Bog Birch

Bog birch

Bog Birch (Betula pumila)

Background:

The four birches native to Prince Edward Island range from the common to the very rare. As with other families, each member has a distinct place in our Island ecosystem, though there may be two or even three species growing in the same area. Each has its own tolerance for sun and moisture. Growth rates, life span and wood quality also differ widely.

 

Identification:

All birches have toothed leaves that are simple and alternate. When young, it is difficult to distinguish species by bark, since they all have reddish-brown, shiny bark with white spots (lenticels). As you might expect, bog birch is a small tree, rather more like a shrub. It rarely grows more than 3 m (10 ft.) high and on all specimens I have encountered the bark remains like that of any juvenile birch.

Habitat:

Bog birch lives up to its name, being found in acidic, boggy areas. It needs full sun to thrive and is usually surrounded by plants with similar tolerances –willowrose, Labrador tea, larch and black spruce.

Propagation:

Birch seed is grouped in cone-like strobiles and can be collected by hand from shorter trees. Pick when the strobiles are fully developed and break apart quite readily. On taller trees, it is often possible to find strobiles under trees after a strong windstorm. Birch seed is easy to clean. Simply rub the strobiles over a screen or strainer that will allow the seed to drop through and catch the bracts. Seeds need a cold period before planting, so they can be stored in a fridge with a small amount of damp peat or potting soil. In the spring, sprinkle the mixture on top of a seedbed, but do not cover with soil. Birch seed needs light for germination but doesn’t like to dry out. A slatted table (providing 50% shade) and regular light mistings provide optimal conditions for germination. My one attempt with bog birch was unsuccessful, probably due to an insufficient cold period, but I will be trying again to reproduce this rare plant.

Wildlife uses:

Birch seed is an important food source for many winter birds, including American goldfinch, pine siskin, northern junco, blue jay, and the chickadees and sparrows. Birches regularly produce heavy crops of seed and larger trees can be quite important to local populations of birds. During the Christmas bird counts, especially if the surface of the snow is crusty, you can see dozens of small birds chasing after birch seed that has been scattered by the wind. While the seed is important for wildlife (including small mammals), the trees are used in many other ways. Ruffed grouse can often be found in birch trees during the winter eating the buds, and snowshoe hares browse the twigs. In spring, birch flowers attract many insects, which in turn attract large numbers of migrating warblers.

Birches can also be important nesting sites for red-tailed hawks and vireos, as well as cavity nesting birds such as 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 the nest and den linings. In addition, yellow-bellied sapsuckers regularly drill into birches to allow sap to run out and attract ants. As you can see just from this partial list of wildlife uses, the birches are important to a wide variety of species.

Conservation:

Bog birch is one of our rarest plants and all efforts should be made to conserve this species. Many of the bogs where it may have historically been found have suffered serious habitat disturbance. It can still be found on the remnants of the Miscouche bog and a few other areas and these sites should be protected from further development. It is not inconceivable to see this species being extirpated from the province without strong government intervention.

Historical Information:

Although we cannot go back in time to see the forests of PEI at the time of settlement by Europeans, we can acquire a reasonable picture by analysis of the written records of that time. This has been achieved by Dr. Doug Sobey in his work “Early Descriptions of the Forests of Prince Edward Island”. An interesting note is that early settlers and many people up to the twentieth century, believed that the yellow birch was actually two separate species. Younger yellow birch were easily identified, but the the old and large yellow birch have a distinctive black bark and loses much of it’s younger looks. This lead many people to believe that “Black birch” was actually a separate species of birch. The recorders of the time indicate that the birches were among the island’s more important trees. Many records have “black birch” listed and it occurs more often than yellow birch, which indicates the forests were in a mature old-growth forest state. Generally, it was described as common throughout the island. Grey birch was rarely mentioned, as it was seen of little use and not worthy of note. Some areas of the island are mentioned as having a predominance of birch. Yellow birch was described in many sites, including along Richmond Bay, Trout River, New London, Point Prim, Pinette River, Wood Islands, Mount Stewart, and a number of other areas. White birch was recorded as being located in a few local areas, but was prominent in the area of the great fires that ravaged the north-east of the island during the French period. Yellow (black) birch was described as being the largest of all the decidious trees of the island, with such terms as “very large” and “a great size” being used. Individual records include a yellow birch trunk of three to four feet in diameter with sometimes as much as six feet. White birch was recorded to be of a much smaller size than yellow birch, however there are records of large individual white birch trees being selected by Mi’kmaq for canoes capable of carrying many people.

Upcoming Events

Jul
3
Mon
9:00 am Becoming a Naturalist Week 1
Becoming a Naturalist Week 1
Jul 3 @ 9:00 am – Jul 7 @ 3:00 pm
This camp builds on the camper’s ability to encounter and describe the natural world. They will use journals, collecting equipment, and take part in many fun activities that will expand their understanding of how to
Jul
10
Mon
9:00 am Young Ecologists Week 1
Young Ecologists Week 1
Jul 10 @ 9:00 am – Jul 14 @ 3:00 pm
This camp will begin to introduce the campers to the amazing complexity of our native Acadian forests. They will dissect owl pellets, take part in forest restoration planning and plantings and develop their understanding of
Jul
15
Sat
2:00 pm Forest Restoration Workshop
Forest Restoration Workshop
Jul 15 @ 2:00 pm – 4:00 pm
Forest Restoration Workshop @ Macphail Woods Nature Centre | Vernon Bridge | Prince Edward Island | Canada
The Forest Restoration workshop offers alternatives to clear-cuts and plantations, and other ideas on how to improve the health of Island forests. It starts with a presentation in the Nature Centre and then participants will