Thursday, March 26, 2020

Snags and Nurse Logs on the Forest Lodge Nature Trail

Although the depths of winter have passed, this is the season when we northerners really feel the cabin fever. Gone are the freshly groomed tracks on the ski trails and dry, fluffy drifts. Now the weather alternates between slush and sleet. Warm days are lovely, of course, but they make the freezing temps that follow just a little more frustrating. 

This year, mud season will be much harder. Without the option to travel south for a break, there’s a good chance some of us will go stir-crazy! One nice thing about living in the Northwoods, though, is that our vast natural areas provide us with excellent options for social distancing. The Forest Lodge Nature Trail is one of those options. This 1.5-mile loop trail is dotted with numbered posts that correspond to an interpretive booklet. I’m updating that booklet this spring, and sharing the new text with you. 

We started the trail by priming our senses: listening to birds, smelling sweetfern, and remembering the sweet taste of ripe blackberries. We walked through an old field crammed with young white pines just getting their start, and entered a dark, mature pine forest with huge stumps, reminding us of the big trees who once dominated the landscape. 

In the midst of that mature pine forest, we now come upon the skeleton of a tree. Its bark lies in piles at its base. The top, and most branches, are gone. Holes riddle its pale trunk. 

Life after Death
This old, dead tree was once a stately white pine. The low limbs on this snag are a clue that the pine was growing in a field. As the years went by, this tree’s seeds grew up to become many of the younger white pines in the surrounding forest. 

Although this tree has been dead for many years, it still supports an abundance of life. Insects like carpenter ants tunnel through the trunk. Hairy, downy, and pileated woodpeckers can easily pick away at the soft wood in search of the larvae of ants and other insects. Big cavities house the nests of woodpeckers, chickadees, nuthatches, flying squirrels, and owls. Do you see the pile of pine cone bracts on the ground? A red squirrel sat there to shuck and eat the seeds out of pine cones. This animal’s trash heap is called a midden. 

Before it died, only the outer layers of wood and bark, the twigs, the roots, and the needles of this tree were alive. Now the living, breathing cells of bacteria, fungi, and insects burrow through every inch of the trunk. Some ecologists say that a tree is more alive when it’s dead. 

What do you think?

Nurse Stump or Nurse Log
As old stumps and fallen logs decompose, they become the perfect place for tiny seeds to get their start. Mosses and lichens like this habitat, too. A balsam fir seed fell onto this stump. It found a good home with more sunlight, more nutrients, fewer fallen leaves, fewer dangerous bacteria, and enough moisture to grow. 

The roots of the new tree will grow around the stump or log and into the ground. The old tree will continue to rot away. Eventually the log will be gone, and you will just see a funny-looking tree up on stilts!  

As you continue down the trail, look for nurse stumps and logs and the new life they support.

Lichens and Mosses
Do you see the green stuff on the bark of a nearby birch tree?

These mosses and lichens are using the tree trunk as a ladder to the sun. They do not harm the tree. Both organisms use sunlight to make food from water and carbon dioxide during a process called photosynthesis. Mosses often look feathery, fuzzy, or like tiny trees. They are tiny, bright green plants with simple leaves that soak up water like a sponge. Moss also dries out quickly, but that’s OK. When water returns, moss can spring back to life in as little as 20 minutes. 

Here's a luscious patch of moss right next to the trail! Photo by Emily Stone.

Lichens form through a partnership between a fungus and an alga. The fungus provides the structure that holds them both onto the tree. Inside the structure, little cells of algae do photosynthesis and make sugars that feed them both. Lichens can be pale green, gray, black, yellow, or even bright orange. They can look like a leaf, a crust, or even tufts of hair. Without the algae, the fungus would starve. Without the fungus, the algae would blow away. Together they can grow on bare rocks and even survive in outer space. Despite their toughness, lichens will die if there is too much air pollution. 

This birch tree near the beginning of the trail has some really lovely patches of Common Greenshield Lichen on its trunk. Photo by Emily Stone. 
Lichens can be bright colors!

Continue looking for lichens and moss as you walk down the trail (or even into your own backyard). How many different kinds can you see?

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at and at your local independent bookstore, too. 

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is currently closed due to COVID-19, but we're still building our new exhibit and bringing you educational content. Connect with us on Facebook and Instagram to see what we are up to.

