crossing the 3‐m mowed isles between inoculation treatments and eroding treatment differences over time. We therefore test the hypothesis that native mycorrhizal amendments will continue to improve native plant richness, abundance, and diversity 4 years after application.…”

Arbuscular mycorrhizal fungi travel the world with underground crop harvest

“…When new AM fungal strains are introduced into existing soil microbial communities, e.g. via biofertilizers based on AM fungal inoculum, they can successfully establish in agricultural and natural systems (Pellegrino et al, 2012;Tipton et al, 2022). However, invasive AM fungal strains can also pose a threat to biodiversity and functioning of natural ecosystems (Hart et al, 2018).…”