desert ecosystems
DESCRIPTION
DESERT Ecosystems. Deserts cover more than one fifth of the Earth's land, and they are found on every continent. A place that receives less than 10 inches (25 centimeters) of rain per year is considered a desert. - PowerPoint PPT PresentationTRANSCRIPT
DESERT ECOSYSTEMS
DESCRIPTION Deserts cover more than one fifth of
the Earth's land, and they are found on every continent. A place that receives less than 10 inches (25 centimeters) of rain per year is considered a desert.
Despite the common conceptions of deserts as dry and hot, there are cold deserts as well.
PLANTS Desert plants may have to go
without fresh water for years at a time. Some plants have adapted to the dry climate by growing long roots that tap water from deep underground. Other plants, such as cacti, have special means of storing and conserving water. Many desert plants can live to be hundreds of years old.
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Some desert plants are covered with tiny hairs that reflect the sun and prevent evaporation. They look grey from a distance.
Some desert plants such as rabbit brush have tiny leaves to prevent evaporation.
Big sagebrush has three types of roots. Shallow roots absorb rapid rainfall. Longer roots that soak up any water in the soil. And a large taproot that can extend 6 feet or more to soak up deep ground water.
Big sagebrush has two types of leaves. Large leaves grow in the spring to help the plant grow quickly and absorb water. These leaves fall off during the rest of the year so the plant can conserve water.
Many types of cactus are able to store water in their spongey tissue to save for later. Cactus leaves are spines to protect them from predators who might also like that water supply!
COMMON ANIMAL ADAPTATIONS Avoiding activity during the
daytime when temperatures are highest.
Finding a cool place to hide such as a burrow, the shade of plants, or creating a den.
Shedding extra fur or feathers during the summer.
Having large ears to cool blood vessels.
DESERT FOOD WEBS EXAMPLE
Herbivores include:
Mammals such as mice, rats, rabbits, sheep, deer, squirrels, prairie dogs
Birds such as quail and doves
Insects such as butterflies, moths, ants, and aphids
Reptiles such as tortoises and iguanas
Carnivores include:
Mammals such as coyotes, fox, bob cats,
Birds such as owls and hawks
Arachnids such as spiders and scorpions
Reptiles such as snakes and lizards
DECOMPOSERS INCLUDE fungi, bacteria,
termites, earth worms, and dung beetles