Quaking Aspen

From BWCAWiki

Aspens are trees of the willow family and comprise a section of the poplar genus, Populus sect. Populus. There are six species in the section, with only one of them native to the Boundary Waters Canoe Area Wilderness:

• Populus tremuloides - Quaking, Trembling or American Aspen (northern & western North America)

Quaking aspens are native to cold regions with cool summers, in the north of North America, extending south only at high altitudes in mountains. They are medium-sized deciduous trees reaching 15-25 m tall, exceptionally to 30 m.

Description

Aspens are distinguished by their nearly round leaves on mature trees, 4-12 cm diameter with irregular rounded teeth. They are carried on strongly flattened leaf stems, which enable the leaves to twist and flutter in the slightest of breezes. The juvenile leaves on young seedlings and root sprouts differ markedly from the adult leaves, nearly triangular, showing here the typical leaf shape of most other poplars; they are also often much larger, 10-20 cm long. The five typical aspens are distinguished from each other by leaf size and the size and spacing of the teeth on the adult leaves.

Reproduction

Aspens typically grow in large colonies derived from a single seedling, and spreading by means of root suckers; new stems in the colony may appear at up to 30-40 m from the parent tree. Each tree only lives for 40-150 years above ground, but the root system of the colony is long-lived, in some cases for many thousands of years, sending up new trunks as the older trunks die off above ground. One such colony in Utah, given the nickname of "Pando", is claimed to be 80,000 years old, making it possibly the oldest living colony. Some aspen colonies become very large with time, spreading about a metre per year, eventually covering many hectares. They are able to survive intense forest fires as the roots are below the heat of the fire, with new sprouts growing after the fire is out.

Ecology

Aspens are important food plants for the larvae of some butterflies and moths.