Transcript Desert

Deserts have a very
limited variety of plants. The most
common types of plants in the
desert are the succulents.
Succulents are plants that store
water in their enlarged fleshy
leaves, stems, and/or roots.
Succulent plants are adapted to
store water for longer periods of
time.
Some examples of plants that live in the desert are cacti, Joshua trees,
palm trees, sagebrush, and yuccas. Most deserts have little life, and most animal
life that can be found in the desert is only active at night.
This is because there is nothing in the desert to sustain heat during
periods of nighttime.
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Natural Boundaries
They are found on the leeward side of mountains where a rain shadow is
created because as the clouds move up the mountains they lose their moisture.
Once they reach the other side of the mountain they evaporate moisture from the
soil. Other desert areas are made because the prevailing winds are too far from
bodies of water.
Global Distribution
There are two major belts of deserts, one along the tropic of Capricorn,
and the other along the tropic of Cancer. Most deserts are between 30 degrees
north and 30 degrees south of the equator.
The spring season is short; only February
and March, while the summer stretches from April
to the middle of September. Fall ranges from the
middle of September to November, and winter is
from December to January.
In the spring there is the highest average
rainfall and moderate temperatures around 20
degrees. During the summer, the average rainfall
falls to around 0 mm and the temperature rises to
around 30 degrees. The Fall is the same as the
summer, but the temperatures gradually fall to the
twenties. During the winter the temperature falls to
around 15 degrees, and there may be a small
amount of rainfall.
Running Birds
Running birds require very little water to
survive. Animals included in this group are the
ostrich and the roadrunner.
General Mammals
These animals depend on permanent water
holes. Animals included in this group are: antelope,
goats, sheep, and camels.
Desert Rodents
Desert Rodents live mostly
underground during the day, surfacing for food
only at night. They can survive drinking no
water at all, deriving all they need from the
metabolism of their food. Animals included in
this group are: bats, gerbils, rats, and rabbits.
Reptiles
Reptiles also live underground
during the day, and surface at night to feed
with the mammals. Some reptiles such as
the horned toad can control their metabolic
heat production by controlling their heartbeat
and rate of body metabolism. Some animals
in this category are: lizards, horned toads,
and snakes.
Insects
When it rains, dormant insect
eggs and pupae spawn crickets,
grasshoppers, bees, wasps, beetles,
moths, butterflies, and ants, such as this
honeypot ant (left).
Plants
Desert plants have evolved ways of
conserving and efficiently using water available to
them. Flowering plants usually live for only a day
or so; their seeds lie dormant in the sand until it
rains. These are called ephemerals.
Woody desert plants have long root
systems that reach deep water sources.
Photosynthesis is done in the stems instead of
the leaves in some plants.
Desert lands are used for farming.
Such use of desert lands contribute to
the accumulation of salt on surface
soil, eventually rendering it useless.
People mine the water reservoirs deep
beneath the desert. This water is
irreplaceable. Also, burning and
overgrazing the lands bordering the
desert damages the plants, enabling
the deserts to encroach on arable
land. This process is called
desertification.
The United Nations declared that the desert could cover 35% of the earth’s surface
because of desertification. Poor farming could lead to the loss of desert species,
some of which are already endangered.
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