Taiga facts for kids
Quick facts for kids Taiga |
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Jack London Lake in Kolyma, Russia
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The taiga is found throughout the high northern latitudes, between the tundra and the temperate forest, from about 50°N to 70°N, but with considerable regional variation.
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The Taiga (pronounced tie-gah), also called the boreal forest or snow forest, is a huge natural area. It is known for its coniferous forests, which are mostly made up of pines, spruces, and larches. The taiga is the largest land biome on Earth.
In North America, the taiga covers most of inland Canada, Alaska, and parts of the northern United States. In Eurasia, it stretches across much of Sweden, Finland, and a large part of Russia. It also reaches into Norway, Estonia, parts of the Scottish Highlands, some areas of Iceland, northern Kazakhstan, northern Mongolia, and northern Japan (on the island of Hokkaidō).
The types of trees in the taiga change depending on how long the growing season is and how warm the summers get. For example, the taiga in North America is mostly spruce trees. In Scandinavia and Finland, you'll find a mix of spruce, pines, and birch. Russian taiga has spruces, pines, and larches. The Eastern Siberian taiga is a huge forest of larch trees.
The taiga as we know it today is quite new, only about 12,000 years old. It formed after the last Ice Age ended.
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Climate and Location
The taiga covers about 17 million square kilometers (6.6 million square miles) of Earth's land. This is about 11.5% of all land, making it the second largest land biome after deserts. The biggest taiga areas are in Russia and Canada.
Temperatures in the Taiga
After the permanent ice caps and tundra, the taiga has the coldest average yearly temperatures. The average temperature is usually between -5°C and 5°C (23°F and 41°F). Winter temperatures in the northern taiga can be even colder than in the tundra. Some parts of eastern Siberia and Alaska-Yukon have average yearly temperatures as low as -10°C (14°F). The coldest temperatures ever recorded in the Northern Hemisphere were in the taiga of northeastern Russia.
The taiga has a subarctic climate with very big temperature differences between seasons. A typical winter day might be -20°C (-4°F), while an average summer day could be 18°C (64°F). The long, cold winter is the most important feature of this climate. Summers are short (1 to 3 months) but usually warm and humid. Winters are long (5 to 7 months) with temperatures below freezing.
In Siberian taiga, the average temperature of the coldest month is between -6°C and -50°C (21°F and -58°F). In some areas, the ground is always frozen, which is called permafrost. This makes it hard for trees with deep roots to grow.
Growing Season in the Taiga
The growing season is when plants in the taiga start to grow. It's usually a bit longer than the official summer because taiga plants can start growing at lower temperatures. Some experts say the growing season typically lasts about 130 days.
In Canada and Scandinavia, the growing season is often measured by how long the average daily temperature is 5°C (41°F) or more. In Canada's Taiga Plains, the growing season lasts from 80 to 150 days. In the Taiga Shield, it's 100 to 140 days.
The longest growing seasons are in coastal areas with warmer ocean influences. Here, the growing season can be 145 to 180 days. The shortest growing season is at the northern edge of the taiga, where it meets the tundra. Here, the growing season is only 50 to 70 days.
Because the taiga is at high latitudes, the sun doesn't rise very high in the sky. This means less sunlight reaches the ground. However, in summer, the days are very long, with the sun staying up for nearly 20 hours, or even 24 hours in some places. In winter, days are very short, with only about 6 hours of daylight, or none at all, depending on how far north you are. Areas inside the Arctic Circle have midnight sun in summer and polar night in winter.
Rain, Snow, and Fog
The taiga gets a relatively small amount of precipitation each year, usually between 200 and 750 mm (8 to 30 inches). Some areas can get up to 1,000 mm (39 inches). Most of this comes as rain in the summer, but it also gets a lot of snow or fog. Snow can stay on the ground for up to nine months in the northern parts of the taiga.
Fog is common, especially in low areas after the Arctic seas melt. This fog can block sunlight from reaching plants, even during the long summer days. Because there isn't much evaporation for most of the year, the amount of precipitation is enough to support the thick forests. This is why the taiga has so much plant life compared to dry areas like the Steppe, where water evaporates quickly.
