Fungal endophyte infection increases tall fescue's survival, growth, and flowering in a reconstructed prairie

Grasslands in North America are increasingly threatened by land conversion and ecological degradation, prompting restoration efforts to increase native plant species diversity and improve wildlife habitat. A major challenge is the removal and management of nonnative invasive species such as tall fescue (Schedonorus arundinaceus), which has a symbiotic association with a fungal endophyte (Epichloë coenophiala) that modifies its ecological interactions. Using transplanted clumps of the cultivar Kentucky-31, we tested the effects of endophyte infection on tall fescue's survival and performance (tiller production, flowering, and basal area) for 5 years in a central Kentucky reconstructed prairie. We predicted that endophyte infected (E+) clumps would have increased performance compared to endophyte-free (E−) clumps. Overall, E+ clumps had greater survival, tiller production, flowering tiller production, and basal area, but not reproductive effort (proportion of tillers flowering) as compared to E− clumps. However, survival and trends in tiller number and basal area over the 5-year period suggested experimental tall fescue populations were in decline in the reconstructed prairie, although the E− population declined more rapidly. Our study provides evidence that endophyte infection improved tall fescue's growth and survival in a postreconstruction plant community, at least in the early years following reconstruction, and may increase the invasive potential of this nonnative species in prairie restorations.