Positive and negative feedbacks between plant communities and soil communities are important drivers of plant community diversity and may be important in assisting plant communities in transitions between successional stages. This idea has been tested in the context of prairie restoration, where conventionally farmed land is re-seeded with prairie plant species. Post-seeding, prairie restorations follow a predictable successional sequence of plant establishment, but rarely recover the full suite of species characteristic of a late successional prairie remnant. We have been investigating how plant/soil feedbacks can be used to improve the representation of plant species characteristic of prairie remnants in restorations. The first investigations used whole soil collected from post-conventionally farmed fields and prairie remnants to compare whether establishment of late successional prairie plants improved with prairie soil. Subsequent investigations focused on using prairie-remnant derived arbuscular mycorrhizal fungi (AMF) to test specific prairie plant/prairie fungal interactions. The most recent investigations have paired specific prairie-derived AMF with prairie plants representing the spectrum of successional stages to evaluate whether plant successional stage is a predictor for AMF responsiveness and if there are plant species specific responses to different AMF species.
Results/Conclusions
The earliest investigations demonstrated that plant species characteristic of prairie mid-late successional stages survived and grew best in prairie whole soil. When a suite of prairie-remnant derived arbuscular mycorrhizal fungi were planted with mid-late successional plants, the same pattern emerged, suggesting that AMF may be responsible for driving the whole soil response seen in prior experiments. When plant species representing early, mid, and late successional stages within a family were tested with individual species of AMF, the late successional species were more responsive to AMF and were more sensitive to AMF species identity than the early species, suggesting that responsiveness to AMF may be a shared late successional plant life history trait. Taken together, these results indicate that in the prairie system, there is a strong link between AMF derived from late successional prairie remnants and the success of late successional prairie plants. Without the restoration of the AMF community, many late successional prairie plant species fail to establish or persist, resulting in a prairie restoration with a less diverse suite of established species.