Birches, A Forest Gift

Gray birches are native to Northeastern North America and like their close relatives, the Paper birches, are a pioneer species, springing up in abandoned fields, woodland edges, or disturbed areas. After land has been logged, they are one of the trees along with poplar and willow that germinate first, providing much-needed shade for second succession trees and plants.

Gray and Paper birch are easily confused as both have white bark, and they often grow together in the same habitat. However, they can be easily distinguished by bark texture or leaf shape. Gray birch bark doesn’t peel and has sharply serrated leaves. White birch has leaves that look and sound more like those of poplar. Both species are almost identical genetically.

Neither White nor Gray birch is a long-lived tree, but those that find enough moisture will grow into sturdy adults that may live for more than a hundred years. I have a few like this on my property.

Prior to the arrival of European settlers, Gray birch was held in high esteem by many Native American tribes. The Iroquois and Mi’kmaq tribes valued this tree for its medicinal properties especially useful for treating infected cuts and wounds(reinforcing the reality that native peoples have access to information that science is just getting around to learning today). Northeastern Tribes made wide use of the outer bark of white birch for constructing canoes and making wigwams. Birchbark was also used to make hunting and fishing gear; musical instruments, decorative fans, and even children’s sleds and other toys. Today, the wood is used primarily for pulp, furniture, and firewood. I am presently burning last winter’s birch in my stove, and I use the bark for kindling.

Dr. Suzanne Simard was the first Forest scientist to discover that when Paper birch was allowed to grow along with Red cedar and Douglas fir in the Northwest the birch protected the latter from Armillaria, a fungus that fruits as a tasty mushroom that can also become an aggressive root pathogen that will kill any tree in its path, especially those grown on plantations (plantations are artificial forests composed of one species like fir or pine that are grown quickly to be harvested for cash. Foresters clear cut forests and create these plantations even though it has been proven that in some places 57 percent of these fake woodlands succumb to disease or death because the trees can’t root properly).

Paper birch contains bacteria with antibiotic properties that help protect conifers from other diseases as well. I suspect that Gray Birch protects our eastern forests in similar ways that Paper birch does in the west because the two share almost identical DNA structures. Birches have another advantage. When the trees come down in storms the logs break down very rapidly enriching the soil with humus. Birches support the underground mycelial networks that connect all trees creating pathways for nitrogen, carbon, sugars, etc. to be exchanged. Simard(along with a number of other forest scientists) argues that tree plantations would benefit greatly from allowing birch to grow alongside fir because of their protective ability. Forest scientists have learned that any forest lacking in diversity is weakened in ways that we don’t yet understand.

Birches have other attributes worth mentioning. Birch seeds are an important food source for many winter birds, including goldfinches, pine siskins, northern juncos, blue jays, chickadees, and sparrows. Go out any morning after a windy winter snowstorm and you can see that the surface of the snow is covered with tiny birch seeds. Juncos, blue jays, titmice, chickadees, cedar waxwings, ruffed grouse, and other birds also eat the early spring buds. While the seeds are important for wildlife including small mammals, the trees are used in many other ways too. Snowshoe hares and cottontails browse the twigs. Birch catkins also attract many insects (providing the first food for bees), which in turn attract large numbers of migrating warblers; they also provide some of the first nourishment for black bears.

Birches are also hosts for the caterpillars belonging to several species of butterfly; the list includes tiger swallowtails, white admirals, mourning cloaks, and tortoiseshells.

Birches can also be important nesting sites for vireos, as well as for cavity-nesting birds like chickadees and woodpeckers. Small strands of birch bark are the key materials used by vireos in their hanging nests, while many other birds and red squirrels incorporate this material into nest and den linings. In addition, yellow-bellied sapsuckers regularly drill into birches to allow sap to run out. Boring holes into birches attract ants for others to feast upon. As you can see birches are important to a wide variety of species.

Anyone that pays attention to trees knows that both Gray and to a lesser extent White birch are vulnerable to high winds and ice. During last winter’s ice storm in December, I was devastated because I lost so many birches. For the remainder of the winter, I looked at these bent and broken trees with despair.

When spring came I was overwhelmed with the amount of debris that I thought I had to clean up. I couldn’t accept that in an intact forest like mine, it is natural that birch trees will fall in heavy winds, ice, and snow. I had to be reminded by Suzanne Simard that fallen birches provide rich humus and open areas to more sunlight without disrupting the integrity of the forest itself. It’s not as if I wasn’t aware that my woods were peppered with fallen birches in various stages of decay; the difference was that they hadn’t all come down at once like they did in one microburst.

As spring progressed into early summer I witnessed how the dying birch created more habitat for birds and young saplings. One big cluster of fallen birches created a protected nesting site for the grouse to raise her family on the other side of the fence. As more light reached the forest floor new wildflowers appeared. My Lady slippers sprung up after I cleared some debris below the house, and later, fragrant pyrola carpeted the ground. This fall I continue to note how fast the logs decay and how rich the earth smells whenever I pick up parts of a rotting log, something I do quite frequently now. Wood frogs, peepers, and toads hid out here during the scorching summer heat. When I dig below the surface just an inch or two, I can see the colorful complex mycelial network that disappears into leaf litter.

It has been almost a year now since that brutal storm and I have come full circle. Although I am hoping that this winter will be kinder to all trees than last winter was, I am also aware that with Climate Change upon us that more extremes are ahead. I hope that the birches will continue to teach me a lesson about acceptance of what is, and what will be. When I look at the birch logs stacked for this winter’s firewood or I walk by logs crisscrossing the ground in my woods all I can think of is that these trees are caring for the forest as a whole not just by living but also by dying, and I give thanks for each one that is actively participating in the endless circle we call life.

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