Desert by Lauren Tierney and Keren Duff.


deserts.jpg
(Click To See Work Citied)

Introduction

When you hear the word "desert" you think of a hot place with very little plants or animals, and nothing for miles around. All deserts are very dry and receive less then 25 centimeters of rain per year. Some deserts are hot-the hottest place on earth is a desert (the Sahara desert- up to 189 degrees Fahrenheit), and others are cold. Also, some people live in deserts and deserts are filled with plant and animal life. Deserts are very vast and cover about 30 percent of the Earth's surface, making them very important in the world.

Climate


Gold_Sky.jpg
(Click To See Work Citied)
temperature-in-sahara.JPG

Deserts are typically hot and dry places because they are located near the Tropic Of Cancer, the Tropic Of Capricorn, and the equator. However, during the night the temperature can reach below freezing in the months of December to February. However, in the Sahara desert during the summer at night the average temperatures fall between 83 to 73 degrees Fahrenheit. In July the Sahara desert reaches the boiling temperature of 113 to 122 degrees. Furthermore, the sand reaches the temperature of 170 degrees Fahrenheit, and the rocks are the temperature 100-110 degrees Fahrenheit. Surprisingly, the air in the deserts are not still, many winds blow across the deserts, carrying the hot and dry air with them when they leave. These winds are called the harmattan, because they are so dry when they leave the deserts and enter new areas they turn green leaves yellow and harden leather. Overall deserts are a blistering, dry, and windy place that receives hardly any rain all year. ( Biomes of the Earth by Michael Allaby p 51-71.)





Precipitation


desert_rain.jpg
(Click To See Work Citied)


In the deserts there are gullies, rivers that had made an impression in the earth then dried, that are 7 to 10 feet wide. Crossing these gullies will not be a hazard to one's health leading to death however, staying in one or camping in one for an extended amount of time is potentially deadly. The gullies could fill up with water in a mater of seconds with no warning. Where is the water coming from one may ask? In the desert, which means dry arid land, it rarely rains, clouds pass by in the sky but are often too small to produce rain. If they manage to make raindrops, they evaporate in the air before it can reach the ground. A big raindrop falls at the speed of 200 miles per hour, most likely to land on high land like a mountain. The temperature on the mountain is lower then the desert, so when water vapor starts to fall vapor condenses causing cumulonimbus clouds that can bring big thunderstorms and heavy rain. The rain falls on the mountain and the water flows between rocks and gaps that lead to the gullies. The gullies play a major part in the desert's ecosystem, without them animals would be forced to find other ways to survive without water until the next big storm over the desert's land. Everything in the desert arrives without warning, flash floods, caused by storms, damage and kill many people if they flow through the town. When is does rain, the water sinks through the sand until it reaches an impermeable layer of clay, this water is called ground water. The inhabitants in the desert are lucky if they get more then 10mm a month, the total rain fall is only 25cm. (Desert by unknown 45-47)


Living1.gif
The Average Monthly Precipitation ( Click To See Work Citied)

Click here to see a picture of the water cycle.





Animals



The majority of animals in the desert consist of small desert cats such as the Puma, Sand Cat, Pallas Cat, and Lynxes. The Puma cat is found only found in American deserts and eat Jackrabbits.
Puma.jpg
A Puma (Click To See Work Citied)
The Sand cat inhabits any deserts from the Sahara to Central Asia. The cat is called the Sand Cat because it has sand color fur to blend in with its surroundings, the dark rings on the tail is the only thing the sticks out in the sand. The animal also has pads on its paws that are covered with fur to protect the paws from the deadly temperatures of the sand. Like most animals of the desert, the Sand Cat hunts at night when the temperature is less deadly. The Pallas cat lives in the deserts from Iran to Western China and are the same size as a normal house cat, but only stockier. The Pallas has short legs and longer fur, it is also nocturnal and spends days in rock crevices, caves and burrows made by other animals. Lynxes are the biggest of felis cats and they stalk its prey in dry open deserts from Africa to India. They have long legs, to run at a greater speed, long pointed ears with hair on the end. Like the other cats, this one also hunts at night, or at least in cool weather. ( Desert by unknown p 102-103)
desert_chain.gif
A Food Web Of the Desert ( Click To See Work Citied)
hot_desert_.gif
Food Chian Of Desert Animals ( Click For Work Citied)

The Oxogen Cycle

external image oxcycle.jpg

Plants

external image saguaro-cactus.jpg
Plants in the desert need to be able to live for long periods of time without water. One example of this type of plant is a cactus. Cacti are one type of plant that has adapted its physical structure to enable it to survive in the desert. They collect water through an extensive network of very shallow roots that take in a lot of water when there is even the slightest rain. They are then able to hold onto this water really well, storing it in both their stems and their roots. They have no leaves, so they do not lose water through transpiration, and they have waxy skin to prevent water from evaporating. The spines on their skin provide some shade and also channel any available water back into the plant. (DesertUsa)

Sunlight

cartoon_sun_st6.gif
In the desert, because there is so little rain, it is sunny most of the time. The sun is so hot that it evaporates the water too quickly, and does not cool down enough to allow precipitation. The sun makes the desert really hot, up to nearly 200 degrees (F) The animals in the desert often struggle to find enough shade to cool down under. Also, the sun's rays bounce off the sand, creating reflexive heat, and making it even hotter on the ground. The ground holds onto heat even into the night. (Survival)


The Cheetah
449px-Maasai_Mara_Cheetah_2.jpg
A Cheetah (Click For Work Citited)


The cheetah is one of the fastest animals reaching the speed of 70mph and can reach that speed in three seconds, this makes up for their inability to climb. The cheetah is a carnivore that hunts its pray with vision rather then sent, they mostly eat animals under 88 pounds. Their diet consists of gazelles, antelopes, impalas, zebra, wildebeest, guineafowl, and hares.
As one can see from the information above, the cheetah is at the top of the food chain. The only treat to a cheetah is another cheetah or a human. They are the kings of the desert, with their retractable claws similar to those of a cats that allow them extra grip in catching the pray. However, cheetahs do have their vulnerabilities and and are unable to adapt to new environments. ( http://en.wikipedia.org/wiki/Cheetah)


Click HERE to view the work citied.