Study Finds Fungal-Rich Soil May Improve Green Roofs
Sourced from Dartmouth College
Green roofs have become increasingly popular thanks to their benefits related to climate adaptation, mitigation, and urban biodiversity management.
These vegetated surfaces on the rooftops of buildings absorb excess stormwater, reduce energy use by insulating buildings, and cool neighborhoods, tempering urban heat islands while also creating urban habitats for plants, pollinators, and wildlife.
But, in the U.S., green roofs are typically planted with non-native plants in sterile soils, and their effectiveness declines over time.
A Dartmouth-led research team set out to determine if managing green roof soil microbes could boost healthy urban soil development, a methodology that could be applied to support climate resilience in cities.
The team created an experimental green roof in Chicago to test how enhancing soil with native prairie microbes would change the soil microbial community over time. They were particularly interested in tracking the presence of beneficial mycorrhizal fungi.
Mycorrhizal fungi are well-known to live in roots and support plants in a symbiotic underground relationship, delivering nutrients and water to them in exchange for plant sugars. Mycorrhizal fungi could be particularly helpful to plants in green roofs that have to endure high temperatures, intense sun, and periodic flooding.
The researchers added soil rich with native mycorrhizal fungi obtained from a local restored prairie, referred to as “inoculum,” to the experimental green roof’s soil. They planted inoculated and untreated soil with native prairie plants and green roof succulents. Over two years, the team tracked changes in the mycorrhizal fungal community of the green roof. They also compared the fungal species identified on the green roof to those present in the inoculum and in the air.
From the Living Architecture Monitor
