TAIGA: CHARACTERISTICS, FLORA, CLIMATE, FAUNA, EXAMPLES - BIOLOGY - 2024

The taiga or boreal forest is a plant formation of trees of the order Coniferae that develops in the northern hemisphere. This plant formation occupies 11% of the emerged lands of the planet.

The strip of taiga or boreal forest is almost continuous, only interrupted by the Atlantic Ocean and the Bering Strait. In some sections it covers 1,000 to 2,000 km wide from north to south. This strip is bounded to the north by the tundra and to the south by mixed forests or prairies. The structure of the taiga is simple, generally with a single layer of trees up to 50 m in height.

Taiga in Canada. Source: peupleloup

In the lower part of the forest (understory) there are few or no plants and the ground is covered with mosses, lichens and ferns. The typical soils are podsols, characterized by being acidic, low in fertility and with little available moisture.

The taiga is the largest forest formation on the planet and spans North America and Eurasia. In North America through Alaska (USA) and all of northern Canada from the Yukon in the west to the Hudson Bay in the east. In Eurasia it goes from northern Europe, Russia, passing the northern Urals to Asia. It extends through Siberia (Russia) to the east, the islands of Sakhalin (Russia) and northern Japan.

The taiga has a low diversity of flora and in the northern latitudes the forests become made up of a single species. The dominant conifer family is Pinaceae, with genera such as Pinus, Larix, Abies, and Picea.

Angiosperms are found in some areas, especially in the southern taiga area, along rivers and in the understory. Among these angiosperms there are species of genera such as Salix and Betula.

The climate is continental boreal, being cold and dry with average temperatures of 11 ºC to 40 ºC in summer and in winter they drop to -30 ºC or -70 ºC. For its part, precipitation rarely exceeds 400 mm per year and in winter the soils are covered with snow.

The fauna is also not very diverse, but in some cases with populations of many individuals. It is represented by large herbivores such as the elk, the reindeer and the deer; and carnivores like the wolf and the lynx.

You can also get some omnivores such as the bear and smaller animals such as rodents and rabbits. Also, there are small carnivores such as the weasel, the marten and the mink.

The fundamental activity linked to the taiga is the timber industry, due to the abundance and quality of the raw material. These regions are also rich in minerals and oil, which is why mining activities are also developed in this plant formation. In addition, various parks and nature reserves have been established throughout the taiga, where tourism is carried out.

The World Wildlife Foundation or World Wildlife Fund (WWF) identifies up to 29 ecoregions belonging to the Taiga or Boreal Forest biome. Of which 18 ecoregions occur in the Nearctic and 11 in the Palearctic.

In some of these regions, zones of national parks have been delimited to conserve this ecosystem. For example, the Canadian Rocky Mountain parks collectively declared a World Heritage Site by UNESCO.

These parks include a representation of the North American taiga, with its characteristic flora and fauna. Another example is the border national parks Oulanka in Finland and Paanajarvi in ​​the Republic of Karelia in Russia.

General characteristics

- The biome and its kingdoms

The taiga constitutes a biome that extends in a wide strip to the north of the entire land mass of the northern hemisphere. It is the most extensive biome of the entire Holartic complex, encompassing the Nearctic kingdom or ecozone (North America) and the Palearctic kingdom or ecozone (Eurasia).

The equivalent to this type of forest in the southern hemisphere are the southern coniferous forests. These forests vary in floristic composition and are much smaller than the taiga.

- Biogeography and vegetation adaptations

The taiga represents the evolution of the vegetation before the latitudinal gradient towards the north in the boreal hemisphere. Towards the Arctic Circle the temperature decreases, as does the precipitation that falls in the form of snow.

The biogeographic transition

Given these conditions, the temperate deciduous forest made up of angiosperms becomes a mixed forest when gymnosperm species appear. Then further north most angiosperms are not adapted to withstand these conditions and most disappear.

Therefore, the landscape becomes dominated by a forest composed of coniferous species (gymnosperms of the order Coniferae). This is because conifers have adaptations that allow them to better withstand these harsh conditions.

This forest is the taiga or boreal forest where lakes, ponds and swamps abound, in depressions left by glacial erosive action.

