Thursday, March 19th. 2:20pm. 35°F. Clement Hill, Deering NH.
An old field off Clement Hill is bound by stone walls on all sides — a clear record that this was once open land. Now it's dense with white birch saplings, most under two inches in diameter, packed one to three feet apart.
I stopped at one of the larger saplings to draw it. Snow-white and pink new bark near the top, graying and peeling lower down. Then I noticed one nearby that was under an inch in diameter, brown-red, lenticels running as bright white dashes along the bark. That gap between the two stopped me. When does the bark change from brown-red to white, and why?
The bark is tracking age.
In individuals younger than about five years, paper birch bark is brown-red with white lenticels, identical to the bark you see on every branch, no matter how old the tree gets. The white trunk develops later, establishing fully around eight years of age (Rhoads & Block, n.d.). The transition moves gradually up from the lower trunk, which is why you can find a sapling that reads white at mid-trunk and dark at the base.
The white color is an adaptation to high latitudes, reflecting solar radiation in winter when the sun is at a low angle and temperatures are far below freezing (Mertensia Press, n.d.). Without it, the sun reflecting off snow could warm the thin bark dramatically, and the sharp temperature swing could injure the tissue beneath. The white bark is a functional response to a specific climate.
The branches never make that transition. Bark on young trees and branches remains dark reddish-brown to black, while mature trees develop creamy-white to chalky-white outer bark that separates in flat horizontal layers (Flora of Newfoundland and Labrador, n.d.). The lenticels (pores that allow gas exchange between internal tissue and the atmosphere) that appear as small white dashes on young stems are the same structures that become the long dark horizontal marks on mature white bark, stretched and redistributed by years of growth.
Most of these trees won't make it.
Paper birch is a pioneer species, and seedling mortality is high from the start (Mertensia Press, n.d.). In dense young stands like this one, the pressure increases as the trees grow. What determines survival at this stage is primarily access to light. Paper birch is highly shade-intolerant, and the trees with the largest diameters right now already hold an advantage (Safford et al., 1990).
In the natural succession of species, paper birch usually lasts only one generation and then is replaced by more shade-tolerant species (Safford et al., 1990). The birch colonized this old field because conditions were right — open ground, disturbed soil, full light. But the very canopy they create will eventually shade out their own seedlings and favor the hemlock and maple that can grow beneath them. They are building the forest that will replace them.
How this connects to my work
The tree I drew that afternoon is not a generic birch. It's a specific tree at a specific moment in a specific field that was once cleared and is now in the early stages of becoming something else. The stone walls at the edges are part of that story.
This kind of looking is what drives my studio work. The trail maps embedded in my mixed media pieces carry the same kind of information, a record of where people have moved through the land. What I find in the field ends up in the work: the texture of peeling bark, the line where an old field becomes a young forest, the evidence of change that's been accumulating long before anyone thought to stop and draw it.
If you'd like to practice this kind of observation yourself, I'll be leading nature journaling workshops at the Center for the Arts in New London this spring — May 29 and June 5. See details at https://candrewsart.com/pages/nature-journaling-workshops
References
Flora of Newfoundland and Labrador. (n.d.). Betula papyrifera (white birch). https://newfoundland-labradorflora.ca/flora/dview/?id=9
Mertensia Press. (n.d.). Paper birch (Betula papyrifera). bplant.org. https://bplant.org/plant/220
Rhoads, A. F., & Block, T. A. (n.d.). Betula papyrifera (paper birch). American Gardener. https://americangardener.net/species-of-trees/
Safford, L. O., Bjorkbom, J. C., & Zasada, J. C. (1990). Paper birch. In R. M. Burns & B. H. Honkala (Tech. Coords.), Silvics of North America: Vol. 2. Hardwoods (Agriculture Handbook 654). U.S. Department of Agriculture, Forest Service. https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/betula/papyrifera.htm