Anatomy of a Boreal Forest

WHAT IS A BOREAL FOREST?

Boreal forest, or taiga, is the largest land-based biome on Earth. This is the type of forest that covers more than 60% of Alberta’s land, and the type of forest Alberta’s forest sector works in. Alberta’s natural regions include boreal forest, the foothills, parkland, grassland and Canadian shield – forests are present in the foothills and parkland regions as well.

The boreal forest biome circles the planet’s northern hemisphere like a crown, stretching across Canada, Siberia, and Scandinavia. Since it makes up a very large proportion of Earth’s forests overall, this immense tract of boreal forest is socially, economically, and environmentally important to the whole world.

UNIQUE CHARACTERISTICS

Different types of forest all have their own distinctive features.

A boreal forest is very different from a coastal forest you might find in BC, for example, or a tropical rainforest in Brazil. Boreal forests are tough, cold-weather forests, located in areas with short growing seasons, long, dry winters, and acidic, nutrient-poor soil. The tree canopy of a mature boreal forest is dense, letting little sunlight through to the understory. Other important types of ecosystems, such as wetlands, also exist within and are sheltered by boreal forests.

One of the most distinctive features of a boreal forest is its relatively short, repeating lifecycle. Compared to other types of forest, this kind of forest grows, dies, and regenerates at a faster rate, and its ecosystem is adapted to that cycle of frequent destruction and renewal. Natural disturbances like fire and insect infestations play a part in maintaining that cycle, and sustainable harvesting mimics those natural processes.

TREES

Evergreen coniferous trees, which release their seeds through cones, are well adapted to the cold and tend to dominate boreal forests.

Some Alberta tree species, like lodgepole pine and jack pine, have serotinous cones – this means their cones are protected by a waxy coating, and only release seeds their seeds when they’re exposed to brief, intense heat from forest fires.

They exist alongside some deciduous species, like trembling aspen and birch, that have evolved to survive the cold as well. Some coniferous species native to the boreal forest have adapted to release their seeds specifically in response to fire, reflecting the boreal forest’s pattern of frequent destruction and regrowth.

The tree species native to Alberta’s forests have a maximum lifespan of about 150 years under ideal conditions, and historical fire patterns show that most Alberta forests would burn every 50-100 years without human intervention. Mature boreal forests might look like they’ve been standing for centuries, but they haven’t – Alberta doesn’t really have “old growth” forests like some sections of coastal forest in BC. Instead, we have forests with relatively short maximum lifespans that have fallen and regrown again and again, creating the illusion of an ancient, undisturbed wilderness.

WILDLIFE

More than 300 bird species use Canadian boreal forests as their nesting grounds during their breeding season.

Many more species that nest and breed further north pass through the boreal region on their way, and some types of birds – like owls, woodpeckers, ravens, and finches – live in the boreal forest year round. More than half the bird species in North America depend on these forests at least sometime during the year.

Many of Canada’s most iconic animals can be found in Alberta’s boreal forests. Moose, bears, deer, wolves, woodland caribou, Canada lynx, and elk all make homes there, along with smaller animals like snowshoe hares, lemmings and beavers. There are about 85 mammal species that live in the boreal forest. Thousands of insect species are part of our forests too, playing important roles as pollinators and food sources within the forest ecosystem.

Rivers, ponds, streams, and lakes within our forests are home for fish species that can tolerate the long, cold winters. This includes many smaller fish species, like minnows, and some larger ones including several types of trout. These fish species are sensitive to disturbances in their habitat, which is one reason the forest industry needs to take such care in maintaining the integrity of water ecosystems in our forests.

WETLANDS

Almost a quarter of the world’s wetlands are in Canada, and many of those are in boreal forests like Alberta’s.

Wetlands are some of the most powerful carbon-storing ecosystems we have, as decaying plants submerge below the surface and the carbon released in that process stays out of the air. They also filter fresh water and meet the unique needs of many wildlife species, including migratory water birds like ducks and larger animals like woodland caribou.

Wetlands are interconnected with the rest of the forest ecosystem. They’re a key link in the flow of the water and nutrients that the forest needs to thrive, and they help prevent flooding by absorbing run-off and precipitation. Fens, which are nutrient-rich wetlands with heavy peat deposits and slow-moving water, are the most prevalent type of wetland in the western boreal forest.