The taiga usually grows south of where the average July temperature is 10°C (50°F). In some places, it can grow as far north as the 9°C (48°F) July line. The southern edge of the taiga is more varied. It can turn into forest steppe if there's very little rain, or it can extend further south where there's more rain.
In warmer areas, the taiga has more types of trees, including warmth-loving species like Korean pine and Jezo spruce. It gradually blends into mixed temperate forests or even temperate rainforests near the Pacific Ocean coasts.
How Glaciers Shaped the Taiga
Much of the taiga in Europe and North America (except Alaska) was covered by huge glaciers a long time ago. As these glaciers melted and moved back, they left behind dips in the land. These dips filled with water, creating the many lakes and bogs (like muskeg soil) that you can find throughout the taiga today.
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The taiga near Verkhoyansk, Russia, has the coldest winters in the Northern Hemisphere.
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Lakes are common in the taiga. This is Helvetinjärvi National Park, Finland.
Taiga Soils
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The soil in the taiga is usually young and doesn't have many nutrients. It's not as rich as the deep, dark soil found in temperate forests. The cold climate slows down how quickly soil forms and how easily plants can use its nutrients. Also, there aren't many deciduous trees (which drop lots of leaves) or grazing animals (which add manure) to enrich the soil.
Fallen leaves and moss can stay on the forest floor for a long time in the cool, moist climate. This means they don't add much organic material to the soil. Acids from evergreen needles also wash nutrients out of the soil, creating a type of soil called spodosol or podzol. The acidic forest floor often only has lichens and some mosses growing on it. In open areas or where there are more deciduous trees, you'll find more herbs and berries, and the soil is deeper.
Plants of the Taiga
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Since North America and Eurasia were once connected by a land bridge, many animal and plant species were able to spread across both areas. However, some plants are different in different regions. Taigas also have some small-leaved deciduous trees, like birch, alder, willow, and poplar. These trees mostly grow in areas that don't have the most extreme winter weather.
The Dahurian larch can handle the coldest winters in the Northern Hemisphere, found in eastern Siberia. The very southern parts of the taiga might have trees like oak, maple, elm, and lime mixed in with the conifers. There's often a gradual change into a temperate, mixed forest, like the Eastern forest–boreal transition in eastern Canada. In drier inland areas, boreal forests can turn into temperate grassland.
There are two main types of taiga:
- The closed canopy forest is in the southern part. It has many trees growing close together and a mossy ground. In open spots, you'll find shrubs and wildflowers like fireweed and lupine.
- The lichen woodland or sparse taiga has trees that are farther apart and a ground covered in lichen. This type is common in the northernmost taiga. Here, the trees are not only spread out but often stunted.
In Canada, Scandinavia, and Finland, the boreal forest is often divided into three subzones:
- The high boreal (northern taiga zone)
- The middle boreal (closed forest)
- The southern boreal is a closed forest with some scattered temperate, deciduous trees among the conifers. This area has the longest and warmest growing season. In some regions, like Scandinavia, this area is used for farming.
The boreal forest is home to many types of berries. Some berries, like wild strawberry and partridgeberry, grow only in the southern and middle closed-boreal forest. Others, like cranberry and cloudberry, grow in most taiga areas. Some berries, such as bilberry, bunchberry, and lingonberry, can grow in both the taiga and the southern tundra.
The taiga forests are mostly coniferous, dominated by larch, spruce, fir, and pine. The mix of trees changes with geography and climate. For example, the Eastern Canadian forests have mostly balsam fir, while further north, the Eastern Canadian Shield taiga has mostly black spruce and tamarack larch.
Evergreen trees in the taiga (spruce, fir, and pine) have special ways to survive the harsh winters. Larch trees, which can handle extreme cold, actually lose their needles in winter. Taiga trees usually have shallow roots to deal with the thin soils. Many trees also change their internal chemistry to become more resistant to freezing. The narrow, cone shape of northern conifers and their drooping branches help them shed snow.
Because the sun is low in the sky for most of the year, it's hard for plants to make energy from photosynthesis. Pine, spruce, and fir trees keep their leaves all year. This lets them photosynthesize with their old leaves in late winter and spring when there's good light but it's too cold for new growth. Their evergreen needles also help them save water, and their dark green color helps them absorb more sunlight. Even though there's enough precipitation, the ground freezes in winter, so tree roots can't absorb water. This means evergreens can suffer from dryness in late winter.
