Boreal Vegetation
Introduction
The boreal forest covers 14.7 million square kilometers, 11% of the earth's terrestrial surface (Margolis). It extends across Alaska and Canada in North American and the Scandinavian Peninsula and northern Russia in Europe and Asia, where it is called the taiga (Henry).
The boreal forest is dominated by coniferous evergreens. Some species are circumpolar; some are specific to one hemisphere. A rule of thumb is, the lower (in height) the species, the wider the range. Tree species are confined to one hemisphere. (As an example, black spruce and white spruce are dominant in North America, but these two species are not found in Europe or Asia.) Approximately 70% of the circumpolar species are Arctic species. 75% of the species unique to North America are boreal species (Larsen).
The
boreal forest covers 1/3 of terrestrial Canada, approximately 4 million
sq. km. It plays an important role in the Canadian economy.
In 1996, forest products from the boreal forest region accounted for
$55
billion and 830,000 jobs. In 1985, $115 million of freshwater
fish
were harvested from Canadian lakes, "mostly from the taiga". (Henry)
Worldwide, the boreal forests are not only
important
economically, they are a "carbon sink". The carbon stored in
boreal
forest biomass accounts of 1/2 of the carbon which results from fossil
fuel combustion and is not accumulated in the atmosphere (Margolis).
The Mackenzie Gas Project is a proposed 1300-km. pipeline which will transport natural gas from fields in the Mackenzie Delta to existing pipelines in Alberta, Canada.
These web pages focus on the boreal forest of the Northwest Territory and northern Alberta and the potential impacts a disturbance such as a pipeline might have.
photo from USGS
Contents
Boreal
Forest Biomes
Open Coniferous Forest, Closed Coniferous Forest,
Deciduous-Coniferous Forest What are the characteristics of
these biomes? How do they differ?
Adaptations
to Climate
How have the plants of the boreal forest adapted to climatic conditions?
Wetlands
Bogs! How do bogs form? Why? What is the role of sphagnum
moss?
Fire
Why is the role of fire? How are the forests adapted to fire?
Succession
Aspen, spruce and "old growth"?
Above
(Atmosphere) and Below (Permafrost)
Climate influences vegetation, but vegetation also has an effect on
climate - and on the amount and depth of permafrost. How?
The
Pipeline as a Disturbance
What does a pipeline entail? How does it compare to other
disturbances?
Pipeline-Vegetation
Issues
How will the pipeline impact vegetation? What are some of the
issues?
Regeneration
Will vegetation regenerate after a disturbance? What practices
enhance regeneration?
written by: Joan Rech
last updated 12/08/03