Adaptations

These adaptations include having acicular (needle-shaped) or scaly leaves, which lose less water through perspiration. In a large part of their extension they are evergreen plants, that is, they keep leaves throughout the year.

Being evergreen is an advantage, as they can photosynthesize year-round and their massive size allows them to store water and nutrients. However, in large areas of Siberia species of the genus Larix dominate which are deciduous conifers (they lose their leaves in autumn).

Further north the conditions become so harsh that no type of tree is capable of developing. Under these conditions, the taiga is replaced by the tundra made up mainly of mosses and lichens.

The fire

Fires are a factor in the ecology of the taiga and natural fires have been determined to occur every 80-90 years. In this sense, the tall crowns of conifers and their thick bark are adaptations that allow them to resist burning.

- Forest structure

The taiga is a forest with a very simple structure, made up of a single layer of trees. They can reach up to 75 m in height to the south and 40 to 50 m to the north.

In most cases there is no understory proper (shrub stratum in the lower part of the forest). Although in the southern part of the taiga there may be understory with Betula middendorffii and Salix kolymensis (angiosperm), as well as Pinus pumila.

Additionally, the soil is covered with lichens (Cladonia spp., Cetraria spp.) And mosses (Sphagnum spp. And other genera). While further north the understory develops in areas near rivers or streams.

- Floor

Due to the low temperature and humidity conditions, the characteristic soil is podzol which is poor in nutrients, largely as a result of permafrost and poor drainage. There is also low humidity available as the water is mostly frozen.

In winter the ground freezes, but in summer it thaws at a much greater depth than it does in the tundra. That is why tree roots can develop in the taiga.

Organic material

Conifers in general provide little organic matter and their resinous leaves acidify the soil. Low temperatures hinder the activity of decomposers such as bacteria, fungi and animals in the soil.

Due to this, poorly transformed organic matter (humus) accumulates on the surface horizon. A high proportion of the soil is needles (needle-shaped coniferous leaves).

Permafrost

It is a permanently frozen layer of soil, although it is not always covered with snow. In the case of the taiga, permafrost is located in the soils located further north.

Permafrost. Source: Boris Radosavljevic

Also, unlike the tundra, the permafrost in the taiga does not form a continuous layer and is found deeper.

Location in the world

The taiga forms a continuous belt in northern North America and Eurasia, with the largest area in central and eastern Russia. It is important to note that boreal forests exist in mountainous areas outside the taiga strip.

These forests originate from orographic causes and not exclusively latitudinal, that is, they are formed in high mountains. There is low precipitation in them in a temperate climate where the temperature decreases with height.

- Nearctic

United States of America

In Alaska, the taiga extends from the Bering Sea (west) to the Richardson Mountains in the Yukon Territory (east). This vegetation formation is bounded by the Brooks Range in the north and the Alaska Range in the south.

Then south through Canada, it stretches down the Pacific coast to northern California.

Canada

The taiga extends across the northern Yukon in high plateaus (1,000 meters above sea level), separated by valleys, then continuing into the interior. It then covers a large area from north to extreme northeast Alberta, northern Saskatchewan, and northwestern Manitoba.

It then continues through much of northern Quebec and most of Labrador, to the Atlantic Ocean (east).

- Palearctic

North Europe

It covers mainly Norway, Sweden, Finland to Russia, including the northern and eastern flanks of the Ural Mountains.

Russia

Siberia is one of the largest unaltered boreal forest or taiga areas in the world. The Russian peninsula of Kamchatka, called "Coniferous Island" by the Russians, represents the easternmost example of Siberian taiga forest.

Taiga in Siberia. Source: Elkwiki

Sakhalin Islands and Northern Japan

Taiga or Boreal forest occurs in the Sakhalin Islands (Russia) and in northern Japan.

Flora

In the broad latitudinal and longitudinal strip that makes up the taiga, the flora varies significantly. Although the common characteristic is the dominance of conifers, the species vary and also the presence or not of some angiosperms.

The flowering plants are mainly shrubs, although there are also some understory areas or trees along rivers.

In the northernmost latitudes the taiga may be made up of a single conifer species and in general the diversity is extremely low.

