Download Taiga - FOSSweb

Ecoregion: Taiga
Page 1 of 7
Taiga
INTRODUCTION
Taigas are boreal forests, or northern coniferous forests. (Taiga is Russian for "marshy pine
forest.") They stretch across the northern parts of North America, Europe, and Asia. They are
usually located south of tundra and north of temperate deciduous forests and grasslands.
Taigas also extend south in the alpine regions of the Rocky Mountains and the Sierras in the
western United States. The taiga is the largest biome on Earth. It covers about 20 million
hectares (50 million acres) of land, about 17% of Earth's land area.
Ecoregion: Taiga
Page 2 of 7
Art Explosion
There is always abundant water in
taigas, even in areas of dense
trees
Art Explosion
Some sections of taiga have space
between conifer trees, where grasses,
wildflowers, shrubs, and deciduous
trees, such as aspens, grow.
There are two types of taiga: open woodlands with widely spaced trees, and dense forests
whose floor is usually in shade.
ABIOTIC DATA
The taiga is characterized by a cold, harsh climate, low rate of precipitation (snow and rain),
and short growing season. Long, severe winters last up to 6 months, with average
temperatures below freezing. Summers are short, lasting maybe 50 to 100 days without frost.
Art Explosion
Courtesy of Teri Dannenberg
Ecoregion: Taiga
Page 3 of 7
Winters in the taiga are long
and cold. Heavy snowfall is
common.
Melting snow feeds lakes and streams and provides much of
the water spring and summer.
The taiga is very, very cold in the winter. Temperatures vary widely. For example,
Verkhoyansk, Russia, has recorded extremes of –67°C to 32°C (–90°F to 90°F). When the
warmer temperatures of summer come, ice and snow melt. The hours of daylight are much
longer during the summer.
Data from Missouri Botanical Garden
Yearly rainfall in taiga is 38–85 cm (15–33 in.)
Average annual precipitation is 38 to 85 centimeters (15 to 33 inches). Most precipitation
comes in the summer months. Summers are rainy, warm, and humid. The evaporation rates
are low, so the air is usually humid during the summer.
Ecoregion: Taiga
Page 4 of 7
BIOTIC DATA
Many conifer trees (evergreens with needles) grow in the taiga. These include evergreen
spruce, fir, pine, and deciduous larch, or tamarack. In North America, one or two species of fir
and one or two species of spruce are dominant. Across Scandinavia and western Russia the
Scotch pine is a common inhabitant of the taiga.
Some broadleaf deciduous trees and shrubs also grow in the early development of a taiga.
Most common are alder, birch, and aspen. Scientists recognize a 200-year cycle of growth in
taiga forests. The cycle goes between nitrogen-adding aspen forests and nitrogen-using
spruce-fir forests. Aspens quickly grow in newly formed meadows. They provide shelter for the
slower-growing pines. As the aspens age and begin to die, the pines take over as the
dominate tree. This cycle is called forest succession.
Courtesy of U.S. Fish and Wildlife Service
The brown bear, also called grizzly bear, is
one of the largest North American land
mammals.
Art Explosion
An aspen tree grows at the edge of a
dense stand of conifer trees. Notice
the young pine trees nearby.
Ecoregion: Taiga
Page 5 of 7
Taigas are relatively low in animal diversity because of the harsh winters. They have fewer
animal species than tropical or temperate deciduous forests. Some taiga animals cope with
the cold winter environment, but many migrate south to warmer climates during the winter.
Others hibernate until warmer temperatures return.
Fur-bearing predators like the lynx and members of the weasel family (e.g. wolverine, fisher,
pine martin, mink, ermine, and sable) live in taigas. They prey on herbivores like snowshoe or
varying hares, red squirrels, lemmings, and voles.
Courtesy of John and Karen Hollingsworth , U.S.
Fish and Wildlife Service
The gray wolf is a top predator in the taiga
of North America. Humans have moved in
and eliminated wolves as predators that
threaten livestock.
Art Explosion
The rare Siberian tiger is
found in the taiga of
northern Russia and
China. It has been
hunted for its striking fur.
Large herbivores graze in the taiga on deciduous trees and shrubs. These herbivores include
elk and moose. The beaver, the basis for the early North American fur trade, also thrive when
deciduous trees and shrubs are plentiful.
Thousands of bird species migrate to the taiga in the summer to nest. Insect eaters, like the
wood warblers, migrate south after the breeding season. Seed eaters (finches and sparrows)
Ecoregion: Taiga
Page 6 of 7
and omnivores (ravens) are usually year-round residents. During years when food is scarse
birds like the evening grosbeak, pine siskin, and red crossbill leave the taiga in winter and may
be seen at bird feeders as far south as Virginia.
ISSUES
One of the issues that affect the health of the taiga is human development, which reduces
habitat for the plants and animals that live there. Humans kills predators that threaten
livestock. We build roads and power lines, and explore for minerals. The natural succession of
the forest is disrupted when forest fires are suppressed to protect human dwellings.
Many of the taigas of the world are what is called old growth forests. Their large trees are
desirable for the lumber industry. Old growth forests have virtually disappeared in Norway,
Sweden, Finland, and Russia; few are left in North America. The removal of all the large trees
affects the natural rate of succession.
Courtesy of Joe Frobister, Taiga Rescue Network
This part of the Whiskey Jack Forest
Management Area, Ontario, has been clear-cut
for many years. After this type of logging the soil
Ecoregion: Taiga
Page 7 of 7
is exposed to much higher rates of erosion.
Waste products from mining and development may pollute the land and water. Industrial
contaminants from around the world have accumulated in taiga food webs. These
contaminants along with naturally occurring substances, such as some metals and radioactive
material, are transported in by wind and rain.
Climate change is also an issue. Scientists continue to track and compare temperature data to
determine whether it has affected taiga. Warming temperatures can affect habitats, by melting
permafrost areas, raising lake levels, and changing vegetation growth patterns. In addition, the
maximum and minimum temperatures might be higher and the precipitation patterns might
change. Worldwide, precipitation has increased in high latitude areas where the taiga is
located. There is not enough data to determine whether changes have occured.