Birch Trees
Phenology – “a branch of science concerned with the relationship between climate and periodic biological phenomena (as the migration of birds or the flowering and fruiting of plants).
No Guide Book Needed
Birch trees are unique. Everyone knows what they look like, and everyone is happy to see them. It doesn’t matter if it’s the middle of winter and you’re walking through two feet of snow, closely watching each step to avoid tripping over a fallen branch or a tangle of briars. You still see the birches rising out of the snow drifts, and you naturally bend your route to pass by the inviting clump you notice just a few yards off to the left. If you stop for a moment to look around, you can identify birches even if they are a hundred yards away. What other leafless trees can you identify so quickly? Even if you can tell a beech from a poplar, are you really that excited by seeing either of these smooth-skinned trees? Do you expect your child or grandchild to recognize either of them? No, but you do teach them that trees with white bark are called “birch trees.”
Different Colors and Shapes
Several species of birch are found in the North Country. While birches, like the species of any other family of deciduous trees, can be distinguished by the shape of their leaves, such clues are lacking in the winter. Instead, we can look at colors and shapes. Aptly named yellow birches have the distinctive pealing bark of all birches, but the bark has a yellowish tinge. I find these birches to be particularly handsome in mid-winter, especially when their bark peels off in wispy strands. Other species have distinctive shapes. If it is tall and thin, with black branches wildly emerging from a single trunk, they you are looking at a grey birch. If it has large white-barked branches creating a wide crown, then you are looking at a white birch or a paper birch.
Yellow Birch, Foss Woods, March 19, 2021
Grey Birch by our pond, February 1, 2021
White Birch next to Pearl Lake Road, April 23, 2020
Photos and text by Carl D. Martland, a founding member of ACT and a long-time resident of Sugar Hill. Quotations from his journals indicate the date of and the situation depicted in each photograph.
Bending Birches
Robert Frost has a poem about a boy climbing up one of the single-stemmed birch trees. As the boy gets higher, his weight pulls the then tree down further and further until it bends right to the ground, allowing him an easy dismount. Winter storms sometimes have the same effect as wet, clinging snow will curve whole rows of birches down to the ground.
Birches in our yard bent over by heavy snow, December 13, 2008
Birch Seeds
Birches produce an immense number of seeds, which form over the summer from dangling clusters of tiny flowers. The seeds still cling to the branches through the end of the winter, and they are finally released in March, a time of the year when the ground is likely to be covered with a crusty snow. When conditions are right, a brisk wind will blow the seeds along like iceboats flying across a frozen lake. The seeds will blow all across a field if there is nothing to stop them. Thoreau describes how birch seeds blowing across snow-covered farm fields only stopped when they came up against a distant rail bank, resulting in the rows of birch trees he observed growing along the rail lines near Walden Pond.
Thousands of birch seeds sitting on the surface of the icy snow in the Back 4, March 9, 2020. With so many seeds, birches are able to establish themselves quickly in any overgrown field.
Birds and Birches
Winter and early spring offer the best chances to see birds in the birches. I first saw Bohemian waxwings when a flock sat puffed up from the cold in a stand of birches on Post Road back in 2009, and I sometimes catch sight of a downy or hairy woodpecker foraging among the branches in the middle of the winter.
A downy woodpecker in a tangle of birch branches in our yard, February 16, 2008
Bohemian Waxwings in birches on Post Road, January 24, 2009
However, I have found yellow-bellied sapsuckers to be the bird that is most attracted to birch trees, especially a couple of what must be particularly sweet-sapped birches at the edge of the Upper Meadow. Once the sap starts running in the spring, the sapsuckers begin to drill their carefully spaced holes in the trunks of their favorite trees. By pecking holes that line up vertically, the sapsucker allows some of the sap to flow through the gaps to reach the crown of the tree, while still creating little flows of sap into and out of each hole. Perhaps sapsuckers like the taste of the sap, but they also feast on the insets that are attracted to the bounty. I watched several generations of sapsuckers do their work on a couple of trees next to the Upper Meadow. The adults begin in the spring; the juveniles join in by August. They don’t mind my taking their picture, so long as I stay ten feet away as I work on my woodpile.
A sapsucker begins pecking a pattern of holes in a birch tree, April 24, 2017
A young sapsucker continues work begun by its elders. August 23, 2011
This activity went on year after year at one particular tree that attracted a great many butterflies, bees, wasps, ants and other insects throughout each summer. That tree finally died about seven years ago, but we have dozens of birches growing in that area, and I miss the activity much more than I miss that tree. And that birch sent up sprouts that I hope will have the same sweet sap that will soon attract new generations of sapsuckers and butterflies.
An eastern comma butterfly sipping sap from the sapsucker’s favorite tree. June 16, 2012
A mourning cloak butterfly sips sap from the same birch tree. August 13, 2011
Do they really have leaves?
When visitors from away first come to New Hampshire, they are happy to see so many birch trees, especially when a white birch’s limbs are outlined against a perfect blue sky. One visitor, who shall remain anonymous (but he knows who he is), thought he knew all about birches, as he had traveled widely throughout New England his entire life. However, on his first summer visit to Sugar Hill, when we were driving along route 3 toward Crawford Notch, he noticed a large, leafy, white-barked tree at the edge of the forest. “What’s that tree?” he asked. I answered, not understanding why he would ask, “A birch, of course.” His response astonished us: “But birches don’t have leaves!” This is a true story. A highly educated New Englander, someone who had spent many a vacation in or near the woods, had only noticed birch trees in the winter and assumed that they were some weird, woody cousin of a cactus!
So, we had to disabuse him of his mistaken opinion of birches, and we can now use this example to explain why this essay has focused so much on birches in the winter. That is when everyone (even this individual) does know a birch, whereas in the summer, some may dismiss the leafy birch as just another tree.
