Above-Below Ground Coupling

The diversity and composition of aboveground tree communities are not independent of what lives belowground. Mycorrhizal fungi — symbiotic partners that connect tree roots to the soil — play a central role in nutrient cycling, carbon storage, and forest dynamics. Yet the spatial patterns of mycorrhizal associations across landscapes, and their coupling with plant diversity, have been poorly understood at macroscales.

Our lab uses continental-scale forest inventory data combined with DNA sequencing of soil samples to map mycorrhizal communities and examine how they co-vary with tree communities across the contiguous United States. We have shown that the dominance of arbuscular mycorrhizal (AM) versus ectomycorrhizal (EM) tree associations is driven primarily by climate, and that anthropogenic influences — particularly nitrogen deposition and fire suppression — have shifted mycorrhizal dominance over the past three decades. We are currently building the first national-scale mycorrhizal diversity database from DNA sequencing of Forest Inventory and Analysis (FIA) soil samples, an effort that will enable new understanding of plant–fungal relationships over time.

This image depicts the EM to AM tree dominance of ecoregions around the united states. The AM dominant areas are depicted in orange while the EM dominant areas are represented in blue. The Ecoregions shown are the Marine, Mediterranean, Temperate desert, Temperate steppe, Tropical/subtropical desert, Tropical/subtropical steppe, Prairie, Warm continental, Hot continental, Subtropical, and Savannah.

Active Grants:

  • Revealing spatial and temporal patterns of mycorrhizal distribution in forest ecosystems across the US — USDA Forest Service, 2023–2028
  • Elucidating plant and mycorrhizal fungal relationships and consequences across space and time — National Science Foundation, 2021–2024

Representative Publications — Above–Below Ground Coupling

  1. Jo, I., Fei, S., Oswalt, C.M., Domke, G.M., & Phillips, R.P. (2019). Shifts in dominant tree mycorrhizal associations in response to anthropogenic impacts. Science Advances, 5(4), eaav6358. https://doi.org/10.1126/sciadv.aav6358
  2. Mushinski, R.M., Phillips, R.P., Payne, Z.C., Abney, R.B., Jo, I., Fei, S., Pusede, S.E., White, J.R., Rusch, D.B., & Raff, J.D. (2019). Microbial mechanisms and ecosystem flux estimation for aerobic NOy emissions from deciduous forest soils. PNAS, 116(6), 2138–2145. https://doi.org/10.1073/pnas.1814632116
  3. Fei, S., Kivlin, S.N., Domke, G.M., Jo, I., LaRue, E.A., & Phillips, R.P. (2022). Coupling of plant and mycorrhizal fungal diversity: its occurrence, relevance, and possible implications under global change. New Phytologist, 234(6), 1960–1966. https://doi.org/10.1111/nph.17954
  4. Jo, I., Potter, K.M., Domke, G.M., & Fei, S. (2018). Dominant forest tree mycorrhizal type mediates understory plant invasions. Ecology Letters, 21(2), 217–224. https://doi.org/10.1111/ele.12884
  5. Luo, S., Phillips, R.P., Jo, I., Fei, S., Liang, J., Schmid, B., & Eisenhauer, N. (2023). Higher productivity in forests with mixed mycorrhizal strategies. Nature Communications, 14, 1377. https://doi.org/10.1038/s41467-023-36888-0