Red Alder

(Alnus rubra)

Featured image

Radiant and colorful

Broadly acclaimed for a variety of high-value wood products, alder also fixes nitrogen from the atmosphere and is an excellent recycler of nutrients. Native Americans used the bark to treat many problems from insect bites to lymphatic disorders. They also used the bark to dye fishing nets to make them less visible underwater.

Range

Red alder is common along stream courses in the Coast Range and Cascades below 2,000 feet elevation. On moist sites it will grow across the landscape. It is an important riparian species for habitat.

Character

This fast-growing, pioneer species is a medium broadleaf tree up to 120 feet tall. It has a short life span but is well suited to the dynamic environment near streams. The bark is mottled, ashy-gray and smooth, often covered with moss. Leaves are broadleaf ovals that turn yellow in the fall. Male flowers, known as catkins, produce pollen in the early spring. Female flowers, or strobiles, develop into reddish dangling cone-like dry fruit in autumn.

Understory

Often shade-tolerant conifers such as western hemlock and Sitka spruce are found scattered under the canopy of the alder. Salmonberry is one of the most common shrubs associated with an alder forest. Elderberry and blackberry are also found, making it an ideal place for many mammals and birds.

Climate

The red alder loves the climate of the West Coast and are found west of the Cascades where it is moist, humid and temperate.

Management

It is recommended that the alder is harvested rather than left to die out naturally, as Douglas-fir, western red cedar and more red alder can be planted in harvested areas, allowing for regrowth over the following decades. Many alder stands that are left undisturbed will convert to salmonberry brush fields as the alder dies.


Source: Oregon Forest Resource Institute: Red Alder