Boreal forests and climate change
Boreal forests, found in the Subarctic regions of North America, Europe, and Asia, are the largest land biome on Earth, characterized by coniferous trees such as spruces, pines, and firs. These forests are ecologically significant, acting as major carbon sinks that play a critical role in the global carbon cycle, while also contributing to the cultural identity of many Indigenous and local communities, particularly in Canada and Siberia. The climatic conditions of boreal forests include short, cool summers and long, harsh winters, with precipitation primarily occurring as snow.
However, boreal forests face significant threats from climate change and resource extraction activities, such as logging and oil and gas development. Increased temperatures and changing precipitation patterns may intensify natural disturbances like wildfires and insect infestations, potentially disrupting the delicate balance of these ecosystems. While warmer conditions could enhance tree growth, the overall impact of climate change remains concerning. Conservation measures are being implemented in various regions, especially in Canada, to protect these forests from further degradation. Understanding the complex dynamics of boreal forests amid climate change is essential for their preservation and the health of the global environment.
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Boreal forests and climate change
DEFINITION: Coniferous forests within the Subarctic land biome, existing in a nearly continuous band throughout the northern regions of North America, Europe, and Asia
Boreal forests play an important role in the cultural identities of people living in many parts of the world, particularly Canada and Siberia. These forests, which store large amounts of carbon and thus are a crucial element in the global carbon cycle, are threatened by resource development and climate change.
Boreal forests, or taiga, make up the world’s largest land biome, covering vast parts of the Northern Hemisphere near 50 degrees of latitude and forming an ecologically sensitive between the Arctic and the temperate forest. Boreal forests extend through most of inland Canada, parts of Scandinavia, Russia (particularly Siberia), northern Mongolia and parts of central Asia, and northern Japan. They extend southward to parts of the Scottish highlands and the northern continental United States. Boreal forests are characterized by the dominance of conifers, such as firs, pines, spruces, hemlocks, and larches, and by a mean annual temperature between −5 and 5 degrees Celsius (23 and 41 degrees Fahrenheit).
Boreal forests typically have short, cool summers and long, cold winters. Precipitation can vary from 20 to 200 centimeters (approximately 8 to 79 inches) per year and falls mostly as snow. Because there is little evaporation, the ground remains moist during the summer growing season. Owing to the high latitude, summer days are very long and winter days are very short.
In addition to conifers, mosses and lichens form an important part of the boreal forest ecosystem. Some broad-leaved deciduous trees, such as birch, aspen, and willow, are also present in boreal forests.
While low in when compared with other biomes, boreal forests are home to a variety of animals as well as plants, many of them endangered. Animals found in boreal forests include reindeer or caribou; carnivores such as bear, wolverine, lynx, fox, weasel, and wolf; and more than three hundred species of birds.
Boreal forests rely on natural cycles of fire and insect damage followed by new tree growth; in North American boreal forests, these cycles are typically seventy to one hundred years long. Boreal forests store large amounts of carbon, perhaps more than the world’s tropical and temperate forests combined.
The primary threats to boreal forests are logging, development of oil and natural gas reserves, and climate change. Large areas of Siberian and Canadian boreal forests have been logged, often by clear-cutting. Substantial reserves of oil and natural gas exist under boreal forests in Alaska, Canada, and Russia. As world oil demand rose and technologies for working in very cold climates improved, these reserves became possible candidates for development. It is unclear whether slow-growing boreal forests would be able to recover from the environmental impacts that accompany oil and natural gas extraction.
Although boreal forests require fire and insect infestations for their natural cycle of death and renewal, the increased frequency of both that is associated with climate change may have negative effects. Also, as temperatures rise, deciduous broad-leaved trees can outcompete conifers in southern regions.
Several countries have enacted measures to protect boreal forests through improved management of resource development and conservation. For example, Canadian logging companies are generally required to replant or encourage natural forest renewal, and in 2010 the Canadian federal government enlarged the areas of boreal forests to be protected from development. About 94 percent of all boreal forest in Canada were on public land as of 2024, allowing the Canadian government to implement land-use policies to protect the forests.
According to a 2023 study published in the Proceedings of the National Academy of Sciences, climate change has had a negative impact on Canada’s boreal forests in the form of wildfires, increased insect outbreaks, and drought; however, the study also found that warmer temperatures also allow the forests trees to grow about 20 percent faster, possibility mitigating some of the harmful aspects of climate change.
Bibliography
Elliot-Fisk, Deborah L. “The Taiga and Boreal Forest.” In North American Terrestrial Vegetation, edited by Michael G. Barbour and William Dwight Billings. New York: Cambridge University Press, 2000.
Hari, Pertti, and Liisa Kulmala, eds. Boreal Forest and Climate Change. Berlin: Springer, 2008.
Henry, J. David. Canada’s Boreal Forest. Washington, D.C.: Smithsonian Institution Press, 2001.
Wang, Jiejie, Anthony R. Taylor, and Loïc D’Orangeville. "Warming-Induced Tree Growth May Help Offset Increasing Disturbance Across the Canadian Boreal Forest." Proceedings of the National Academy of Sciences, vol. 120, no. 2, 3 Jan. 2023, doi.org/10.1073/pnas.2212780120. Accessed 16 July 2024.