While conifers dominate the taiga, some broadleaf trees like birch, aspen, willow, and rowan also grow there. Many smaller plants, such as ferns, grow closer to the ground. Regular wildfires (every 20 to 200 years) clear out the tree tops, letting sunlight reach the forest floor and encouraging new growth. For some species, fires are a necessary part of their life cycle. For example, some jack pine cones only open to release their seeds after a fire, spreading them onto the newly cleared ground. Certain types of fungi, like morels, also do this. Grasses grow wherever they can find sunlight. Mosses and lichens thrive on the damp ground and on tree trunks. Compared to other biomes, the taiga has fewer types of plants.
Coniferous trees are the main plants in the taiga. There are only a few species, mainly from four groups: the evergreen spruce, fir, and pine, and the deciduous larch. In North America, one or two species of fir and spruce are most common. In Scandinavia and western Russia, the Scots pine is a common taiga tree. The taiga in the Russian Far East and Mongolia is mostly larch. Two deciduous trees, birch and Populus tremula, are mixed throughout southern Siberia.
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Conifer cones and morels after a fire in a boreal forest.
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Moss (Ptilium crista-castrensis) covers the floor of the taiga.
Animals of the Taiga
The boreal forest/taiga supports a relatively small number of animals. These animals are very specialized and adapted to the harsh climate. Canada's boreal forest has 85 types of mammals, 130 types of fish, and about 32,000 types of insects. Insects are very important for pollinating plants, breaking down dead material, and as food for other animals. Many nesting birds, rodents, and small meat-eating mammals eat insects in the summer.
The cold winters and short summers make the taiga a difficult place for reptiles and amphibians. These animals need the environment to control their body temperatures. There are only a few species in the boreal forest, including the red-sided garter snake, common European adder, blue-spotted salamander, wood frog, and American toad. Most of them hibernate underground in winter.
Fish in the taiga must be able to live in very cold water and survive under ice. Some fish species found here include Alaska blackfish, northern pike, walleye, lake whitefish, and various types of grayling.
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The taiga is home to many large plant-eating mammals, such as Alces alces (moose) and different types of Rangifer tarandus (reindeer in Eurasia; caribou in North America). Some southern parts of the boreal forest also have other Cervidae species like the maral and roe deer. While usually found in polar regions, some muskoxen live in the taiga of Russia's Far East and North America. The Amur-Kamchatka region of Russia also has snow sheep and wild boar. The largest animal in the taiga is the wood bison of northern Canada/Alaska.
Small mammals in the taiga include rodents like the beaver, squirrel, chipmunk, lemming, and vole. There are also a few lagomorph species, such as the pika and snowshoe hare. These animals have special ways to survive the cold winters. Some larger mammals, like bears, eat a lot in summer to gain weight, then hibernate in winter. Other animals have thick fur or feathers to keep warm.
Meat-eating mammals in the taiga must be able to travel long distances to find food, or they can eat plants or other food sources. Some predators in the taiga include the Canada lynx, Eurasian lynx, stoat, sable, wolverine, fisher, timber wolf, coyote, red fox, grizzly bear, American black bear, and the rare Siberian tiger.
More than 300 species of birds build their nests in the taiga. Birds like the Siberian thrush and white-throated sparrow migrate to this habitat in summer. They take advantage of the long summer days and the many insects found around the bogs and lakes. Out of 300 bird species that spend summer in the taiga, only about 30 stay for the winter. These are usually birds that eat dead animals or large raptors that can catch live mammals, such as the golden eagle, great gray owl, and raven. Other birds that stay for winter eat seeds, like various species of grouse and crossbills.
Wildfires in the Taiga
Fire is one of the most important things that shapes the boreal forest. It's the main way old stands of trees are replaced with new ones. The way fires happen in an ecosystem is called its fire regime. This includes:
- The type and strength of the fire (like crown fires that burn tree tops).
- The typical size of important fires.
- How often fires happen in a specific area.
The average time it takes for an area equal to the whole ecosystem to burn is called its fire rotation or fire cycle. However, some areas might not burn for a very long time, while others might burn more often.