Thursday, March 19, 2020

Preventing Oak Wilt: A Team Effort

Earlier this winter, I chose a bluebird day to swoop joyfully around the 16k loop at the Rock Lake Ski Trails. Fox tracks trotted over the recent grooming, making perfect imprints in the light dusting of giant flakes that had fallen in the pre-dawn hours. The surface of every drift sparkled among stately trees.

Fox tracks trot along the ski trail. Oaks are important wildlife trees. Their acorns feed mice. Mice feed foxes. The loss of our oaks will impact more than humans. Photo by Emily Stone.

These ski trails are known for their rollercoaster hills. In many places, your exhilarating downhill momentum will carry you all the way up to the crest of the next rise. As I was doing just that—coasting up the other side of a hill out on the farthest part of the loops—flash of pink caught my eye. Several trees in a cluster were ringed with neon flagging tape. My heart sank. Not here, too!

Foresters and land managers all over northern Wisconsin are working hard to identify oak wilt infections and get them contained before they spread. These trees were marked and girdled as part of that effort. Photo by Emily Stone.

Sidestepping over to the closest one, I scanned the trunk until I found it—right at snow level was a saw mark in the bark, completely encircling the tree. The cut had done its job of preventing the flow of water and nutrients from roots to crown. The result was death. This oak had been girdled purposely.

While the dead trees made me sad, I wasn’t mad at the person who had cut into them. Some responsible forester was just doing their best to prevent the spread of oak wilt.

Oak wilt is a fungal pathogen that kills trees in a single season. While it’s already widespread in southern Wisconsin, it has only just arrived here in the north in 2018.

Sap beetles in the family Nitidulidae are one of the main vectors for oak wilt. When an oak tree is injured—by a bulldozer, trail groomer, wind storm, etc.—sweet juices begin oozing from its wounds, and that scent lures in hungry beetles. If those beetles have already been eating from a tree infected by the oak wilt fungus, they will transport spores and inoculate a new infection.

The fungus works quickly to invade the tree’s water conducting system. While white oaks seem to be able to mount a defense and exhibit a degree of resistance to the disease, the red oaks that are dominant up here don’t stand a chance. The oak’s leaves wilt from the crown down, in the middle of summer, and within a month the tree is dead.

Beetles aren’t the only way that oak wilt spreads, though. The fungus can travel through the tree’s roots, pass through root grafts with nearby oaks, and kill them, too. I’ve written about the incredible connectedness of trees and fungi in the “wood wide web,” and how those networks facilitate communication, cooperation, and forest health. But sometimes—as we humans are discovering—an interconnected world is a more dangerous one when a new disease shows up on the scene.

One of these oaks probably died naturally from the fungus. The other, potentially connected trees, were girdled and painted with herbicide. While it sounds drastic, this is the most reliable method to make sure that there aren’t infected root grafts that will spread the fungus below ground. You might even call it a type of tree quarantine, or social distancing.

This oak tree has been girdled in order to contain an oak wilt infection. The two cuts sever conductive tissue and prevent water and nutrients from flowing, thereby killing the tree. Photo by Emily Stone.

By using these precautions, hopefully just a few trees will die, rather than every oak in the forest. They are still salvageable as lumber, and even the fungus-killed trees can be used for firewood if you quarantine the logs under plastic for a year so that beetles can’t access them and spread their fungal spores.

Paul Cigan, a forest health specialist with the Wisconsin Department of Natural Resources, can’t say it enough: the only thing that will prevent oak wilt from becoming a widespread problem in our forests up here is responsible landowners and preventative care. There were 50 new oak wilt infections in 2019. That includes 5 in Sawyer County, 12 in Bayfield County, and 32 in Washburn County. Four of those are in locations—and on ski trails—that are dear to my heart. This disease feels personal.

Luckily, there are many things we can do to prevent oak wilt. The beetle that spreads oak wilt can’t chew its own holes. We can be careful not to make holes for them. During the fungus’s active time, from April through July, how you treat your oak trees can mean the difference between life and death for them. Any sort of wound, whether it’s a scrape from a bulldozer, a pruning cut, a logged stump, or even a broken twig can be the entry point for oak wilt into your forest, and your neighbor’s forest, too.

Using wound-sealer to cover injuries immediately can help. (Beetles can find a new wound in 15 minutes or less!) Paying close attention to your forest is also important. Keep an eye out for oaks with wilting leaves. When caught early by observant landowners and reported to your local Department of Natural Resources office, infections can be contained.

Private landowners are not alone in this fight. Foresters from the counties, the Wisconsin DNR, and the United States Forest Service are working together on their large-scale oak wilt detection and mitigation operations. Aerial surveys with planes and drones, and satellite imagery with computer analysis that can spot sick trees are at the forefront.

