What if there was a product with magical properties that could reduce the risk of wildfires and help restore forests after a wildfire? But wait–there’s more. What if this product could be used to improve depleted agricultural land and make it productive again? What if this product could be scaled to deal with large landscapes, reduce fossil fuel use, is local to the environment and can combat climate change?

Mycologist Zach Hedstrom of Boulder Mushroom thinks that he has found such a product in the fungal threads and filaments of mushrooms. Hedstrom and his company Boulder Mushrooms have partnered with the Boulder Watershed Collective and Grama Grass and Livestock on a pilot project to spray wood chips with a solution of mushroom mycelium to speed up the decomposition of wood fibers from mitigated trees. They have been awarded a $100,000 grant from the City of Boulder’s Department of Climate Initiatives and Boulder County’s Climate Innovation Fund, which was established in 2022.

On Friday, October 13, 2023, the Boulder County Office of Sustainability, Climate Action and Resilience (BCOSCAR) held an in-person demonstration of this innovative project at the Sacred Mountain Ashram in Gold Hill. Commissioner Ashley Stolzman in her introductory remarks said that it is an exciting concept, with the kinds of benefits the sustainability group and Climate Innovation Fund are looking to invest in.

Maya MacHamer from the Boulder Watershed Collective welcomed the group on behalf of the Sacred Mountain Ashram and residents of Gold Hill. She acknowledged their connection to the land and innovative wildfire mitigation work. She said the momentum was encouraging and commended the Gold Hill community for their dedication in creating wildfire-resilient landscapes.

Christian Herrmann from BCOSCAR spoke about the mitigation project at the Ashram. About 18 acres were cut in 2022 and 2023. The mitigation work was done by the Four-mile Fire Mitigation Crew and funded by Ecocycle and the Boulder Valley and Longmont Conservation Districts. Instead of building slash piles, the mitigated wood was chipped and spread across the landscape. A solution of mushroom mycelium was sprayed on the chips to speed up the rate of decomposition.

Hedstrom was the featured speaker at the event and gave a brief overview of the concepts involved in treating biomass material resulting from wildfire mitigation projects with a nature-based climate solution. His research indicates that wood chips treated with mycelium can decompose into healthy soil in 3-5 years, compared to 30 years for untreated chips.

Mycelium is the root system of a mushroom. The parts of a mushroom that stick out above the ground are called fruiting bodies. The mycelium are threads or filaments that form the vegetative body of the mushroom. It can digest woody biomass to produce nutrient-rich soil. Mycelium decomposes woody biomass using enzymes the way the secretions of worms can decompose rock and turn it into soil.

Hedstrom referred to the mushroom method as another tool in the wildfire mitigation toolbox of strategies to deal with the excess biomass that is generated from these mitigation projects. He contrasted the mushroom method with other ways to deal with excess biomass, like slash piles or trucking it away. The problem with slash piles is that they tend to burn too hot and tend to leave blisters on the ground that are nutrient-deficient. The Biochar method produces a nutrient rich by-product, but it requires a lot of energy to do the pyrolysis, burning biomass without oxygen. In contrast, the mushroom method is considered “cold fire” because the energy to consume the woody biomass comes from living organisms that are native to the ecosystem. The end result with the mushroom method is ground that is nutrient-rich and holds moisture and controls topsoil erosion.

Trucking the excess biomass requires additional fossil fuel to dispose of it at offsite locations. The mushroom method relies on an in-place, nature-based solution to deal with the excess biomass in a way that is ecologically sound, safe, and helps to support soil health and moisture retention in the watershed.

Mycelium can be combined with mulch after a wildfire to help with stabilizing the topsoil and prevent mudslides and slope erosion. When the mycelium fibers grow through the mulch, they create nets that glue the mulch layers together and are capable of holding soil together and retain moisture. It acts as a big sponge on the ground. Mulch that has been sprayed with a mycelium solution can be dropped on steep post-fire landscapes for slope stabilization.

The other component of the grant was to send treated or inoculated wood chips to the plains to revitalize exhausted farmland. The Grama Grass and Livestock company is spreading inoculated chips on a farm in the Longmont area to promote healthy soil and regenerative farming.

After his talk, Hedstrom led the group to the mitigation site to look at how the mycelium was working after 16 months. He exposed areas that had been treated and dug up the soil to show its richness. He was asked if there were any ecological dangers of using mycelium. Hedstrom stressed that they use native mushrooms for their starter spores, so it was a local organism that was already part of the ecosystem. It takes about ten pounds of mycelium product to inoculate an acre of land. The process can be scaled up simply by increasing the number of vats that cultivate mycelium.

The demonstration ended with a question-and-answer session. Hedstrom finished by recapping the goals of the project (reduce wildfire risk, improve forest health and deal with excess biomass) and the need to continue monitoring the project to see how successful it is in decomposing biomass and creating nutrient soil.

For additional information, check out these websites: Boulder Mushroom: bouldermushroom.com; Boulder Watershed Collective: boulderwatershedcollective.com; Grama Grass and Livestock: gramagrasslivestock.com; and Boulder Office for Sustainability, Climate Action and Resilience: bouldercounty.gov/environment.