The boreal forest, also known as taiga (transliterated from Russian), exists mostly between 50 and 70 degrees N latitude and is primarily coniferous, mostly comprised of pine, spruce and larch. It covers roughly 11% of the planet, and is considered to be the largest terrestrial biome. Most boreal forest exists now where ice sheets were in the last glaciation.
Regions of boreal forest.
Average annual temperatures range from -5 to 5 deg C (23 to 41 deg F). Trees and other vegetation are well adapted to these cold temperatures, and revive for the growing season before summer, to gain maximum advantage from the longer days, even despite the still-cold temperatures. Precipitation across these regions is generally low.
The carbon cycle.
In recent years, as carbon emissions caps have become a political topic, accounting for the CO2 uptake of these forests has become controversial. Average annual temperatures across the region have increased, leading to species change, toward species better able to tolerate warmer temperatures. Wildfires have also become more prevalent, as have insects, parasites and diseases. The result is declining capability of the northern forest to absorb and process carbon dioxide. They are currently estimated to remove more than 350 Gt C (gigatons of carbon) per year, but that amount is projected to decline in coming years.
Tomorrow: carbon accounting.
Be well!
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