What's Happening Beneath the Fallen Leaves This November

Field report

From a frenzy of leaf decomposition to the quiet work of soil organisms, this month's cool damp earth is alive with hidden activity.

As October winds down, it takes with it the last of the bright canopy, the final warm afternoons, and the hope of any remaining summer, so it's time to bundle up and turn our attention to the damp, earthy month of November. What can we expect from the forest floor during our transition to winter? Grab a cup of hot cider, shake out that scarf, and let's look at a few of the highlights happening right beneath our boots.

A Massive Pile of Fallen Leaves Begins Its Transformation (Early Nov.)

First things first, you can continue making plans for Thanksgiving. Those fallen leaves in your yard will not sit there forever — they will break down with remarkable speed. That said, this is a surprisingly rapid transformation by ecological standards.

Even more remarkable, the leaf layer was only completely deposited in the last few weeks and is estimated to be nearly a half-foot deep in places. If you picked up a handful of that leaf litter, it would contain (depending on the tree species) the energy equivalent of billions of tiny organisms at work. The largest earthworms in the pile can process their own body weight in leaves every single day.

How to observe this natural process? According to soil ecologists, simply kneeling down and carefully peeling back the damp leaf layer should reveal a peek at the busy decomposer community underneath. Catch ya later, fallen leaves — see you as soil next spring.

Gain a Deeper Appreciation of Soil as Living Skin (Early Nov.)

Yes, the end of Daylight Saving Time is believed by many to be an outdated and terribly inconvenient idea. But if you want to put a positive spin on the upcoming "fallback" slated for much of the United States on November 6, how about an extra hour of morning garden time — or soil exploration?

The return of Standard Time means early morning light for gardeners, which is good news for anyone who likes to watch dew on spider webs, but not so great if you prefer afternoon walks. We know it's not as dramatic as an extra hour of sleep, but perhaps we can tempt you with the eerie world of soil organisms working through the night?

Witness the Incredible Fungal Networks Blooming After Rain (Early Nov.)

This month's fungal bloom, also called the "frost mushroom" season, reaches its peak on the damp mornings of early November. Fitting for something that seems to appear overnight, this flush of fungal fruiting bodies, one of the most prolific of 2022, will emerge from the dark, damp soil.

Starting about three days after a good rain, the fungal threads hidden beneath the soil will begin to push their fruiting bodies slowly above the surface, reaching peak bloom around a week later. At this point, the forest floor will glow with eerie colors — the rusty red of russulas, the ghostly white of oyster mushrooms, the golden yellow of chicken of the woods.

"Mushrooms ... reflect the hidden world beneath our feet," mycologist and author Pamela Grey tells Nature Notes. "A flush of fruiting bodies is created by moisture from rain and dew ... decomposing wood and leaf litter all feeding the vast underground network that connects the forest."

Earthworms Reach Peak Surface Activity (Mid-Nov.)

Some of the most important creatures in the soil and roughly a thousand times more numerous than you'd guess, earthworms will reach their yearly peak surface activity in November. On damp evenings, they'll be at their most visible for the year, though dry conditions from a late frost will spoil any chances for spotting them easily. Shine your flashlight on the wet leaf litter all night long to see if you can spot these cool, slimy ecosystem engineers.

Catch a Potential Surge of Decomposition Activity (Mid-Nov.)

This month is full of forest floor doubleheaders. First up are the spectacular decomposition surges, also known as the "Halloween melt" to some leaf-litter enthusiasts. Though the process lasts from roughly October 13 to December 2, the best time to catch it in all its steamy, fragrant action is the damp mornings of November 11-12.

The decomposition wave, driven by fall moisture and temperature swings, is known less for its volume of visible organisms and more for how exceptionally intense the breakdown can be. (See the photo above for some examples.) This year is reportedly slated to be a good one, with soil ecologists noting a bump in decomposition rates every seven years: "2008 and 2015 both produced remarkable fungal flushes," they note. "2022 may be the next opportunity."

Faster and more complete decomposition is a good thing, since the mostly (88%) bare tree canopy will do everything in its exposing power to reveal all but the most deeply buried decomposer activity.

Welcome Back the Soil Food Web in Full Force (Mid-Nov.)

Hidden beneath the leaf litter since the start of summer, the classic soil food web will make its return to the damp forest floor this month. One of the most recognizable ecological communities, ranking right up there with the coral reef and the tide pool, the soil food web is easy to spot thanks to its key players: bacteria, fungi, and protozoa.

The soil's most visible representative is the earthworm, one of the largest organisms in the underground world and poised to deliver a spectacular contribution. According to ecologists, earthworms process incredible amounts of organic material — as much as two tons per acre per year. When that happens, the resulting nutrient-rich castings reshape the forest floor, potentially even outshining the contributions of all other soil organisms combined!

A Good Year for Spotting Salamanders Under Logs (Late Nov.)

Driven by moisture streams left behind by autumn rain systems that will return to our region in full force come spring, salamanders are a moderate-sized group with a peak display of about 10-15 individuals per log turned. The amphibians are active through most of November, but the night of peak activity this year is around November 18 — a good thing, too, since cool, damp conditions will keep the soil relatively moist.

Ecologists are predicting a stronger-than-usual salamander season for 2022, with the potential for an outburst of upwards of 300 spotted salamanders emerging over the course of one rainy night. Like other amphibian events, this one will be best observed after dark. Turn your flashlight toward the forest floor near vernal pools, where the spotted beauties appear to congregate.

It's worth noting that salamanders are responsible for some of the most spectacular wildlife spectacles ever witnessed by humans. Every few years, when conditions align perfectly, forests erupt with mass migrations of thousands of salamanders crossing roads on rainy nights. The last big one, in 2001, featured hundreds per hour crossing a single lane. The one in 1966? Downright magical.

"Salamanders began to appear by 10:30 p.m.; there were about three or four every five minutes," recalled naturalist Christine Downing, one of many who wrote in to wildlife organizations to share their experiences. "At the time that seemed extraordinary, but by 12:30 a.m. it was raining salamanders across the entire forest floor. We were in a dark, rainy valley bowl, rimmed by mountains; the Appalachians were in the west. By 2:00 a.m. it was a blizzard of amphibians. There was the unnerving feeling that the whole forest was alive and moving. Salamanders filled the entire path to the tree line, yet it was nearly silent. If these salamanders had been hail, we wouldn't have been able to hear each other. If they had been a show of fireworks, we would have been deaf."

Rich Dark Soil Follows November's Leaf Fall (Late Nov.)

A heavy leaf fall will bring excellent soil-building conditions, reaching its peak around November 23. Interestingly, this year's leaf drop is also exceptional, so-called for when a particularly productive growing season results in an unusually thick canopy to shed. While summer's full canopy is a marvel to see filling the sky, this November leaf fall will be quiet and steady and will usher in several weeks of beautiful dark, rich earth for soil organisms to thrive beneath.