The interaction between the total fungal community and individual plant species of the prairie environment remains poorly understood due to the complexity of the environment and the diverse nature of soil microbial communities. In diversified grasslands, it is unknown how individual plant species and the plant community shape fungal community structure. This is particularly challenging within a prairie ecosystem where the complex rhizosphere environment can be difficult to disentangle from the individual plant species selection on the fungal community. We used a multi-scale approach to assess how plant species, plant communities, and grassland management selected soil fungal communities. At two different restored Iowan prairies, with and without nitrogen fertilization, we examined the fungal community diversity and composition to determine if individual species within a complex plant community are selectors for the fungal community structure.
Results/Conclusions
We found plant community composition varied significantly between fertilized and native prairie. The absence of legumes in the fertilized prairie was notable, and proved to be highly influential on the fungal community. On the ecosystem level, we detected no difference in fungal community structure. Instead we found that some plant functional groups and individual plant species had significant impacts on the fungal community diversity. Of the 13 plant functional groups examined only legumes impacted fungal community structure. Fungal community richness decreased, resulting in the loss of 22 fungal families in the presence of legumes. This response was largely attributed to the dominant legume, Dalea purpurea. We observed an ecosystem by plant species interaction on fungal richness for two forbs, Rudbeckia hirta and Silphium lactinatum. The impact of Dalea purpurea and the two forb species on fungal community diversity was disproportionate to their abundance, 3.16%, of the total plant community. Which supports the idea of function over quantity in determining species ecological value. This study also demonstrates that while nitrogen enrichment may not directly affect fungal community structure in prairie ecosystems, it may cause an indirect effect by changing the plant community structure and potential function.