Morels & Fire Ecology

Morels are the poster child for Nontimber Forest Products (NTFP), for although people have tried for decades to grow them commercially, no one has yet been able to capture the flavor of the wild morel. Like Chanterelles, Boletes, Sweet Tooth, and other species of mycorrhizal fungi, morels have evolved in close association with trees, and actually form tissue called mycorrhizae, in which the fungus and the plant tissue actually grow together and exchange nutrients and fluids.

Since these conditions cannot yet be duplicated in the laboratory, the living forest remains the only source for these sorts of delicious edible fungi. Morels have a complex life cycle, illustrated below. The fungus may grow as a mono or dikaryotic (primary or secondary) (1 or 2 nuclei per cell) mycelium, form asexual spores (from conidia), form sclerotia (non spore producing "resting bodies"), and the well-known fruiting body, the "morel." It takes 10 days for the primordia (infant mushroom) to grow to maturity and produce spores; small light colored morels often are not yet producing spores, so picking small morels breaks the life cycle.

For a discussion on effective mushroom picking, see our page on Ethical Harvesting.

Morel spores germinate and grow rapidly under the proper conditions, but when the mycelia encounter poor conditions, they form scerotia, which in turn produce morel mushrooms. Mystery shrouds the conditions which produce sclerotia and lead the scerotia to produce the morel.

The diagram below is a representation of the morel life cycle (Volk and Leonard 1990, Volk and Leonard, 1989a)." Even a glance at the figure will reveal a stage of the morel life cycle not present in the other cultivated mushrooms: the sclerotium. The sclerotium of the morel is a relatively large structure (1mm -5 cm diameter) composed of large cells with very thick walls that allow the fungus to survive adverse natural conditions, such as winter. In the spring, the sclerotium has two options for germination; to form a new mycelium or to form a fruiting body. Unfortunately for the potential grower, it is very easy to get the sclerotia to form a new mycelium but very difficult to force it to form a fruiting body. Very specific conditions of nutrition, humidity, carbon dioxide levels and temperature must be met for primordia to form. Although difficult, however, this part is relatively easy. The primordium is very prone to abort at this very young stage if not given the proper set of conditions, which may be very different from those that allowed their initiation. It is at best a very tricky business."

Thanks to Tom Volk for this diagram.

The WMMA is sponsoring research to learn more about the growth and development of the morel fruiting body. If you would like to participate - Please check out our RESEARCH Info. Morels may serve as an incubator for some tiny seedlings, as shown here.

Theories abound to explain why morels appear after fires, but that is beyond the scope of this website.

Contact the WMMA for more information.

While the theories about morel growth are difficult to prove, people are nonetheless successful at finding morels in burn areas. The landscape below shows the French Creek drainage near McCall, Idaho after the 1994 fires. This area yielded millions of dollars of morels, in an amazing 56 day season.

This shows a close up of an area where about 10 pounds of morels were picked.