Often deserts are described as arid, barren wastelands as they are the last remaining areas of total wilderness. Yet they are also biologically rich habitats. The vast array of animals and plants are adapted to extremely harsh conditions.
Deserts cover 1/5 of the Earths land, with at least one on every continent. To classify an area as a desert, the rainfall must be less then 10 inches (25 cm) per year. Deserts also come under the classification of drylands. This is where there is a moisture deficit, meaning the area loses more moisture from evapotranspiration than it receives from annual precipitation.
The largest hot desert is the Sahara in Africa, covering 9,400,000 km squared. The temperature can reach highs of 50 Degrees Celsius (122 Degrees Fahrenheit). Hot deserts tend to be found near the Tropic of Cancer and Capricorn.
Deserts can also be cold. Antarctica and Gobi in China and Mongolia are two examples. The temperature can range between -2 to 4 Degrees Celsius in the winter while in the summer it ranges from 21-26 Degrees Celsius. The mean annual precipitation is roughly 15-26 cm in the form of snow.
In all deserts, the amount of precipitation can vary dramatically. One year there could be 5 inches of rain, the next there may be none.
Animal adaptations are very unique to deserts. The Fennec fox lives in the Sahara and has a few useful adaptation so it can survive in the desert;
- Large ears with blood vessels close to the surface to enable faster loss of body heat
- Light coloured coat to reflect heat
- Burrows during the day to avoid heat
- Can receive more moisture from it's prey
Many animals in the desert are nocturnal to avoid the heat of the sun during the day.
Reptiles have hard skin to reduce moisture loss. Side Winder snakes move in such a way that they avoid contact with the hot ground as much as possible.
Plants such as the Prickly Pear, which is a type of cactus, also have special adaptations;
- Stores water in fleshy stems
- Waxy skins seal in moisture and prevents water loss by transpiration
- Leaves are modified as needles for both protection and to reduce water loss
The Creosote Bush has long, lateral tap roots which enable the plant to absorb soil water at a distance in extreme drought and extract soil moisture that is held tightly in the soil. It also has a high surface area to volume ratio by having small leaves to optimise the rate at which heat escapes and moisture is retained.
Plants and animals in the desert are so well adapted to their environment means that they are very sensitive to any change to the environment, such as a new predator.
Deserts cover 1/5 of the Earths land, with at least one on every continent. To classify an area as a desert, the rainfall must be less then 10 inches (25 cm) per year. Deserts also come under the classification of drylands. This is where there is a moisture deficit, meaning the area loses more moisture from evapotranspiration than it receives from annual precipitation.
The largest hot desert is the Sahara in Africa, covering 9,400,000 km squared. The temperature can reach highs of 50 Degrees Celsius (122 Degrees Fahrenheit). Hot deserts tend to be found near the Tropic of Cancer and Capricorn.
The Sahara Desert
Deserts can also be cold. Antarctica and Gobi in China and Mongolia are two examples. The temperature can range between -2 to 4 Degrees Celsius in the winter while in the summer it ranges from 21-26 Degrees Celsius. The mean annual precipitation is roughly 15-26 cm in the form of snow.
In all deserts, the amount of precipitation can vary dramatically. One year there could be 5 inches of rain, the next there may be none.
Animal adaptations are very unique to deserts. The Fennec fox lives in the Sahara and has a few useful adaptation so it can survive in the desert;
- Large ears with blood vessels close to the surface to enable faster loss of body heat
- Light coloured coat to reflect heat
- Burrows during the day to avoid heat
- Can receive more moisture from it's prey
Fennec Fox
Many animals in the desert are nocturnal to avoid the heat of the sun during the day.
Reptiles have hard skin to reduce moisture loss. Side Winder snakes move in such a way that they avoid contact with the hot ground as much as possible.
Plants such as the Prickly Pear, which is a type of cactus, also have special adaptations;
- Stores water in fleshy stems
- Waxy skins seal in moisture and prevents water loss by transpiration
- Leaves are modified as needles for both protection and to reduce water loss
The Prickly Pear originated in the Americas but is now widespread in
Africa, Australia, Asia and Europe.
The Creosote Bush has long, lateral tap roots which enable the plant to absorb soil water at a distance in extreme drought and extract soil moisture that is held tightly in the soil. It also has a high surface area to volume ratio by having small leaves to optimise the rate at which heat escapes and moisture is retained.
Plants and animals in the desert are so well adapted to their environment means that they are very sensitive to any change to the environment, such as a new predator.
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