Diverse Decomposers

Chicken fat mushrooms (Suillus Americanus) grow near white pine trees.

When I was little, I thought that fungi just meant the small, brown squishy mushrooms that appeared in the lawn after a wet spell — and I was squeamish about them. But that’s only a small part of the story. The hidden world of fungi runs deep within the soil like strands of microscopic silk. I imagine these tiny fungal strands as threads of life woven in a network in and around plant roots. What we see are the strange and often beautiful fruiting bodies — what we typically call a mushroom or toadstool — growing on a tree, a log, the ground, or some other food source. This visible part of a fungus produces reproductive spores.

Russulas often grow near oak trees.

In fact, fungi are one of Earth’s key recyclers of carbon and other materials. Along with bacteria, earthworms and other soil organisms, fungi decompose organic matter to release and recycle nutrients, feeding themselves and others through this process.

Bracket fungi and lichens grow on a log along the Kettle River.

Fungi are not plants; they have no chlorophyll, leaves, roots, flowers or seeds and do not make their own food. They are primarily strands called hyphae, which secrete enzymes that break down organic matter, such as leaves, dead trees, and animal remains. Scientists currently think that land fungi split off from the animal kingdom around 1.3 million years ago — about 500 million years before plants.

Tiny slime mold sporangia grow on a rotting log. (Slime molds are related to, but different than, fungi.)

Though some fungi are parasites that damage plants and other living organisms, mycorrhizal fungi form a symbiotic partnership with plants in which both benefit. The fungi obtain nutrients that the plant produces in photosynthesis. The fungal hyphae, in turn, break down organic substances releasing nitrogen, carbon, glucose and other nutrients, which they pass along to the roots of plants without parasitizing them. Many fungi also store carbon, meaning that less is released into the atmosphere as carbon dioxide. All winter long fungi will nourish the soil for spring growth. As I walk on these autumn days, with so many leaves underfoot, I like to think about how they will be decomposed and used again in the spring to help create next year’s new life.

Peeling Puffballs (Lycoperdon) often grow in sandy, open areas, such as roadsides.

Though some fungi are harmful to plants, humans and other organisms, many provide antibiotics and food in addition to forming nourishing soil. So the next time you spot a fungus and think it’s gross, remember the benefits that many fungi provide to nature, the food chain and to us. Here are a few fungal fruiting bodies that I’ve seen growing in the woods this autumn. Fungi often are difficult to identify, so I don’t know all of their names, but I appreciate their shapes and colors.

Tiny orange Mycena toadstools growing in moss.

The underside of this Russula mushroom cap shows the spore-producing gills.

A silvery blue-capped fungus pops up through moss near aspens and pines.

An autumn toadstool grows under bur oaks next to the riverbank.

Amanitas grow in deciduous and mixed woodlands.

White polypore fungi slowly decompose a fallen tree limb.

January Thaw

The week’s mild air and slow, steady melt have given voice to the first cardinal songs and chickadee whistles. Robins also call softly throughout the neighborhood. It’s too early to look for bulbs and other new life in the garden, but there’s a lot happening under the snow. I’m excited about the thaw and had a peek at what goes on under the white blanket during the winter!

Where the snow melted away from the lower stalks of a climbing rose, I found bracket fungus growing on the remains of an old stalk that died several winters ago. I hesitated to cut it down (for fear of damaging the plant) and left it alone. Now, nature is returning it to the earth on its own schedule. The fungus, also known as shelf fungus, breaks down the main components in the dead wood and returns them to the soil.

Bracket or shelf fungus, with their striations, remind me of freshwater clam shells.

Bracket or shelf fungus, with their striations, remind me of freshwater clam shells.

I also found a few patches of bright green moss exposed by the melt. I think it is fire moss (Ceratodon purpureus), which remains green under the snow throughout winter. Like the fungus, it is an ancient plant that evolved more than 500 million years ago. The moss breaks down rock and other components that enrich the soil. Moss also helps prevent erosion by holding water and soil in place. Its fresh spring green is a beautiful contrast to winter’s formal black and white.

Fire moss stays moist and green under the snow. It builds soil and helps control erosion.

Fire moss stays moist and green under the snow. It builds soil and helps control erosion.

Both plants replenish the earth and prepare for spring growth. So, in a few months, as you enjoy the beauty of spring bulbs, budding trees and blossoming perennials, remember the lowly fungi and moss that return nutrients to the earth and restore soil to nourish the circle of life.

Living things like this mourning cloak and common milkweed, benefit from the hidden actions of fungi and moss under the snow.

Living things like this mourning cloak and common milkweed, benefit from the hidden actions of fungi and moss under the snow.

Autumn Photos and Phenology

Seasonal changes happen quickly in Minnesota during October and it’s interesting to watch the progression into autumn. For example, swamp milkweed seed pods break open, male goldfinch feathers transform from bright yellow to olive green, chipmunks and other rodents stash nuts and seeds for the winter, and bees and most other insects have either died or are hibernating until spring.

Naturalists use the term phenology to refer to these changes.  Phenology is the study of the changes that occur in plants and animals from year to year — such as flowering, ripening of fruit and nuts, emergence or disappearance of insects, and migration of birds — especially the timing and relationship of these events with weather and climate.  It also can include other observations, such as the occurrence of the first frost, the date on which a body of water freezes, and when specific constellations are visible in the sky.  Here are a few examples of current autumn phenology that I photographed along the Snake River in Pine County, MN:

 Northern red oak leaves begin to change color.

Northern red oak (Quercus rubra) leaves begin to change color.

Wild rose hips ripen to cherry red.

Wild rose hips (Rosa acicularis) ripen to cherry red.

Swamp milkweed (Esclepias incarnata) seeds pods release their silky seeds.

Swamp milkweed (Esclepias incarnata) pods release their silky seeds.

An eastern chipmunk collects acorns, hickory and hazelnuts in its pouches to store in its den for the winter.

An eastern chipmunk stuffs bur oak acorns into its pouches to store in its den.

Puffball mushrooms are common in autumn.

Puffball mushrooms appear in autumn.

Everyone who observes nature and records their observations contributes to the science of phenology.  If you’re interested in contributing your own observations, there are several organizations online, including:  “Nature’s Notebook” at the USA Phenology Network, the University of Minnesota’s Minnesota Phenology Network  and the National Science Foundation’s “Project Budburst”.