In all things of nature there is
Something of the marvelous.
The Earth is covered by hundreds
Of types of ecosystems.
For convenience, ecologists
Group these into a few Biomes.
Biomes are areas that have
Distinctive climates and
Organisms.
Tropical rain forests occur in
A belt around the earth near
The equator.
They are always humid and
Warm and get about 250 cm
Of rain a year.
They get strong sunlight all year,
Maintaining a climate with little
Seasonal variation.
In tropical rainforests, plants
Grow in layers.
These layers are
Emergent
Canopy
Understory
The canopy is near the top
Where 95% of the sunlight
Is absorbed.
Tropical rainforests
Used to cover 20% of the Earth,
But today they cover only
7% !!
When buying products, look
For the “rain-Forest Friendly”
Label.
Temperate rain forests
Occur in North and South
America, and Australia.
Tree branches are draped with
Mosses and tree trunks are
clothed in lichens.
In Temperate deciduous forests,
Trees drop their broad, flat
Leaves each fall.
The temperature changes and is
Between 100° and below freezing.
They are moist, receiving between
75-250 cm of precipitation each
Year.
The Taiga (boreal Forest) is
Rough and sparsely vegetated.
The taiga is the northern
Coniferous forest just below the
Artic circle, with extremely
Cold and long winters.
The growing season is only
50 days and most precip is snow.
The west African plains, called
Savannas, contain the greatest
Collection of grazing animals
On earth – along with the
Magnificent predators that
Hunt them.
Savannas have periods of
Heavy rainfall followed by
Periods of drought.
Temperate grasslands are
Found in the interiors of
Continents where there is
Too little rainfall for
Trees to grow.
In addition to the American
Prairies, there are the steppes
Of Russia, and the pampas
Of south America.
Americ
a
Kazakhstan
The Chaparral is a biome that
Occurs in the mid-latitudes, about
30 degrees north and south
Of the equator.
Hot, dry summers; and mild, wet
Winters.
Deserts are defined as areas
That receive less than
25 cm of precip each year.
Deserts often occur in the rain
Shadow of mountains.
The tundra is a biome without
Tall trees that lies north of
The artic circle.
The frozen tundra soil supports
Mostly tall rough grasses.
It contains mostly permafrost,
Permanently frozen soil.
The wetlands are areas of land
That are covered with water
For at least part of the year.
There are freshwater wetlands,
Marine ecosystems, and
Estuaries.
Freshwater wetlands are
Marshes and swamps.
Both have tons of plants
And animals.
They trap CO2 and other
Pollutants, control floods, and
Produce commercial products.
An estuary is an ecosystem
Where fresh water from a
River mixes with salt water
From the ocean.
Estuaries are among the most
Productive ecosystems because
They contain plenty of light
And nutrients.
Coral reefs are limestone islands
In the sea that are built by
Coral animals called polyps.
Thousands of species of plants
And animals live in the cracks
And crevices, making them
The most diverse ecosystems
On earth.
The ocean covers nearly
75% of the Earth’s surface.
The surface can have plants,
While there are all kinds
Of strange creatures
Down deep.