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Northern Coniferous Forest

The conifer forests of the North, also known as the boreal forest, stretch in a vast unbroken arc from Newfoundland and Labrador south to New England, west to the Great Lakes and central Canada, and up to the Yukon and central Alaska. Just to the north is the tundra, where the ground is permanently frozen. In the Northern Coniferous Forest bedrock is close to the surface, and soils are generally thin and highly acidic. In the northern reaches of this region, the bedrock is limestone, but the soils are still acidic due to the buildup of organic matter. Within the trackless northern forests, there are several vegetation associations.

Taiga

The most extensive association is the taiga or boreal forest, which lies farthest to the north, and blends with the tundra. Taiga is a Russian word for conifer forest. Here, the trees are small in stature and the ground is often soggy. In low areas, bogs and muskegs are found, permanent wetlands dominated by ericaceous shrubs and herbs. The farther south you go, the larger the trees become. White spruce and pines dominate the drier sites above the water table. In saturated soils, black spruce, larch, and white cedar are common. In disturbed sites, quaking aspen and alders (Alnus species) hold the soil as young conifers become established. The mossy ground layer is carpeted with dense stands of shade-tolerant wildflowers such as twinflower (Linnaea borealis) and bunchberry (Cornus canadensis).

Mixed Coniferous/Hardwood Forest

In the southern reaches of the province, conifers form a mixed association with deciduous trees. The mixed coniferous/hardwood forest association is more diverse than the boreal zone. Along with the near monoculture of spruce, larch, and quaking aspen of the north grow balsam fir, birches, maples, and poplars (Populus species) that can survive the milder winters. The ground layer of the forest is more diverse as well. Orchids, twisted stalks and mandarins (Streptopus species), asters, and evergreen groundcovers such as partridgeberry (Mitchella repens) and hepaticas (Hepatica species) are common. Most gardeners live in this southern portion of the floristic province.

The Boreal Challenge

Gardening in the boreal region is a challenge. The growing season is short, and the shade is often dense. Their tall trunks and narrow canopies enable conifers to grow close together, effectively blocking most direct rays from the sun. As an adaptation to year-round shade, plants such as hepaticas (Hepatica species), partridgeberry (Mitchella repens), and bunchberry (Cornus canadensis) bring out the heavy artillery - thick, evergreen leaves. Their persistent leaves enable these plants to photosynthesize all season long.

Another challenge to gardeners is that the evergreen needles of the dominant trees in boreal forests are effective barriers to rain. Much of the precipitation evaporates directly from the tree canopy, without ever reaching the soil. The evergreen leaves of hepatica and other herbaceous species are leathery to help the plants resist drought.

Bloom in coniferous forests is geared less to sunlight patterns than to temperature and moisture. Soil thaws and warms slowly in shade. As the snow melts, marsh marigold (Caltha palustris) and other early plants bloom, but the main show is between late spring and summer. Deciduous plants such as orchids, violets (Viola species), and bellwort (Uvularia grandiflora) flower first, followed by the evergreen species like bunchberry. A few asters bloom in the autumn before winter's snow blankets the ground, resetting the clock and beginning the cycle anew.