Thursday, October 29, 2009


Nature Watch
By Susan Benson,
CNHM Director of Education

Autumn Gold

The autumn gold colors of the tamaracks that greeted us this past week have been a joy to see. Although the tamarack tree resembles other evergreens, it is actually a deciduous conifer, so it sheds its needles every fall. It grows in cold, wet, poorly drained sites such as swamps, sphagnum bogs, and occasionally in upland soils. The pale green needles are soft, about one inch long, and grow in brush-like tufts along the twig. In the fall, just before the needles drop, they turn a beautiful golden color, providing a striking contrast to the last of the fall foliage.

Tamaracks have some other interesting characteristics. Their life expectancy is up to 180 years. They are cold tolerant and able to survive temperatures down to at least -85 Fahrenheit. The tree casts a light shade, so tends to have a dense undergrowth of shrubs with speckled alder, willows, red-osier dogwood, Labrador-tea, bog-rosemary, leatherleaf, or blueberries growing beneath. Because of its intolerance to shade, tamarack stands are usually even-aged.

The life cycle of a tamarack is appealing. In a bog, a tamarack tree is usually the pioneer, the first tree to establish itself in the sphagnum moss mat floating over the water.
It leafs off in the early spring before the ground has thawed, and takes four to six weeks for the needles to develop. In open areas, tamaracks can begin seed production when they are fifteen years old, but most pine cone crops come from trees that are 50 to 150 year old trees. One tree can produce as many as 20,000 cones in a good year, which can happen every three to six years. They can also produce root sprouts up to thirty feet from the parent tree. In mid-October the needles begin to change color. By the end of October, most of the seeds have dispersed, primarily through wind, but also by red squirrels forgotten caches. Most wind-dispersed seeds fall within two tree heights of the parent tree.

Animals interact closely with the tamarack tree. It is estimated that due to the consumption of seed off the ground, half of the crop is destroyed. Red squirrels cut and cache the cones for later eating. Mice, voles and shrews consume large numbers of seeds off the ground. Pine siskins and crossbills eat the seeds. By the time bacteria and fungi have “fed” off the seeds, it is thought that only about four to five percent of the seed that reaches the ground actually germinates. Additionally, snowshoe hares feed on twigs and bark, porcupines on inner bark. Ospreys sometimes choose to rest in dead tamarack, as do bald eagles on occasion.

Tamarack trees have an interesting natural and human history. Following the last ice age, it was one of the earliest species, along with spruce, to follow the retreating ice northward. Native Americans used the roots for cordage, the wood for arrow shafts, and the bark for medicine. Roots were used for sewing canoe edges. Early Americans used soft needles for stuffing pillows and mattresses. The wood was used widely for ship building, for timbers, planking, and to join the ribs to the deck timbers. The inner bark was used to treat melancholy, and the bark contains tannin that has been used for tanning leather.

Tamaracks seem to be sitting on the fence when it comes to deciding whether to be categorized as a conifer or a deciduous hardwood, and certainly cannot be called an “evergreen.” Regardless, we continue to benefit from their autumn beauty.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at to learn more about exhibits and programs.

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