Rethinking Black Morels: New Evidence That Morchella septentrionalis Feeds on Decay, Not Trees

For decades, Morchella septentrionalis — Minnesota’s black morel — has been labeled a mycorrhizal species, supposedly living in a mutually beneficial relationship with trees. It's what you'll find written in field guides, and it's been repeated often enough to sound like settled science.

But after more than a decade of picking black morels across northern Minnesota, I’ve come to a different conclusion:Morchella septentrionalis might not be mycorrhizal at all. In fact, I believe it behaves more like a saprotroph — a fungus that feeds on dead wood and roots, not live trees.

And I’ve got the field observations to back it up.

How well do we really know Morel mushrooms?

What the Woods Showed Me

Over the years, I’ve watched black morels consistently fruit in second-growth aspen stands — typically 10 to 20 years after a logging event or other disturbance. This window seems to line up perfectly with when aspen forests naturally self-thin — when trees compete for space, and many start to die off underground.

The mushrooms almost always appear in areas rich with:

• Decomposing surface roots

• Rotting logs

• Moss-covered downed wood

  
  
  
  

  

  Typical early fruiting of M. septentrionalis from mossy, decaying wood — not from mineral soil.

  
  

In some cases, I’ve found black morels growing directly from rotting wood, and even once emerging straight out of a dead trunk above ground level. Not tucked politely at the base of a tree — actually from the wood itself. This isn’t the behavior of a fungus feeding from living roots.

Rare but important observation — Morchella septentrionalis growing directly from a dead aspen trunk.

The Aspen Connection

Aspen stands are dynamic. They're aggressive growers after disturbance, but they don’t stay crowded for long. Around 8–10 years in, the weaker trees start to die back naturally — a process called self-thinning — which sends an enormous amount of dead organic material into the soil.

In site after site, black morel flushes coincided with the period when buried roots and woody debris were rotting underground.

The pattern is hard to ignore:

• Fruiting starts around 10 years after disturbance

• Peaks when underground root death is at its highest

• Fades away as the stand matures, canopy closes, and easy food disappears

  
  

  

  Aspen stand ~15 years post-regeneration — prime fruiting habitat for black morels in Minnesota.

  
  

Saprotroph or Shape-Shifter?

Given this, I believe M. septentrionalis functions primarily as a saprotroph — feeding off dead material — rather than as a partner to living trees.

There’s also the possibility that it’s facultative: Capable of forming weak associations with living roots early on, but primarily thriving when given access to dead organic matter. This flexible strategy (called facultative biotrophy) is gaining recognition in fungal research, even though it's rarely mentioned when talking about morels.

Clear evidence of saprotrophic behavior — Morchella septentrionalis fruiting directly from decomposing aspen wood.

And importantly: Despite all the claims of mycorrhizal status, no study has ever confirmed mycorrhizal structures (like Hartig nets or mantles) for M. septentrionalis under a microscope.

What This Means for Foragers and Researchers

If black morels feed on decay instead of partnering with trees, it changes where — and when — we should hunt them:

• Focus on aspen stands 10–20 years post-logging or burn.

• Look for mossy areas, downed wood, and dying trees.

• Understand that they are part of the forest’s recycling team, not just its symbiotic web.

  
  

It also means it's time to rethink what we assume about morels based simply on where we find them.

Fruiting directly from the decay zone — not mineral soil — beneath moss and leaf litter. The kind of moment that makes you stop in your tracks.

The Next Step

I’m continuing to document and share observations, and I encourage anyone finding black morels growing from rotting wood to photograph it — and maybe even save a few notes.

We don't have all the answers yet.But I believe Morchella septentrionalis is trying to tell us its story — we just need to slow down and pay attention.

Even in a quiet patch of moss and rotting leaves, Morchella septentrionalis finds a foothold — hinting at a life fed by decay rather than tree roots.

🍄 Want to see these mushrooms for yourself?

Join us at the Black Morel Hootenanny — Minnesota’s one-of-a-kind morel celebration happening May 16–18 in Grand Rapids.We’ll cover foraging, identification, cooking demos, and more — all built around the legendary black morel.

🎟 Get your tickets and full weekend info here: https://www.gentlemanforager.com/black-morel-hootenanny Let’s hit the woods together.