Tamarack

Products and Uses
Tamarack (eastern larch) is used for pulp, poles, and lumber, although it has relatively minor economic importance. Red squirrel, snowshoe hare, and porcupine are found in tamarack stands. The tamarack is habitat for many songbirds and is critical habitat for the great gray owl and its small mammal prey species.

Growing Conditions
Tamarack is found in pure stands, but more commonly in mixed stands with black spruce, northern white-cedar, black ash, red maple, eastern white pine, or paper birch. Tamarack stands usually are even-aged.

Tamarack commonly grows on peatland where the organic soil or peat is more than 12 inches thick. It occurs on a wide range of peatlands, but is most characteristic of poor swamps where soil water is weakly enriched with mineral nutrients. The best sites are moist, well-drained loamy soils along streams, lakes, or swamps, and mineral soils with a shallow surface layer of organic matter. It grows well on upland sites, but is quickly eliminated by competition from more shade-tolerant species. Tamarack will not survive prolonged flooding.

Regeneration
The regeneration system advised for tamarack is a combination of clearcut and seed-tree with natural seeding. Good seed years occur every 3 to 6 years starting when trees are about 40 years old. The best seedbed is a warm,moist mineral or organic soil with no brush, but a light cover of grass or other herbaceous vegetation. Hummocks of slow-growing sphagnum moss often make a good seedbed. Most seed falls within 200 feet of the seed tree.

Harvest strips should be oriented perpendicular to the wind and may be up to 200 feet wide. After clearcutting the first strip, wait about 10 years or until the area is well stocked with seedlings, then clearcut a second strip adjacent to the first and on the windward side. Again wait until regeneration is established, then use the seed-tree method to cut the remaining strip. The seed-tree cut should leave about ten well-spaced dominant tamaracks per acre. Once the regeneration is established, harvest or kill seed trees.

Range of tamarack.

You may need to prepare the site following a harvest to assure tamarack regeneration. Broadcast burn mixed species stands to remove slash. Since tamarack slash does not burn well, harvest pure tamarack stands by full-tree skidding to remove slash, then treat the brush with herbicides. Alternatively, you could pile and burn the slash or shear or chop the brush.

Tamarack seedlings need abundant light and constant moisture. Seedlings established under a fully stocked stand will not survive beyond the sixth year. Early seedling losses are caused by damping-off fungus, drought, flooding, inadequate light, and snowshoe hares. Given enough light, tamarack is one of the fastest growing conifers on upland sites.

Intermediate Treatments
Thinning is economically feasible only on good sites when the object is to produce poles or sawtimber. If a market exists for small products such as posts or pulpwood, make a commercial thinning as soon as the stand produces these products. Additional periodic thinnings are recommended up to 20 years before the end of the rotation. Each thinning should leave a basal area of 80 to 90 square feet per acre.

Pests
The larch sawfly is a serious insect pest that can kill tamarack after several years of defoliation. Chemical control may be required to manage sawfly populations. There is no effective cultural control for sawfly. Bark beetles can kill tamarack stressed by defoliation or competition in densely stocked stands. Tamarack also is susceptible to root and heart rots. Minimize rots by avoiding damage during intermediate cuttings. Porcupines can cause extensive damage by feeding on the bark of the main stem.