Most fires in the boreal forest are very intense crown fires or severe ground fires. They are very large, often burning more than 10,000 hectares (24,710 acres), and sometimes even over 400,000 hectares (988,420 acres). These fires kill all the trees in a stand. Fire rotations in drier parts of western Canada and Alaska average 50–100 years. In the wetter climates of eastern Canada, they can be 200 years or more. Fires also happen less often near the tree line in the subarctic spruce-lichen woodlands.
Fires are deeply connected to how plants grow in the landscape. In the east, fires help black spruce, paper birch, and jack pine grow more than balsam fir. In the west, they help aspen, jack pine, black spruce, and birch grow more than white spruce. Scientists often find charcoal under the forest floor, which tells them about past fires. Most boreal forest stands are less than 100 years old. Only in areas that have avoided burning are there white spruce stands older than 250 years.
Many boreal plant species have special features that help them survive fires. For example, seven of the ten most common trees in the boreal forest—jack pine, lodgepole pine, aspen, balsam poplar, paper birch, tamarack, and black spruce—are "pioneers." This means they are good at quickly growing in open areas after a fire. White spruce also has some pioneering abilities, but it's not as good as black spruce and pines at spreading seeds all year. Only balsam fir and alpine fir don't seem to be well-adapted to reproduce after fire.
The oldest forests in the northwest boreal region, some over 300 years old, are pure stands of white spruce growing on moist floodplains. Here, fires happen much less often than on nearby higher lands dominated by pine, black spruce, and aspen. Without fire, the boreal forest would become more uniform. The long-lived white spruce would gradually replace pine, aspen, balsam poplar, and birch, and perhaps even black spruce, except in the peatlands.
Climate Change and the Taiga
In the last part of the 1900s, the taiga experienced some of the biggest temperature increases on Earth. Winter temperatures have gone up more than summer temperatures. The number of extremely cold days (like -20°C to -40°C) has decreased. This helps insects that damage trees survive better. In Fairbanks, Alaska, the frost-free season has grown from 60-90 days to about 120 days over a century.
Scientists think that boreal environments have only a few stable states: a treeless tundra/steppe, a dense forest, or an open woodland. So, ongoing climate change could turn some taiga forests into woodlands or treeless steppes. But it could also turn tundra areas into woodlands or forests as they get warmer.
Several studies in the early 2010s found that there was a lot of tree loss in western Canadian boreal forests since the 1960s due to drought. This trend was not as strong in the eastern forests. However, a 2016 study found no overall trend in Canadian boreal forests between 1950 and 2012.
A 2018 study using satellite images confirmed a drying trend and forest loss in western Canadian forests. It also found some greening in the wetter east. Later research found that even where the total amount of plant material didn't change, there was a shift towards deciduous broad-leaved trees that can handle drought better.
While most studies have been in Canada, similar trends have been seen in other countries. Warmer summers have caused water stress and reduced tree growth in dry areas of the southern boreal forest in central Alaska and parts of far eastern Russia. In Siberia, the taiga is changing from mostly larch trees (which shed needles) to evergreen conifers because of the warming climate. This change could speed up warming even more, as evergreen trees absorb more of the sun's rays.
Scientists are also predicting future forest trends. A 2018 study of seven common tree species in Eastern Canadian forests found that 2°C warming alone increases their growth by about 13%. However, water availability is much more important than temperature. Further warming up to 4°C would cause big declines unless there's also more rain.
A 2021 paper projected that boreal forests are much more affected by climate change than other forest types in Canada. It predicted that most eastern Canadian boreal forests would reach a "tipping point" around 2080 under a high emissions scenario. Another 2021 study projected that under a "moderate" scenario, boreal forests worldwide would see a 15% increase in plant material by the end of the century. However, this would be more than canceled out by a 41% decline in tropical forests.
A 2022 study on tipping points in the climate system identified two related tipping points for the taiga:
- The death of trees at its southern edge, causing it to turn into grassland.
- The opposite process in the north, where rapid warming of the nearby tundra turns it into taiga.
Both processes are already happening. However, they might not become unstoppable until global warming reaches about 4°C (7.2°F). Once the right level of warming is met, either process would take at least 40–50 years to finish, and likely a century or more.
