Ectomycorrhizal fungi (EMF) are a specific group of mycorrhizal fungi that form associations with the fine roots of trees and other woody perennials. EMF are especially dominant in temperate and boreal ecosystems where they have influential roles in plant community composition and soil nutrient cycles. What separates EMF from the other mycorrhizal fungal groups are their extreme diversity (over 80 lineages and 20,000+ species!), and the unique structures they form in- and outside the root. Inside the root, EMF form a structure called the Hartig net where nutrient exchange occurs. Outside, a sock-like mantle is formed on the root epidermis, and hyphal structures in the form of diffuse strands and/or cord-like rhizomorphs extend into the soil. Using these functionally diverse structures, EMF not only aid in host nutrient and water uptake, but also maintain fungal communities of >50 species on a single tree. Further, EMF help to establish seedlings, aid in root pathogen resistance, and increase host tolerance to abiotic stressors like drought and heat. Now that you've been introduced to EMF, I'm sure you're dying to dig up more! In that case, you can check out this post on mycorrhizal signaling, or this one on mycology and art. Moreover, you can look below for information on Root Lab projects, most of which involve your new fungal favs. 

EMF community Phenology

Flowers bloom, fruits ripen, and leaves fall, but how do the seasons impact life belowground? The seasonality of EMF is relatively unknown because researchers tend to sample the community only once during the year. To address this mystery, we are sequencing soil and fine-root samples from our forestry plots at multiple time-points throughout the year and tracking how the EMF community shifts in relation to seasonal changes in factors like soil moisture, temperature, and host-tree phenology.

Seasonal EMF production

Speaking of fruits ripening, many of us have come across the random mushroom, or fungal “fruit body,” popping up after a rain event. The aboveground nature of mushrooms allows us to observe their typical production periods, but the production patterns of belowground structures like hyphae and rhizomorphs remain unknown. To begin answering this question, we are analyzing belowground images of EMF structures using long-term datasets (monthly images from 2019 - ongoing) from our forestry plots to asses the environmental and host effects on seasonal EMF production. 

EMF traits

For a half-century now, ecologists have used trait-based approaches to understand community composition and ecosystem functions. However, trait work on fungi lags behind plant and animal research. To even the playing field, we're measuring a suite of anatomical and chemical traits from samples of EMF within our plots. Based on our other phenology-based studies, it may be of no surprise that we're looking to answer questions concerning the effects of season and host on EMF trait values. 

fine-Root responses to Waterlogging

The root systems of urban trees often have to withstand periods of full submergence, or waterlogging. Waterlogging is a common occurrence in our cities because of things like soil compaction and poor site design. To test how fine roots respond to waterlogging stress, and why some species are more tolerant to waterlogging, we waterlogged four common urban tree species to and took measurements of photosynthetic performance, fine-root death, and tissue stress. Check out this poster to see our findings!