Download Taiga Animals

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
Transcript
TAIGA
The Boreal Forest
Taiga Facts





“Taiga” comes from the Russian word for forest
The taiga is the largest biome in the world
The forests within the Mat-Su valley are
classified as taiga
The names ‘boreal forest’ or ‘northern forest’
are sometimes used in place of ‘taiga’
Did you know that ‘boreal’ comes from the
name of the Greek goddess of the North Wind?
Introduction to the Taiga


The Taiga exists a nearly continuous belt of coniferous trees
across North America, Europe and Asia
Since it is growing in areas that were formerly glaciated, and
there is patches of permafrost, there is a variety of successional
stages that can be found.

This is called a ‘forest mosaic’
Climate



Long, severe winters (up to six months with
mean temperatures below freezing) and short
summers (50 to 100 frost-free days)
Mean annual precipitation is 15 to 20 inches, but
low evaporation rates make this a humid climate
Conditions are similar to the tundra, just a little
less extreme
Geography

There are many water bodies found within the
boreal forest:


Bogs, fens, marshes, shallow lakes, rivers and
wetlands
Forests cover approximately 19.2 million square
miles - (33%) of the world's land surface area,
and boreal forests cover about 6.4 million square
miles, or 1/3 of all the forests
More geography

There are latitudinal zones within the boreal
forest.
tundra/taiga ecotone
 an open coniferous forest (the section most properly
called taiga)
 and a mixed needleleaf evergreen-broadleaf
deciduous forest, the ecotone with the Temperate
Broadleaf Deciduous Forest

Taiga Soils


Soils in this forest are called podzols, from the
Russian word for ash (the color of these soils)
Podzolization occurs as a result of the acid soil
solution produced under needleleaf trees.
This means that iron and aluminum are leached
from the surface, and deposited in lower layers
 Clays and other minerals migrate to lower layers,
leaving the upper one sandy in texture

Taiga Trees

By far the most dominant tree species are
conifers


well-adapted to the harsh climate, and thin, acidic
soils
Four main genera found in the taiga
spruce (Picea)
 fir (Abies)
 pine (Pinus)
 and the deciduous larch or tamarack (Larix).

Taiga Trees

Broadleaf deciduous trees and shrubs are found
in early successional stages
Most common are alder (Alnus),
birch (Betula), and aspen (Populus)
and willow (Salix).

There are also many varieties of berries and low lying
plants that are very important to the balance of the
ecosystem.
But why so many evergreens?

Conical shape


Needleleaf



narrowness reduces surface area through which water may be
lost (transpired),
the needles of boreal conifers also have thick waxy coatings
which protected from drying winds.
Evergreen habit


promotes shedding of snow and prevents loss of branches.
retention of foliage allows plants to photosynthesize as soon
as temperatures permit in spring, rather than having to waste
time and energy growing leaves
Dark color

the dark green of spruce and fir needles helps the foliage
absorb maximum heat from the sun and begin
photosynthesis as early as possible
Taiga Animals

The North American
boreal forest offers
breeding grounds to over
200 bird species, as well
as being home to species
such as Lynx, Black Bear,
Moose, Coyote and
Timber Wolf
Taiga Animals



Since most of the trees have
cones, there are animals that
have evolved adaptations to
obtain seeds from the cones
Conversely, the trees have
adaptations to deter this,
usually spines on the cones.
Crossbills (which have
crossed beaks) are highly
efficient seed extractors.
Taiga Animals



Moose are common large
herbivores in the boreal forest.
Caribou use the forest for shelter
in the worst parts of the winter.
Moose (Alces alces) generally prefer deciduous browse and
herbaceous plants, while caribou (Rangifer terrendus)
scavenge for lichens and can eat conifer needles.

Thus, the two large herbivores have different food requirements
- moose being an early successional (young forest) species, and
caribou a late successional (older forest) species.
Taiga Animals

The beaver (Castor canadensis), on which the early
North American fur trade was based, is also a
creature of early successional communities,
indeed its dams along streams create such
habitats.
Taiga Animals


Bear (Ursus) are
abundant in the boreal
forest, along with wolves
(Canis lupus).
Snowshoe hares (Lepus
americanus) and lynx (Felis
lynx), which have
unusually large feet to
walk across snow, are
also common.
Taiga Animals

Various members of the
weasel family (e.g.,
wolverine, fisher, pine
martin, mink, ermine,
and sable) are extremely
characteristic of the
boreal forest.
Taiga Animals



Among birds, insect-eaters like the wood
warblers are migratory and leave after
the breeding season.
Seed-eaters (finches, grosbeaks, sparrows
and chickadees) and omnivores (e.g.,
ravens) tend to be year-round residents.
During poor cone years, these yearround residents may leave the taiga in
winter and can be seen at residential bird
feeders.
To sum it all up…





The taiga is sometimes called the boreal forest.
Conditions are similar to the tundra (as far as
temperatures, sunlight, etc) but not quite as
extreme
The dominant vegetation is needle-leafed trees.
There is a variety of wildlife—much greater
biodiversity than the tundra
We live in the taiga!