Types of Forests
Tropical
(Rainforests)
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Canopy is often closed (little light reaches
below)
A canopy opening happens when a tree falls
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Many trees are covered with epiphytes
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Plants competing for the light fill the space
Epiphyte- plants that grow on other plants instead
of in the soil
Rainfall determines the vegetation growth rate
Rainforests of the Earth
Rainforest Mammals
Rainforest Birds
Rainforest Reptiles and others
Coniferous Forests
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Has cone bearing trees (pine, spruce, fir, and
hemlock)
Also called temperate rain forests
Warm, moist air from the pacific ocean supports these
unique communities
They are usually dominated by one or a few species
of trees
The Taiga is the largest terrestrial biome on earth
Receives heavy snowfall but the cone shape of the
trees prevents branches from breaking
Currently, they are being heavily logged.
Taiga
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The Northern
Coniferous Forest
stretches from
North America to
Eurasia.
The southern
border of the artic
tundra is called
the TAIGA.
Taiga Pictures
Temperate Deciduous
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Dense stands of trees
Occur where there is enough moisture to support
growth of large trees
More open than rain forests, but not as tall
Has distinct vertical layers
Mammals in these forests hibernate and some migrate
to warmer climates
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Deciduous- plants that drop their leaves before winter
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This is done because temperatures are too low for photosynthesis
Deciduous Trees and Winter
Dormancy
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Deciduous trees begin to lose their leaves
when temperatures begin to get colder and
the days become shorter
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Circadian Rhythm- a 24 hour cycle that
organisms internally live by
What causes leaves to fall?
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This happens in 3 steps:
1.
2.
Cells die at the base of each leaf because of forming cork
that cuts off the water and nutrients for the leaf
Green chlorophyll turns to other types of chlorophyll that
can use sunlight better
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3.
Xanthophylls: yellow light
Carotenoids: yellow and orange light
Anthocyanins: scarlet and purple light
Leaves fall to the ground
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This prevents trees from being damaged because of freezing
temperatures and strong winds
The tree remains dormant in the winter until longer days and
warmer weather cause new leaves to grow