Oaks are a major component in our forests, and they are important ecologically, economically, and aesthetically. Preventing oak wilt will be a team effort.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at and at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Pollinator Power exhibit ends after February 29, but our Curiosity Center remains open, and Mysteries of the Night will open on May 1, 2020. Call us at 715-798-3890 or email

Thursday, March 12, 2020

A Walk on the Forest Lodge Nature Trail

Have you ever visited the Forest Lodge Nature Trail? This hiking trail loops its way through beautiful fields, forests, swamps, and bogs near the south shore of Lake Namakagon, about 10 miles east of Cable, WI, on Garmisch Road. The Cable Natural History Museum established a four-mile-long network of trails in 1968, under the direction of our founder, Mary Griggs Burke. In 1999, Mrs. Burke transferred the property that the trail is on over to the Chequamegon-Nicolet National Forest. The Museum and the Forest Service now share the goals of education, research, and interpretive opportunities for the public, and work together to preserve and manage the Forest Lodge Nature Trail.

The main, 1.5-mile loop trail is dotted with numbered posts that correspond to an interpretive booklet that visitors can pick up at the Museum or the trailhead. For almost a year, Museum naturalists, Forest Service technicians, and Wisconsin Master Naturalist Volunteers have been working to update the decades-old booklet. During the next few weeks, I’m going to give my readers a preview of the booklet, and a chance to catch typos or improve the information. I’d love to hear from you!

The trail begins at the edge of a grassy parking area, tunnels through some dense white pines, and then emerges into a small meadow filled with milkweed and edged with blackberry brambles and white pines. The first numbered post is on the far edge of the meadow.

Every living thing depends on their senses to help them survive. Humans use sight, smell, touch, hearing, and taste to interpret our surroundings. Non-humans can even sense things like the Earth’s magnetic fields, polarized light, and electric charges in flowers.

Try standing very still and quiet; what do you hear? Cup your hands behind your ears and face the direction of an interesting sound. Can you hear the hum of a nearby bee, or a conversation among crows?

Take some deep breaths. What do you smell? Try rubbing a drop of water under your nose. Can you smell more now? A plant called sweetfern grows nearby. It’s not really a fern, but the lacy leaves of this woody shrub smell spicy when crushed between your fingers.


Blackberries also grow nearby. Their plump fruits ripen from green, to red, to black in late summer. Touching their sharp thorns is no fun, but you may carefully pick and eat the sweet, ripe fruits.

Blackberry in bloom, with green fruits developing.

While you hike, remember that all of these beautiful flowers and natural objects you see, hear, feel, smell, and taste are part of someone’s home.  

Old Field Succession
Nature is always changing. The area where you now stand used to be a forest. Loggers cleared the forest, and farmers turned the land into pasture. After this area became a nature preserve, the old field started growing back to forest and changing in predictable ways. This is called ecological succession, and it occurs after logging, fires, floods, windstorms, and other disturbances.

White pines are often the first trees to grow in old fields. These evergreen trees have needles that are bundled in groups of 5. To help you remember, think of the fact that W-H-I-T-E has 5 letters.

Because of the bright sunshine in the field, these young white pines grew branches all the way down to the ground. How do you think they will look when they get older?

Young pine trees are taking over a sunny field, and chickadees enjoy the new habitat at the Forest Lodge Nature Trail. Photo by Emily Stone. 

Just ahead, you will enter an older forest. These, too, are white pine trees, but they all grew up together without much space between them. Deep shade has caused their lower branches to die and fall off. Not all of the trees lack lower branches, though. Why might one old tree have grown big lower branches?

Old Growth White Pines
Some of the biggest white pines grew 200 feet tall and 6 feet in diameter. During the intense logging era of 1850-1920, lumberjacks logged this entire area for white pine and hemlock. These trees produced billions of board feet of lumber that was used for construction, furniture and paper production. 

Not all uses of white pine require that you cut it down. White pine needles are rich in vitamin C, and can be used to make a tea.

As you walk the rest of the trail, look for decaying stumps throughout the forest. These are the remnants of white pines that stood here 100 or more years ago. 

Please join me again next week to explore more of this beautiful trail!

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at and at your local independent bookstore, too. 

