Implanting mycorrhizal fungi

November 9, 2016

Mauricie’s wood marketing board project to seed mushrooms in the forest by means of spores is a smoke screen that creates false expectations, according to Fernand Miron, biologist.

This project, launched in October 2016 by Mauricie’s wood marketing board, is designed to attract owners who are eager to increase revenue from their woodlands by planting high quality mushrooms that can be sold at elevated prices to restauranteurs and in international markets. The problem is that implanting troops of mycorrhizal fungi associated with the roots of trees is not accomplished simply by depositing old fruit bodies in the soil of the forest floor. If it was that easy, everyone would be doing it and the market would be quickly inundated.

Eric Danel, researcher at the Mycology and Pathology Department of the University of Sweden, has managed to associate Chanterelle mycelia with white spruce seedlings and has commercialized a limited number. They will begin to produce Chanterelles 15 years after their implantation at the site. If we could do the same with jack pine seedlings associated with Pine Mushrooms, the harvest would begin in 60 years.

The ground is already filled with the mycelia of fungi that vigorously defend their habitat to prevent other mushrooms from replacing them. Unless there are major changes in the environment, implantation isn’t possible. Take, for example, a maple grove. Each year, maples drop hundreds of thousands of keys on the ground; some of them germinate, giving rise to seedlings tens of centimetres tall that line the maple grove floor. None of these seedlings will grow into a tree as long as the maples already growing there exist. After 150 or 200 years, when the trees die or are cut down, only a few seedlings will grow up to establish a new generation of mature trees.

It’s important to know that mushroom mycelia in the soil can live for hundreds of years if their habitat continues to be favourable. For instance, after a forest fire, fungal mycelia continue to live in the ground waiting for a new stand of trees to colonize the area and reach an age that allows the mycelia to associate with their roots. If we wish to break this cycle, we should plant white spruce seedlings or jack pine already associated with top quality mushrooms in favourable soil, and hope that the association persists for a certain percentage of them. Such seedlings do not exist.

The implantation of new groves of mushrooms associated with the roots of trees is a complex operation that we do not foresee being realized in the near future.