Forest Types
Click on the forest type you want to view.
Aspen   Bur Oak   Northern White-Cedar
Balsam Fir   Eastern White Pine   Red (Norway) Pine
>Birch   Hemlock-Yellow Birch   Silver Maple-American Elm
Black Ash-American Elm-Red Maple   Jack Pine   Tamarack
Black Spruce   Maple-Beech-Yellow Birch   White Oak-Black Oak-Northern Red Oak
Black Walnut   Northern Pin Oak    


Birch

| Description | Products and Uses | Site Conditions |
| Regeneration | Immediate Treatments | Pests and Diseases |

Description

Range of paper birch Paper birch forms either small pure stands or mixtures. Quaking and bigtooth aspen and pin cherry are its most common associates. It also may be mixed with yellow birch, red maple, northern red oak, white pine, jack pine, white spruce, and balsam fir. This forest type occurs throughout the northern Lake States (Figure 6-3).

>> Back to top
>> Choose another forest type

Products and Uses

The main uses for paper birch are paper, fuelwood, dowels, and novelty items, but it also is used for lumber and veneer. Birch trees can be tapped in the spring to obtain sap for syrup, wine, beer, or medicinal tonics. Its showy white bark and bright yellow fall foliage make it an attractive landscape tree. Young stands provide an important source of browse for deer and moose. Songbirds feed on its seeds while ruffed grouse and squirrels eat male buds and catkins.

>> Back to top
>> Choose another forest type

Site Conditions

Paper birch may occur in small pure stands.Paper birch is a pioneer tree type that revegetates land disturbed by fire, clearcutting, and other factors. It grows on almost any soil and topographic situation, ranging from steep, rocky outcrops to flat muskegs or bogs. Paper birch tends to grow best on deep, well-drained to moderately well-drained, nutrient rich glacial deposits. It grows poorly on very dry and very wet sites.

>> Back to top
>> Choose another forest type

Regeneration

Paper birch is intolerant of shade and usually is regenerated by clearcutting or shelterwood systems. Although small birches produce vigorous stump sprouts when cut, merchantable-size trees do not sprout well and sprouts are normally of low quality. Natural seeding is the most common source of regeneration. The optimum seedbearing age is 40 to 70 years. In mature stands, good seed crops occur every other year on the average, but some seeds are produced in most areas every year. Its light seeds are dispersed readily by the wind; however, the majority of seeds fall within the stand where they are produced. If a clearcut has to be more than 300 feet wide, leave seed trees throughout the site to get adequate seed dispersal and provide for the survival of seed trees and protection of new seedlings. Remove seed trees within two years after acceptable regeneration.

Paper birch germinate best on mineral soil, so site preparation by disking or burning is recommended. Germination on humus is reduced by about 50 percent, but initial height growth is better on humus than on undisturbed sites, probably because of greater nutrient availability. Germination on undisturbed litter is relatively poor.

Shaded sites produce about twice as many seedlings as full-sun sites, so harvest by narrow, progressive clearcut strips, small patch clearcuts, or a two-cut shelterwood system (especially on hot, dry sites). In a shelterwood system, the first cut should thin the canopy and provide more sunlight to the forest floor. A year later, disk the site to lightly bury the birch seeds, help control competing vegetation, and incorporate organic matter. Disking is especially helpful following a good seed fall. After the stand is sufficiently stocked with seedlings, canopy trees should be clearcut to release the new seedlings.

To establish birch on old field sites, remove the sod, plant bare-root or container-grown seedlings, and protect them from girdling by rodents and browsing by deer.

>> Back to top
>> Choose another forest type

Intermediate Treatments

Young paper birch grows rapidly, but the growth rate declines significantly in old age. The species is short-lived, reaching maturity in 60 to 70 years. It usually lasts only one generation and then is replaced by more shade-tolerant species. Poor sites may be clearcut for firewood every 40 years or converted to another species. When paper birch has an understory of white spruce or balsam fir, the conifers will eventually dominate the standGood sites can be managed for sawlogs on 50-year or longer rotations. On good sites that are clearcut and regenerate to aspen, pin cherry, and paper birch, the faster growing aspen and pin cherry will outgrow and suppress the birch.

Birch often grows in two-story stands. When paper birch has an understory of white spruce or balsam fir, the conifers will eventually dominate the stand, but birch will retain a presence. When paper birch has an understory of northern hardwoods (such as, sugar maple, red maple, basswood, ash, and some oaks), the birch will be replaced by the hardwoods over time. To retain a higher percentage of birch, thin mixed species stands to release the birch. Gradual thinning over time is recommended. The more intense the thinning (the more trees removed), the greater the height and diameter growth response of paper birch. However, heavily thinning a stand that has not previously been thinned may cause many of the remaining trees to die. Stands approaching maturity seldom respond well to thinning.

>> Back to top
>> Choose another forest type

Pests and Diseases

Bronze birch borer is the most serious insect pest of paper birch. Usually it attacks overmature trees or weakened trees. The most serious defoliators are the forest tent caterpillar, birch skeletonizer, birch leafminer, birch leaf-mining sawflies, birch casebearer, and gypsy moth. Defoliation alone seldom kills healthy trees, but it reduces their growth rate and makes birch susceptible to other damaging agents, particularly bronze birch borer.

Birch also is affected by decay-causing fungi, stem cankers that ruin the tree for timber purposes, and root-rotting fungus.

Over-browsing by deer and moose at the seedling stage reduces the amount of dominant birch in regenerating stands or impairs the quality of survivors. Porcupines damage larger trees by feeding on the inner bark and girdling large branches in the crown and upper trunk. The yellow-bellied sapsucker pecks rows of holes through the bark; these become the point of entry for decay organisms and ring shake (separation). Hares and other small mammals may seriously damage planted seedlings. Because paper birch bark is thin and highly flammable, even large trees may be killed by moderate fires.

Paper birch is very susceptible to logging damage during partial harvest treatments using mechanical techniques.

>> Back to top
>> Choose another forest type