Taiga Biome
Geographic Range
• The taiga biome is restricted to areas
between fifty degrees latitude north and the
Arctic Circle. Though restricted by latitude,
the taiga is not restricted by longitude.
• The taiga biome exists in both the eastern
and western hemispheres, the largest of
which being in Russia.
• Other areas in which the taiga is prominent
are Siberia, Alaska, Canada, and Scandinavia.
Temperature
• In the winter, temperatures in the taiga vary.
On average, the temperature is anywhere
between between -65 and 30 degrees.
• In the summer, temperatures range from 27 to
70 degrees.
• On average, the temperature is below freezing
in the taiga year round.
Climate
• Wind from the Arctic Circle blows downward,
bringing bitterly cold temperatures.
• Temperatures decrease drastically on cold nights
with little to no cloud coverage.
• Winter is the longest season and lasts between six
and seven months.
• Fall is the shortest season.
Precipitation
• The average annual amount of snowfall in the
taiga is 20-40 inches.
• On average, the taiga experiences 10-20 inches
of rainfall.
• The average annual amount of overall
precipitation is 40 inches.
Soil Types
• Due to the extremely cold temperature in the taiga,
there is a layer of permafrost, or permanently frozen
soil underground.
• A layer of bedrock is also present, and the bedrock
combined with the permafrost prevents water from
draining from the first few layers of soil.
• The presence of the excess water creates muskegs.
Muskegs are shallow bogs that look like solid ground
and are often covered by short grasses, trees, and
mosses.
Life Forms/Sample
Populations
Animals
• Moose
• Lynx
• Bears
• Wolverines
• Foxes
• Squirrels
• Wolves
Plants
• Coniferous trees
• Pines trees
• Oaks trees
• Maple trees
• Elm trees
The taiga is home of the needle leaf forest regions.
Abiotic Factors
• Extreme weather
• Hard soil types keeping water from draining
• Extreme snowfall
Keystone Species
• Wolves are a keystone species.
– When wolves are killed off, the species wolves
keep in check are allowed to reproduce freely,
and resources become scarce.
Adaptations
• Animals like moose and wolves have thick coats
for warmth.
• Hares camouflage themselves to hide from
predators, and their coats change from brown to
white in the winter and vice versa.
• Bears hibernate in the winter.
• Owls have sharp predatory claws for hunting in
the snow.
Adaptations
Continued
• Moose have long legs for walking through the
snow.
• Birds migrate to warmer areas during cold
winter months.
• Plants have smooth waxy coatings to help
retain water and shed ice.
Examples of Symbiosis
• Mutualistic
– Moss growing on a tree. The tree houses the moss, and
the moss protects the bark on the tree
• Parasiticism
– Grape vines become hosts for aphids and die.
• Commensalism
– Fungi feeds off of dead trees. The trees are dead and
therefore not harmed.
Population Density
and Growth
• Density
–Independent limiting factors: Weather- cold
temperatures, and excessive precipitation
–Dependent limiting factors: Competition
for resources, like food.
Carbon and Nitrogen
Cycles
Carbon Cycle
Nitrogen Cycle
Carbon Cycle
•
In the beginning of the carbon cycle, carbon gets taken in in the form of carbon
dioxide by producers who need carbon for photosynthesis. This carbon then gets
turned into sugar inside the plant (photosynthesis). Then, the producer either dies
and decomposes, or the plant gets eaten by a consumer, and the carbon gets passed
up the food chain. When the plant or final consumer to eat an organism containing
the same carbon as the plant dies, decomposers break down the remains and release
the carbon back into the atmosphere through cellular respiration. Sometimes, carbon
goes directly to the soil after the plant or animal dies, and in that case, the carbon is
stored as a fossil fuel and released through combustion. Either way, the carbon ends
up back in the atmosphere, ready to go through the carbon cycle again. Without
carbon, the organisms could not survive because there would be no sugars for energy.
The carbon cycle ensures that carbon is used and reused efficiently. Producers take in
carbon for photosynthesis. The carbon gets turned into sugars, and the grass and
carbon are consumed by a moose. The moose is then consumed by a wolf, which
transfers the carbon up the food chain. Eventually, the wolf dies, and decomposers
break down the carcass and release the carbon back into the atmosphere.
Nitrogen Cycle
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Nitrogen is used in chlorophyll, amino acids, and nucleic acid. Without these, photosynthesis could not occur, and
organisms would not be able to live. Every organism needs nucleic and amino acids. The nitrogen cycle ensures
the most efficient use of the nitrogen and recycles it to allow for the survival of living organisms. The nitrogen
cycle occurs in several stages.
In the first step, fixation, nitrogen is turned into ammonium by nitrogen-fixing bacteria. These bacteria often live
in the roots of plants, most commonly legumes, such as peas and beans.
Bacteria then must alter the nitrogen yet again by turning the new ammonium into nitrate. Plants are able to
utilize nitrate, unlike nitrogen and ammonium (nitrification). For the nitrate to be used in chlorophyll, nucleic
acids, and amino acids, the nitrate must be absorbed through the roots of the plant.
The plant then uses the nitrogen, or the plant is eaten by a consumer, which passes on the nitrogen (assimilation).