- Conifers

There are various species of Pinaceae, such as larch (about 13 species of the genus Larix). Among them Larix cajanderi, L. sibirica and L. gmelinii in Siberia and the European larch (Larix decidua).

Other species are Pinus sibirica, Picea obovata and Abies sibirica, which are part of the so-called dark taiga in eastern Siberia. In Canada, north of Alberta, there are forests with black fir (Picea mariana), tamarack (Larix laricina) and white fir (Picea glauca).

- Angiosperms

In Siberia, angiosperm species are found on the banks of rivers, forming gallery forests next to conifers. Among the species that compose them are the poplar (Populus suaveolens), the willow (Salix arbutifolia) and the birch (Betula pendula).

Understory with dwarf birch (Betula sp.), Ericaceous shrubs (Ericaceae) and milkweed (Eriophorum spp.) Are found in the Canadian taiga. Other shrubby understory species are Arctic mulberry (Rubus spp.) And Labrador tea (Rhododendron spp.).

- Ectomycorrhizae

As in many other forests, in the taiga there are extensive symbiotic associations between soil fungi and tree roots. Ectomycorrhizal fungi grow around the roots without penetrating their cells.

There is symbiosis when the roots facilitate the growth of the fungus and this expands the possibilities of the trees to obtain nutrients.

Weather

The taiga or boreal forest is the product of the adaptation of plants to cold and wet winters and hot and dry summers. Summers are short (less than 120 days), with temperatures above 10ºC. In turn, winters are long, lasting 6 months or more.

- Temperature and precipitation

The taiga climate is cold and semi-arid, with annual average temperatures of -3ºC to -8ºC and rainfall of 150-400 mm (in some cases close to 1,000 mm). However, conditions vary from one ecoregion to another within the biome.

Evaporation

In the northern area of ​​the taiga, most of the precipitation falls in summer, but the evaporation rate is low.

Photoperiod

Long days occur during the relatively short growing season, then in winter the days are short.

Limit temperature

The taiga is replaced by the tundra in areas where the maximum monthly temperature does not exceed 10 ºC in any case.

- Nearctic

In the Yukon, the average summer temperature is 11 ºC and the average winter temperature ranges between -16.5 ºC and -19 ºC. While the average annual precipitation is in the range of 225-400 mm, being somewhat higher towards the northeast.

On the Pacific coast of North America, temperatures vary from 35ºC in summer to -50ºC in winter.

- Palearctic

As we move into the Siberian taiga we encounter prolonged and severe winters, with average temperatures in January of approximately -40ºC. In the northeast, in the city of Verkhoyansk, some of the coldest temperatures on the planet occur, down to -70 ºC.

Subsequently, there are short but very warm summers, with average temperatures in July close to 15ºC and up to as high as 40ºC. Annual precipitation ranges from 150-200 mm in central Yakutia to 500-600 mm in the mountains of eastern and southern Yakutia.

Fauna

Possibly the most emblematic species are the reindeer or caribou (Rangifer tarandus) and the bear. About 15 subspecies of the reindeer or caribou have been described and the brown bear (Ursos arctos) extends from North America to Siberia.

- North America

Large herbivores such as elk (Alces alces) and caribou (Rangifer tarandus, American subspecies) are found. Likewise, omnivores such as bears are present, highlighting the black bear (Ursus americanus) or the brown bear (Ursus arctos).

Caribou (Rangifer tarandus). Source: Dean Biggins (US Fish and Wildlife Service)

Of the brown bear, the subspecies horribilis, the grizzly bear and the subspecies middendorffi, the kodiak bear, stand out.

Also, there are species of carnivores such as the wolf (Canis lupus), the glutton (Gulo gulo), the weasel (Mustela spp.) And the mink (Mustela vison). In rivers, the otter (Lontra canadensis) and the beaver (Castor canadensis) are found.

Birds include the red-backed bluebell (Clethrionomys gapperi), the ptarmigan (Lagopus lagopus), and the gray crane (Grus canadensis). Of the birds of prey, the osprey (Pandion haliaetus) and various species of owls (Bubo spp.) Stand out.