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Pollinator Power exhibit ends after February 29, but our Curiosity Center remains open, and Mysteries of the Night will open on May 1, 2020. Call us at 715-798-3890 or email 

Thursday, March 5, 2020

Winter Adaptations of 3rd Graders

"Awooooo!” My best impression of a wolf howl rose over the crunching of snowshoes and little voices. Gesturing to the group of third graders from the Hayward Intermediate School, I invited them to howl back. The choir that responded sounded nothing like wolves, but it was music to my ears nonetheless. So was the expectant silence that followed, since these kids were wise to the fact that I’d howled to get their attention.

“We’re going to hike like a pack of wolves today,” I declared. “Do you know how wolves walk when they’re in deep snow?” I led this same snowshoe hike four times over the course of two days, and in each group there was one outdoorsy kid who knew. Wolves walk in a single file line and step precisely in the footprints of the wolf in front of them. The kids understood the benefits of the wolves’ behavior intuitively. Who hasn’t made their own life easier by following in someone else’s footsteps through deep snow?  

With one last admonition to walk in a single file line, I howled again, and they howled back as we started up the trail. 

The Mammal Tour on the Ridge Trail is a wonderful community resource. The 1.1-kilometer loop trail is the easiest of several snowshoe trails at the North End Trailhead just south of Cable, Wisconsin, and the Museum and our partners have created a self-guided interpretive trail along its length. There are life-sized silhouettes of local mammals cut out of metal. (The original wooden ones were destroyed by a porcupine.) Trail guides available at the trailhead contain a map of the trail, plus images, information, and tracks for all the mammals. 

Out in the woods, my plan was to teach about how animals confront the cold and snow head-on. Back in the Museum’s education room, Haley Appleman, the Museum’s naturalist, was teaching the other half of the group about animals that migrate and hibernate.

Our first interpretive stop is at the wolf and deer silhouettes. Wanting to wow them with the thickness of a wolf’s fur, I walked over to one of my helpers—a third grader carrying a heavy orange backpack. When I unzipped the pack and started pulling out a huge wolf pelt, a wave of surprised comments rippled outward. The helper was the most surprised of all. “You mean I was carrying that on my back!?”

Photo by Alison Menk

We also compared wolf tracks to deer tracks. Wolves’ relatively large feet act like snowshoes and help them run on top of crusty spring snow. Deer hooves punch through more easily. One dad with long legs and without snowshoes offered to demonstrate the difference. A few steps off the hard-packed trail and he was sinking in up over his knees. “Is that pretty easy?” I called up to him. “Nooo,” was his breathless reply. We all laughed. 

Our next stop was below the form of a flying squirrel. Unlike wolves, they don’t have thick enough fur to sleep out in the open. For warmth, flying squirrels huddle together with their friends in a hollow tree. Handing out durable thermometers to small groups of kids, I challenged them to see how much heat they could generate by huddling together with their friends. Most groups brought the temperature up to 40 or 50 degrees, but one group of girls used their breath and registered over 70 degrees!

At a set of weasel tracks bounding two-by-two from tree base to fallen log, I paused and pulled out two small furs. One was almost pure white; the other was brown on top and white on the belly. Both tails were tipped with black. Short-tailed weasels, also called ermine, turn white for the winter. The black tip stays as a decoy. Hungry red-tailed hawks will aim for the conspicuous tail spot…and miss the vital organs. In my opinion, these are the softest furs at the Museum, and every kid who removed their mittens in order to feel them was suitably impressed. 

Weasels don’t need large snowshoe feet because they spend most of the winter tunneling under the snow. Snowshoe hares, on the other hand, combine all of the best winter adaptations. They turn white, they have giant hind feet, and they have warm fur. Out of a second volunteer-carried backpack, I pulled track molds of both snowshoe hare and cottontail rabbit hind feet. The relative sizes were pretty similar to the kids’ feet with snowshoes and without. By this point, many of the snowshoes had fallen off and were being carried, but the kids still appreciated the comparison. 

“Awoooo!” I called again, and “Awoooo-oo-oo!” my wolf pack replied as we began the last stretch of their hike back to the bus. With the end in sight, tired legs were forgotten and the group’s chatter turned to comments like “that was so fun,” “we hiked so far,” and “I wish we could go farther.” This, of course, was music to my ears. 

Author’s Note: Portions of this article appeared in 2018. I say almost the same things on this field trip every year!

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at and at your local independent bookstore, too. 

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Pollinator Power exhibit ends after February 29, but our Curiosity Center remains open, and Mysteries of the Night will open on May 1, 2020. Call us at 715-798-3890 or email