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Boreal Shield

Greening Sudbury

The greening of Sudbury
Sudbury is the site of Canada’s largest mining and smelting complex, the processor of one of the world’s most valuable deposits of nickel. Situated in the heart of a 1,600-square kilometres mineral-rich geological basin — possibly created by meteorite impact — the city developed after the construction of the CPR mainline in the 1880s. By the early 20th century, it had become the major mining centre.

But the impact of its activities on the local environment was devastating. By the 1970s, decades of mining and smelting had left soils on local sites so acidic that nothing would grow. Some 10,000 hectares had been reduced to desolation. With Laurentian University and Inco Ltd., Sudbury embarked on land reclamation through reforestation. Reclamation involves adding limestone to neutralize the soil, followed by fertilizer and special seed mix to increase nutrient levels. Once vegetation is established, the site is planted with pine seedlings. Much of the work, undertaken in some cases by student volunteers, is done by hand. Inco grows and supplies thousands of pine seedlings. The firm uses the warm and protective conditions of abandoned mine shafts to grow seedlings, which are brought to the surface every spring. As a result of success in land reclamation, Sudbury is now a world centre for environmental science issues relating to mining.


Damaging deluge The animation begins with a diagram showing a three-quarter drawing of a partially wooded slope, which also has a lake and a river. As the narration proceeds, industrial buildings appear, which emit gases from smokestacks. Labels and arrows show how the emissions mix with atmospheric clouds and water and form acid rain and snow, and how acids leach through soils into groundwater.

Content (Narration)
Acid precipitation has long been a problem in the Boreal Shield. Sulfur dioxide and nitrogen oxide are by-products of smelting and refining certain metal ores and of fossil fuel combustion for transportation, power generation, and heating.

These emissions combine with atmospheric water vapour to produce corrosive nitric and sulfuric acid. The acid may then fall as rain, fog, or snow, or spread as gases and particles. Winds can carry emissions far from where they originated.

These emissions are particularly problematic in Ontario and Quebec, where rock, water, and soil are unable to neutralize acid. Instead, acid can leach through the soil and into the water table. The fallout damages forests, makes soil too acidic for organic growth, and devastates lakes and streams.


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Quiz :

What are the best sources of wood pulp for paper manufacturing?

maple and pine
poplar and cedar
spruce and balsam fir