- Eurasia

In this area you can find the elk (Alces alces), reindeer (Rangifer tarandus, Eurasian subspecies) and the brown bear (Ursus arctos). Then there is the red squirrel (Scurius vulgaris), the Siberian squirrel (Eutamias sibiricus) and the arctic hare (Lepus timidus).

Carnivores include the lynx (Felis lynx), the red fox (Vulpes vulpes), the Siberian weasel (Mustela sibirica) and the ermine (Mustela erminea).

The most common birds are the hazel (Getrastes bonasia) and the grouse (Tetrao urogallus and T. parvirostris) and the black woodpecker (Dryocopus martius).Among the owls we have the gray owl (Strix nebulosa), the hawk owl (Surnia ulula) and the boreal owl (Aegolius funereus).

Economic activities

- Forestry

Undoubtedly, forestry has historically been relevant in the taiga due to its extensive coniferous forests of enormous proportions. They provide abundant raw material and their exploitation has expanded the tundra in extensive areas of Siberia by up to 40-100 km.

Logging

Taiga is the largest source of wood and pulp in the world thanks to extensive logging based on full zonal pruning. In other words, all the trees in a large quadrant are cut down, which has serious ecological implications.

It is estimated that in Canada alone, about one million hectares of boreal forest or taiga are cut down annually. For its part, the situation in Siberia is not very different, although reliable data are not available.

- Reindeer herding

Especially in the Sami Region (Lapland) a traditional activity is reindeer herding. In the past it was strictly transhumant, where the Sami accompanied herds of reindeer on their annual migration.

- Mining

The boreal region is rich in mineral resources and oil, so the activity of extracting them is important.

Siberia

In this area, the mining of diamonds, gold and tin are economic activities of great importance.

Canada and Alaska

In Canada, the most relevant minerals are uranium, diamonds, nickel and copper. For its part, in Alaska oil exploitation has recently been rebooted.

- Hunting

Given the abundance of large herbivores, hunting has been a traditional activity in the taiga, both in North America and Eurasia.

- Farming

As soils are generally poor in nutrients and acids, they are not suitable for agriculture. However, there are some crops such as cabbage (Brassica oleracea var. Capitata) that can grow rapidly in open areas, reaching large sizes in a short time.

Examples of taigas in the world

Two examples of the 29 ecoregions of the Taiga or Boreal Forest biome identified by the World Wildlife Foundation (WWF) are:

- The Rocky Mountain Parks of Canada

It is a set of four national parks and three Canadian provincial parks located in the Rocky Mountains. They are located in the southwest of Canada in the provinces of Alberta and British Columbia with large areas of boreal forest or taiga.

Rocky Mountain National Park (Canada). Source: Gorgo

The four national parks are Banff, Jasper, Kootenay and Yoho and the provincial ones are Hamber, Mount Assiniboine and Mount Robson. This complex was declared a Natural Heritage of Humanity by UNESCO in 1984 and its main activity is tourism.

Flora

The dominant conifer species are Lodgepole pine (Pinus contorta) and Englemann fir (Picea engelmannii). There is also the Douglas fir (Pseudotsuga menziesii), one of the tallest conifers in the world (up to 75 m).

Among the angiosperms that are distributed in some areas of these parks are the Douglas maple (Acer glabrum) and willows (Salix spp.).

Fauna

This region is part of the habitat of grizzly and black bears, wolves, cougars, lynxes and wolverines. Among the large herbivores live there caribou, elk and various species of deer.

- Oulanka National Park (Finland) and Paanajarvi National Park (Russia)

These are two border national parks that together are home to one of the best preserved taiga areas in the world. The Paanajarvi National Park is to the north of the Russian Republic of Karelia and the Oulanka National Park is on the Finnish side

Flora

Siberian pine (Pinus sibirica), Siberian fir (Abies sibirica) and spruce (Picea obovata) abound in this region. Deciduous conifers such as the Siberian larch (Larix sibirica) are also found.

Angiosperms of the genera Populus (Poplar) and Betula (Birch) are also found.

Fauna

Includes herbivores such as elk and reindeer; as well as brown bears, wolves and the northern lynx.

Activities

They are areas for tourism, including hiking, sailing and sport fishing activities.

References

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