The introduction of non-native plant species coupled with disturbance can dramatically alter community composition, diversity, and ecosystem
processes. Such changes can act as long-term barriers to system recovery even after removal of the non-native plants. We hypothesized
that persistent alterations in soil microbial communities may act as one mechanism preventing system recovery. To test this hypothesis, we
used experimental restoration of Florida scrub habitat that had been disturbed (‘disturbed scrub’) or significantly degraded (‘converted
pasture’) by the introduction of non-native grasses and grazing management. The restoration treatments consisted of non-native grass
removal and reintroduction of the native microbial community, with outcomes compared to a set of undisturbed native reference sites. We
focused on soil fungi in this nutrient-poor ecosystem because of their key roles in decomposition and soil nutrient cycling. Specifically, we
examined the resistance of soil fungal communities to disturbance and non-native species, tracked their resilience over time, and tested
whether fungal community could be increased via inoculation from native sites. Soil fungal abundance and community composition were
characterized with microscopy and ITS rDNA. Other soil properties were also examined as potential covariates, including soil moisture,
carbon, nitrogen, and microbial biomass.
Results/Conclusions
Across all sites, we identified fungi from more than 100 fungal genera. The majority of fungal taxa belonged to the Ascomycota (~72%)
and Basidiomycota (~27%), with fewer members of the Glomeromycota (~5%) and basal fungal lineages (~8%). Fungal hyphal networks were 2-2.5x greater in the disturbed scrub and converted pasture sites compared to native scrub. The size of the fungal network was also
correlated with some soil conditions, increasing in drier sites and those with a higher microbial biomass C:N ratio. Fungal networks were
only slightly reduced by invasive plant removals, suggesting these were largely saprophytic rather than mycorrhizal networks. Based on
preliminary analyses, fungal community composition was similarly affected by former land use and restoration treatments, but other
factors may play a stronger role. If fungal community composition and abundance prove to be primary drivers of soil processes in Florida
scrub as they are in other ecosystems, then successful restoration may require directly targeting these microbial communities. Understanding
the role of soil microbes in ecosystem resilience to disturbance and invasive species will elucidate mechanisms underlying ecosystem
functioning and potentially broaden our toolkit for management and restoration.