Also referred to as the ‘boreal forest’, the taiga biome spans across North America and Eurasia in the northern hemisphere of the planet. It is typically characterized by the presence of coniferous forests which are adapted to the climatic conditions prevailing in this region. Even though the taiga biome only covers 11 percent of the total surface area of the planet, it happens to be the largest of the terrestrial biomes on the Earth. Approximately 27 percent of the world’s forest cover is attributed to the taiga biome. Even though it is the largest of the terrestrial biomes on the planet, you don’t get to see much of diversity when it comes to taiga animals and plants – as compared to other biomes of the world.
Taiga Biome: An Overview
In a broad sense, the taiga biome is categorized into two types – ‘closed canopy forests’ wherein tall, closely spaced trees form a canopy and ‘sparse taiga’ wherein the trees are far-spaced as compared to the trees in closed canopy forest. The term ‘boreal forest’ is more often used in Canada wherein the taiga is divided into three sub-zones – high boreal/northern boreal, middle boreal and southern boreal. Given below are more of such interesting facts about the taiga biome with special reference to its geographical extent, climate, soil, as well as biodiversity in terms of flora and fauna.
In terms of geographical extent, the taiga biome spans across the continent of North America and Eurasia – with a major chunk of the same lying in Canada and Russia. Other than Canada, this biome crosses over into the United States of America – i.e. Alaska and northern portions of the continental United States to be precise, in North America. In Eurasia – on the other hand, the characteristic coniferous forests are found in Sweden, Finland, Norway, Russia, Kazakhstan, Mongolia and Japan, with Russia having the major share of the same. If the location of taiga biome in terms of coordinates is to be determined, it would be 50°N to 70°N i.e. the higher latitudes of the northern hemisphere. The cold climate that happens to be a characteristic attribute of the taiga can be attributed to this very latitudinal extent of this biome.
The taiga biome boasts of being second only to the tundra biome in terms of lowest annual average temperature. On a typical winter day, the average temperature in this biome is approximately – 4ºF, while the same on a typical summer day is approximately 64.4ºF. Similarly, the boreal forests experience around 200-750 mm of annual precipitation – in form of rain in summer and snow in winter, which is quite low as compared to various other parts of the world. The average biodiversity that this biome speaks of can be attributed to the climatic conditions prevailing in this biome which make it difficult for plants and animal species to survive here. The few plants and animals which do inhabit these coniferous forests resort to adaptations to survive the harsh climate.
Soil and Vegetation:
There is a little bit of confusion when it comes to growing season in the taiga biome, with some sources suggesting that the growing season here is somewhere around 120-150 days, while others suggesting that it is 50-100 frost free days. As a result of the cold climate prevailing here, the rate at which plant matter decomposes is very low and hence the soil in taiga tends to be poor in terms of nutrients as compared to the temperate deciduous forests in the neighborhood. The vegetation here is predominantly dominated by evergreen species such as spruce, fir, and pine, and deciduous species such as larch. In fact, some of the world’s oldest trees are found in the forests of taiga, with the bristlecone spines found in California being the oldest of them all.
Plant Adaptations in Taiga:
Even though the climatic conditions in taiga are harsh, soil is poor in terms of nutrition and the region is prone to wildfires, the plants here have developed some interesting adaptations which help them survive these conditions with immense ease. The thick bark that the trees in this region sport is one of the most prominent plant adaptations in tundra, which helps them make sure that they don’t fall prey to wildfires which happen to be a common occurrence in this part of the world. Other adaptations in taiga plants include narrow conical shape to shed snow, needle shaped leaves to minimize water loss as a result of transpiration, and dark green colored leaves to make the most of whatever little amount of sunlight is available.
Animals: As in any other biome of the world, the abiotic conditions play a crucial role in determining what animals live in the taiga biome. As many as 85 species of mammals – including the lynx cats, moose, reindeer, American black bear, grizzly bear, foxes, etc., are found in the taiga biome. Add to it the 300 odd species of birds and 32,000 species of insects found here, and the biodiversity of this region becomes all the more impressive. The list of bird species found in taiga include predatory birds, carrion feeding raptors as well as ground-nesting birds. Some noteworthy species include the Golden Eagle, Rough-legged Buzzard, White-throated Sparrow, Black-throated Green Warbler, Raven, Siberian Thrush, and other species of grouse, crossbills, eagles, owls, etc. At the same time, rodents like beavers, hares, voles, squirrels, etc., are also found here in abundance. As reptiles and amphibians rely on the climatic conditions to regulate their body temperature, it becomes quite difficult for them to survive the cold, lengthy winters and short summers of the taiga biome.
