Transcript The Desert Biome

The Desert Biome
Desert Characterization
A Desert is a region
on Earth which
receives less than 10
in of annual rain fall,
and is generally taken
over by high
temperatures.
Deserts cover one
fifth of all of Earth’s
surfaces
Usually found around
30N
Temperature
Between 20 and 40
degrees Celsius.
Many deserts receive
little rainfall.
Due to this low rainfall
we have high
temperature shifts
between daytime and
nighttime
temperatures.
Average Temperatures
40
35
30
25
20
15
10
5
0
Hot Desert
Semiarid Desert
Costal Desert
Average
Day Temp.
(Celcius)
Average
Night
Temp.
(Celcius)
Formation of a Desert
Many deserts have been formed by the
flow of air masses over the planet.
As the earth turns on it’s axis, it makes
huge air swirls causing the hot air to rise
over the equator and flow north and
southward.
This in turn sucks up moisture while
warming the land which causes it to
become dry.
Desert Soil
Caliche is a reddishbrown to white layer of
soil found in many desert
soils.
This type of soil is formed
by plants releasing water
and carbon dioxide.
Soils that form in arid
climates mineral soils and
have low organic
contents.
Water Channels
In the desert, underground
channels carry water from
mountains that are most of the
time near by into the desert.
If the channels were not
covered by the soil it the water
would evaporate.
Moisture in the desert can
come from sources such as
rain, sweat, dew, pools, lakes,
sap, and breath, these
evaporate quickly in the hot air.
Flora
Saguaro
Cactus
Fish Hook Cactus
Barrel Cactus
Brittle Bush
Joshua Tree
Mojave Aster
Triangle-leaf Bursage
Flora Adaptations
Only second to the Rainforest, the Desert has
the most variety of plant species. Adaptations:








Store water in their stems or leaves;
Some have no leaves or small seasonal leaves that only grow
after it rains.
Long root systems spread out wide or go deep into the ground to
absorb water;
Short life cycle, germinating in response to rain, growing,
flowering, and dying within one year. These plants can evade
drought.
Spines to discourage animals from eating plants for water;
Waxy coating on stems and leaves help reduce water loss.
Flowers that open at night lure pollinators who are more likely to
be active during the cooler night.
Slower growing requires less energy.
Fauna
Addax
Cactus Wren
Desert Night Lizard
Blind western snake
Thorny Devil
Vulture
Armadillo
Jack Rabbit
Javelina
Fauna Adaptations
Animals in the desert must survive in a hostile
environment. Intense heat, searing sun, and lack
of water are just a few of the challenges facing
desert animals.
Animals that live in the desert have many
adaptations. Including





Leg speed, sharp claws and/or teeth (tusks), spikes or quills, or
armor for protection
Cold blooded – to avoid having to heat or cool themselves
Some animals have specialized kidneys to conserve water used
for urine
Some organisms don’t sweat – to avoid water loss
Long ears on a jack rabbit, so that excess heat can escape
Video
Montage

Eyewitness: Desert