Decomposers and bacteria transform the nitrogen in dead organisms back into ammonium so that the nitrate can
be reused (ammonification).
Bacteria push nitrogen not currently being used in the soil into the atmosphere (denitrificatin).
Atmospheric nitrogen would be taken in from the soil into the roots of Trifolium pratense (a legume) which is
where nitrogen-fixing bacteria live. These bacteria would turn the nitrogen into ammonium, and then they would
turn the ammonium into nitrate. The nitrate would be absorbed by the plant roots and used within the plant cell's.
Either the nitrogen remains within the cell, or it is transferred to a consumer that ate the plant, like a moose. After
the moose or the plant dies, bacteria and fungi, like lichen, turn the nitrogen back into ammonia to be recycled
back into the nitrogen cycle. Finally, bacteria in the soil push excess unused nitrogen from the soil back into the
atmosphere.
Factors
Biotic
Abiotic
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Biotic factors are living organisms that
have an impact on their environment.
Such organisms are moose, bears,
wolves, spruce trees, evergreen trees,
and many more. Each organisms plays
an important role in the food and
energy web as a producer, consumer, or
decomposer. The plant life also has a
huge impact on the biome and the
survival of other organisms. Trees are a
source of food and shelter, but they
also block sunlight and prevent some
other plants from being able to grow.
Every organism plays its part in the food
web and dynamic in the taiga.
Abiotic factors are nonliving and inanimate objects
that also have an impact on the dynamic of life in
the ecosystem. Some abiotic factors that play a
large role in the taiga are sunlight, large amounts of
precipitation, and soil types. Sunlight is one of the
major components of photosynthesis in producers.
Without sunlight, plants are unable to produce
glucose, and the consumers in the area will
compete over limited resources or starve. The taiga
has limited sunlight in some areas due to the dense
growth of trees that allows little light to reach the
ground. Precipitation is another major abiotic
factor. The taiga experiences over 20-40 inches of
snowfall every year. This gargantuan amount of
snowfall not only kills plants beneath the surface of
the snow, but also kills the consumers that starve to
death. The surface of the taiga is dangerous, but
what's below the surface can be just as dangerous.
The layer of permafrost not only interferes with
plant root systems, but it also causes flooding that
kills vegetation when the snow melts in the spring.
Symbiosis
• Symbiosis is a close association relationship between at least two
organisms. Sometimes symbiosis benefits both organisms, and sometimes
it doesn't.
• Mutualistic- In mutualistic symbiosis, both organisms benefit from the
relationship. One example of this relationship in the taiga is moss growing
on a tree. Not only is the moss housed and protected by the tree, but the
tree's bark is shielded by the moss growing on it.
• Parasitic- In parasitic symbiosis, one organisms gains something, like
nutrients, at the expense of the other. For example, in the taiga, the grape
vine becomes host for and is killed by the aphid, otherwise known as the
grapevine aphid.
• Commensalism- In commensalism, one organism gains nutrients without
harming the other. An example of this in the taiga is when fungi breaks
down a decaying tree. The decomposer is gaining nutrients, but the tree is
already dead, so no harm is being done.
Food Web/Energy Flow
• At the bottom of the food pyramid/web are the
primary producers, such as grass, moss, and the white
spruce tree. These producers are then consumed by
primary consumers, such as hares, red squirrels, or
moose, or they are broken down by decomposers
(fungi). If it is broken down by a fungi, the energy from
the plant will be passed on to a primary consumer that
eats the fungi, like the red squirrel. The primary
consumers will then be consumed by either secondary
or tertiary consumers. Secondary consumers include
great horned owls, red foxes, and weasels, and tertiary
consumers include wolves, lynxes, and grizzly bears.
Food Web
Human Impact
• Recently, efforts have been made by humans to save
forests, including the taiga. Logging in forests has led to
deforestation, which leads to the displacement,
endangerment, and possible extinction of species who
are native to the area. Hunting is also a major problem
in the taiga. The Siberian tiger, due to logging and
poaching, is a critically endangered species. Species are
beginning to dwindle and disappear. The perhaps most
dangerous effect of human activity in the taiga is acid
rain. The excessive burning of fossil fuels pollutes the
soil and water and harms both plants and animals
native to the area.
Siberian Tiger
Natural Selection
• In the taiga biome, nature favors those who can withstand the cold. Only
the trees with waxy needle-like leaves are able to retain enough water to
survive. Spruce trees, evergreen trees, fir trees, and pine trees are all
favored in this environment because of their needles. Mammals with thick
fur are more likely to survive in the taiga. Moose, wolves, foxes, lynx, and
rabbits all have thick fur to keep warm. This is the reason why lizards are
rarely found in the taiga: they are cold blooded and unable to stay warm.
Other traits that are advantageous to taiga organisms are long legs and
sharp talons. Large mammals, such as moose and caribou, have long legs
for traversing through deep snow. Birds, such as owls, have long, sharp
talons specially designed for hunting prey in snowy conditions. Then,
within each species, there are advantages that lead to more reproduction.
One instance of intrasexual selection occurs in moose. The larger the
antlers are, the larger the males are that the moose can take on in
competition for females and reproduction. Although the large antlers slow
the moose down, they lead to more reproduction.