Animal Adaptations in Taiga
As in case of plants, even taiga animals rely on adaptation skills for survival against the harsh conditions. Hibernation and migration during the winter season happen to be the most prominent of the taiga biome animals adaptations. Mammalian species – such as the bears, found in taiga eat during the summer season, store food in their body in form of fats, and go into hibernation with the onset of winter. Species like the reindeer migrate down south most often in search of food during the cold season. Of the 300 species of birds found here, only 30 stay back in this region in winter, while all the others migrate thousands of miles in search of food and shelter. Similarly, animals like the lynx cats as well as some bear species have a thick layer of fur on their body to protect them from harsh cold.
Over the last few years, climate change and human encroachment has affected the taiga biome to a great extent. As the average temperature in this region continues to soar, it is resulting in shorter winters which – in turn, provide apt conditions for growth of insects which damage the trees. At the same time, large-scale logging – which has come up as a major commercial activity in this region, has resulted in deforestation and loss of habitat for several species, thus bringing them on to the verge of extinction. Even though it is not as diverse as the rainforest biome, there is no doubt about the fact that the taiga biome is important for the overall ecosystem of the planet.
THE EAST SIBERIAN TAIGA
is vast, spanning over 20 degrees of latitude and 50 degrees of longitude. It represents one of the most extensive natural forests left in the world. Larch forests dominate the region
as they are able to withstand the extreme climate conditions.
The climate is strongly continental, reaching its extremes in the region’s northeast. The anticyclone eferencesweather dominates most of the year. The summer is very hot (up to +40° Celsius (C)) and winter is bitterly cold (down to -62°C in Central Yakutia), but snow cover is only moderate or thin. The average annual temperature
is below freezing. All this leads to the preservation of permafrost, which is a major factor for the distribution of vegetation and many environmental processes. Annual precipitation ranges from 400 to 600 millimeters (mm) in the western part, gradually decreasing to 200 mm eastward.
The flora and fauna of the eastern Siberian taiga is significantly richer
than those of the western Siberian taiga. There are many endemics at the species and genus levels of various taxa. Central Yakutia can be considered one of the endemism centers in Siberia. The flora of eastern Siberia (including the mountains
) consists of more than 2,300 species. Flora of vascular plants of Central Siberian plateau include 1010 species. More than 650 species have been found in Olekminskij Zapovednik.
The fauna of the eastern Siberian taiga is considerably older than that of the western Siberia taiga. The Enisey River is an important zoogeographical border because many taiga animal species occur only to its east.
In relation to the western Siberia taiga, the eastern Siberian taiga has a much denser population
of hoofed animals, such as: Alces alces, Capreolus capreolus, Sus scrofa
and Cervus elaphus
. The total number of vertebrate species is high. In Krasnoyarsky Krai, which constitutes only part of the ecoregion
, there are 4 species of amphibians
, 2 species of reptiles
, 203 species of birds and about 80 mammals. The Enisey River and its tributaries contain 42 species of fish. There are 11 nationally threatened vertebrate species, including Aquila chrysaetos, Pandion haliaetus, Falco peregrinus, Ciconia nigra
and Grus monacha
The eastern Siberian taiga still preserves vast pristine habitats
, probably one of the most extensive in the world. Only a fraction of them are located in protected areas.
These include the zapovedniks of Stolby, Olekminskij, Tugusskij, Tsentralno-sibirskij (Eniseisko-Stolbovoy uchastok), Lenskie Stolby National Park and numerous nature monuments. Nevertheless, the existing network of protected areas is not sufficient for such an extensive region. The diversity of the taiga ecosystem
is not completely represented, and protected areas are located far apart.
TYPES AND SEVERITY OF THREATS
The main threats are widespread forest fires, intensive clear-cuts
in the central and southern taiga subzones and poaching
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