Deserts

Match

Match the following

hot desert

hot dessert

cold desert

cold dessert

• hot desert

• hot dessert

• cold desert

• cold dessert

​Lesson Objectives

​To be able to locate the hot desert biome.

To describe why hot deserts are an extreme environment.

To explain how plants and animals survive in this ecosystem

Open Ended

What do you think has happened here?

​Hot deserts

Open Ended

How could we define hot deserts

​Hot deserts

​A hot desert is a land of extremes.
Extreme heat and extreme dryness

​Watch the video clip and make notes about the hot desert biome.

Multiple Choice

How many mm of rain does a desert get a year?

• 250mm

• 25mm

• 2500mm

• 2.5mm

​Hot desert location

​Most hot deserts are found near the Tropics of Cancer and Capricorn, between 15-30° north and south of the Equator. The largest hot desert is the Sahara in Africa which spans the whole width of the continent.

Categorize

Options (12)

Great Basin Desert

Peruvian Desert

Atacama Desert

Patagonia Desert

Sahara Desert

Arabian Desert

Turkestan Desert

Great Indian Desert

Gobi Desert

Kalahari Desert

Namib Desert

Great Sandy Desert

On which continent would you find each of these deserts

North/South America

Asia

Australasia

Africa

​Desert Climates

​

The climate is very hot. Summer day time temperatures can exceed 40°C. However, at night the temperature can drop below 0°C.

The climate is very dry with less than 250 mm of rainfall a year. There is also a big variation in temperature between day and night.

​Desert Climates

​

Despite being called hot deserts and having daytime temperatures of up to 50C. Deserts can be very cold at night.

Sometimes the night time temperature in the desert can fall below freezing. This makes it a really difficult place to live.

The difference between day and night temperatures is know as diurnal temperature range.

​Desert Climates

Open Ended

1) What is the peak temperature?

2) How much rain falls in December?

3) Which months have no precipitation?

​Desert Climates

​

1) What is the peak temperature? 35C

2) How much rain falls in December? 2mm

3) Which months have no precipitation? June July, September

Drag and Drop

Hot deserts are ​

Placeholder

areas of land with poor quality, sandy ​

Placeholder

, typically receiving less than 25cm of ​

Placeholder

  annually. Summer daytime  temperatures can reach or exceed 50 degrees ​

Placeholder

, although they get very ​

Placeholder

at night.

Drag these tiles and drop them in the correct blank above

dry

soil

precipitation

Celsius

cold

wet

rock

humidity

Fahrenheit

hot

​The desert ecosystem

​Hot deserts have an extreme climate and challenging environment. There is very little biodiversity in hot deserts because of the harsh climate. Few species are specialised enough to survive there. Plants and animals which do survive there have adapted to difficult conditions. The biotic or living components and the abiotic or non-living components of the hot desert rely on one another.

Match

Match the following

• biotic

• abiotic

• diurnal range

• biome

• ecosystem

living components of an ecosystem

non-living components of an ecosystem

the difference between the highest and lowest temperatures in a day

a large scale ecosystem

a biological community of interacting organisms and their physical environment

• living components of an ecosystem

• non-living components of an ecosystem

• the difference between the highest and lowest temperatures in a day

• a large scale ecosystem

• a biological community of interacting organisms and their physical environment

​Desert Soil

​

• Desert soils are thin, sandy, rocky and generally grey in colour.

• Desert soils are very dry. When it does rain they soak up the water very quickly.

• The surface of the soil may appear crusty. This is due to the lack of rainfall. As it is so hot water is drawn up to the surface of the soil by evaporation. As the water evaporates, salts are left behind on the surface of the soil.

​Desert Plants

.Hot deserts have distinct characteristics that allow certain species to thrive in such an extreme environment. Plants and animals have developed adaptations which allow them to survive in hot and dry conditions

Multiple Choice

Which is the best definition of "adapted"

• To remain unchanged in new conditions
• To ignore new conditions or environment
• To refuse to adapt to new conditions
• To adjust to conditions or environment

Open Ended

How can plants be adapted to hot desert environments?

​Desert Plants

​Plants with adaptations which allow them to live in hot and dry conditions are called xerophytic. This means they have adapted to live in hot and dry environments.

​Watch this video clip and make notes about how these plants are adapted to the hot desert environment

​Desert Plants

​

• Thick, waxy skin to reduce loss of water and to reflect heat

• Large, fleshy stems to store water

• Thorns and thin, spiky spines or glossy leaves to reduce water loss

• Spikes protect cacti from animals wishing to use stored water

• Deep roots to tap groundwater

• Long shallow roots which spread over a wide area

• Plants lie dormant for years until rain falls

Draw

Draw a plant that will be happy in the desert environment. You can use your imagination but must include factors that will help it survive in the desert

​Animals of the desert

​As well as plants, some animals are adapted to life in the desert. They need to overcome a lot of extreme conditions such as hot temperatures, cold nights, lack of water, few plants and lots of sand.

Open Ended

How might animals be adapted for hot deserts?

​Desert Iguana

​

The desert iguana can stand hotter temperatures than other lizards, remaining active in up to 46º C.

It changes colour to regulate body temperature. It is darkest in the morning to absorb more heat from the sun, and turns nearly pure white by early afternoon to reflect sunlight. The desert iguana also has a nasal salt-secreting gland that allows it to void salty body waste while conserving water.

​The camel

​Camel Adaptations

​

• large, flat feet - to spread their weight on the sand

• thick fur on the top of the body for shade, and thin fur elsewhere to allow easy heat loss

• a large surface area to volume ratio - to maximise heat loss

• the ability to go for a long time without water - they lose very little water through urination and perspiration

• the ability to tolerate body temperatures up to 42°C

• slit-like nostrils and two rows of eyelashes - to help keep out sand

​Lesson Objectives

​To be able to locate the hot desert biome.

To describe why hot deserts are an extreme environment.

To explain how plants and animals survive in this ecosystem

​Homework