What natural vegation and soil does the boreal shield have?

Answer 1

During the last ice age, which ended 10 000 years ago, the Shield was repeatedly scoured by advancing glaciers. While in retreat, they blanketed much of the landscape with coarse till released

by torrential meltwater streams. Glaciation also had an important influence on the nature of today's soils, having scraped away much of the preglacial cover, often right down to bedrock. Not only are most soils here relatively thin, they are also high in acidity, low in nutrient availability, and cool.

Organic soils underlying the expansive wetlands of this area further restrict plant growth by being oxygen poor and notoriously soggy. Although all of these qualities put severe restrictions on agriculture, the soils of the Boreal Shield are generally well suited for the growth of coniferous trees, as shown by the vast evergreen forests that now blanket much of this ecozone.

Cool temperatures, a short growing season, frequent forest fires, and acidic soils are among the

many challenges faced by plant life in this ecozone. In spite of this, almost 85% of the ecozone is

forest, of which 70% is considered productive for timber. The forest is dominated by a few highly

adaptable tree species, such as black spruce, white spruce, jack pine, and balsam fir. Black spruce,

the most common species, yields high-quality wood pulp and is therefore a prime species for

Canada's growing paper industry.

Farther south there is a higher proportion of broadleaf trees, such as paper birch, trembling aspen,

and balsam poplar, as well as other conifers, such as white, red, and jack pine. In southeastern parts

of the ecozone, species characteristic of more temperate climates are common, including yellow

birch, sugar maple, black ash, and eastern white cedar.

Throughout the Boreal Shield, these forests are mixed with innumerable bogs, fens, marshes, and

other wetlands. Covering nearly 20% of the ecozone, these wetlands are among its most diverse

and biologically productive ecosystems.