If the southern taiga dies off, it would release about 52 billion tons of carbon. However, the overall effect on global temperature would be a slight cooling (about 0.18°C globally). This is because snow-covered ground reflects more sunlight than forests. Similarly, if the boreal forest expands into the tundra, it would capture about 6 billion tons of carbon. But it would also cause a slight global warming effect (about 0.14°C globally). This is also because snow-covered ground reflects more sunlight than forests.
Other Threats to the Taiga
Human Activities
Some large cities in the taiga biome include Murmansk, Arkhangelsk, Yakutsk, Anchorage, Yellowknife, Tromsø, Luleå, and Oulu.
Large parts of Siberia's taiga have been cut down for lumber since the Soviet Union ended. Before, the forest was protected. But with the collapse of the Soviet Union, it became easier to sell trees to other countries. Loggers have been cutting down Russian taiga evergreen trees to sell.
Insects
In recent years, there have been outbreaks of insect pests that destroy forests. These include the spruce-bark beetle in Yukon and Alaska, the mountain pine beetle in British Columbia, and the spruce budworm. These insects can cause widespread damage to the trees.
Pollution
Scientists have studied how sulfur dioxide (a type of air pollution) affects taiga trees. Even small amounts of sulfur dioxide can reduce how well plants make food through photosynthesis. Deciduous trees (like aspen and willow) were affected more quickly than conifers (like spruce and pine).
Acid rain, caused by pollution, has also been linked to damage to plants and reduced forest growth. However, some studies on young white spruce trees showed no significant reduction in growth from simulated acid rain, although the trees did show signs of injury.
Protecting the Taiga
The taiga stores enormous amounts of carbon, more than all the world's temperate and tropical forests combined. Much of this carbon is in wetlands and peatland. Wildfires could release a lot of this carbon into the atmosphere. Managing fires is a cheap way to prevent carbon from being released.
Some countries are talking about protecting parts of the taiga. This would mean no logging, mining, oil and gas production, or other types of development. In 2008, two Canadian provinces, Ontario and Quebec, promised to discuss protecting at least half of their northern boreal forest. They said it would take decades to plan, working with Indigenous and local communities. If completed, these would be some of the largest protected areas in the world. However, not much action has been taken since then.
For example, in February 2010, the Canadian government created limited protection for 13,000 square kilometers (5,019 square miles) of boreal forest. This included a new park reserve in the Mealy Mountains and a provincial park along the Eagle River.
Natural Disturbances
One big area of research is how fires affect the taiga and how they help the lichen woodland grow. Fires caused by lightning are the main thing that determines what plants grow on the forest floor. This is because the plants that grow after a fire affect how tree seedlings sprout and how nutrients are recycled in the long term.
Large, damaging fires happen about every 70 to 100 years. To understand this ecosystem, we need to know how plants grow back after a fire. Trees, shrubs, and lichens all recover from fire damage by growing new parts or by new seeds spreading. Seeds that have fallen and are buried don't help much in regrowing a species. Lichens reappear because of different conditions and light/nutrient availability in each small area.
Scientists have developed a theory that after a fire, plants can grow back in four ways:
- Self-replacement: The same dominant species grows back.
- Species-dominance relay: Different tree species try to become dominant one after another.
- Species replacement: Fires happen often enough to stop one species from becoming dominant.
- Gap-Phase Self-Replacement: This is rare. Surviving species grow into the empty spaces left after a fire kills another species.
The path taken after a fire depends on how well the land can support trees and how often fires happen. Fire frequency plays a big role in shaping the lower forest line of the lichen woodland taiga.
Some scientists believe that the spruce-moss forest ecosystem changed into the lichen woodland biome because of two strong disturbances: large fires and attacks by the spruce budworm. The spruce budworm is a very harmful insect to spruce trees in the southern taiga.
Images for kids
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The taiga in the river valley near Verkhoyansk, Russia, at 67°N, experiences the coldest winter temperatures in the northern hemisphere, but the extreme continentality of the climate gives an average daily high of 22 °C (72 °F) in July
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Lakes and other water bodies are common in the taiga. The Helvetinjärvi National Park, Finland, is situated in the closed canopy taiga (mid-boreal to south-boreal) with mean annual temperature of 4 °C (39 °F).
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Conifer cones and morels after fire in a boreal forest.
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Moss (Ptilium crista-castrensis) cover on the floor of taiga
See also
In Spanish: Taiga para niños
