Harvesting fresh shiaitaki mushrooms outside your back door is a special treat my friend Carol and her family have been enjoying for years. Their Sequim backyard is hardly a forest but thanks to mushroom advocate Paul Stamets they have an alder log inoculated with mycelia that gives rise to the tasty fungus.

Offering “grow your own” mushroom kits is a small part of the work of Fungi Perfecti, www.fungi.com, his Olympia-based company that helps fund his research. 

For mycologist Stamets, fungi have a grander role than providing a mealtime treat: healing Earth’s damaged places.

The beginning of this process is familiar to anyone who has turned over a fallen forest log and seen the root-like mycelia thread through logs and other forest floor detritus. This pale filamentous mycelia is essentially the body of a fungus; mushrooms are fungi’s “fruit.”

As mycelia grow, they honeycomb the soil, creating tiny pockets for water. Holding some 30 times their own weight, they prevent erosion as they transform various forms of cellulose, plant and animal tissues into soil. To accomplish these essential cleanup tasks, they produce an astonishing — and extraordinarily useful — array of enzymes.

Some fungi can attack contaminants with the same chemicals they use to decompose organic matter. Focusing on the fungi of the Pacific Northwest, Stamets has found ways to cultivate pesticidal fungi that trick insects into eating them and others that can break down everything from petroleum to the neurotoxins used in nerve gas.

In “Dirt: The Movie,” he demonstrates how fungi can transform a heap of woody debris into vital, healthy soil in a matter of weeks. Without the assistance of mushrooms, Mother Nature takes a thousand years to produce an inch of soil. Industrialized farming and forestry practices have accelerated the loss of topsoil to unprecedented levels, creating a growing problem for agriculture around the world.

Our loss — on many levels

“It only takes one good rainstorm when the soil is bare to lose a century’s worth of dirt,” says David Montgomery. A University of Washington professor of Earth and space sciences who studies the evolution and structure of the Earth’s surface, he is also the author of “Dirt: The Erosion of Civilizations.”

It’s hard to overestimate the importance of mycelium in maintaining our Pacific Northwest forests. In “Mycelium Running: How Mushrooms Can Save the World,” Stamets nominates a site in Oregon for the title of the world’s largest organism: “This 2,400-acre site in eastern Oregon had a contiguous growth of mycelium before logging roads cut through it. Estimated at 1,665 football fields in size and 2,200 years old, this one fungus has killed the forest above it several times over and in so doing has built deeper soil layers that allow the growth of ever-larger stands of trees. Mushroom-forming forest fungi are unique in that their mycelial mats can achieve such massive proportions.”

In his field studies in the old-growth forests of the Olympics, Stamets is on a special biological treasure hunt for rare mushrooms with anti-viral and anti-microbial properties. One, the agarikon, now extinct in Europe, was recognized as an aid to healing in ancient Greece. Another may prove effective against multiple sclerosis.

In October 2011, Stamets spoke about his search for medicinal mushrooms, ending with a moving personal story of how his research with turkey tail mushrooms rid his 85-year-old mother of Stage 4 breast cancer. Find his TEDMED talk at Fungi.com or www.youtube.com/watch?v=Mjv8Zj1ABAc.

Forest growth is only a part of the mycelium story. The potential of its medical secrets alone make our Northwest forests invaluable. Its diversity offers other lessons as well. “Biodiversity is the immune system of the ecosystem,” Stamets says.

“We need to understand the language of Nature,” he says; the importance of the language shouldn’t be overlooked simply because we lack the skills to understand it. The world’s ecology depends on it. And fungi may hold the key to unlocking that primal mystery.

Diana Somerville writes about creating more sustainable communities and our personal connection with the environment. A Clallam County resident, she’s a member of the National Association of Science Writers, the Society of Environmental Journalists and the American Society of Journalists and Authors. Reach her at www.DianaSomerville.com or e-mail columnists@sequimgazette.com.