Deserts 2 What are deserts like What types

Deserts 2 What are deserts like? What types of plants live in deserts? What types of animals live in deserts? Why do people live in deserts?

Wind blown particles of sand dust have a scouring action on the rocks. The geographic term for wind-blown is “Aeolian”. The scouring action is know as “Abrasion”, • • 1. Hot Deserts are places where rain rarely falls. They get less than 250 mm of rain each year. What caused this rock formation to be this shape, do you think?

• • 2. Most people have a false image of deserts from films that they have seen. Some deserts are sandy and incredibly hot, but there are cold deserts too. What caused this landform to be like this? Wind-blown particles of sand piling up on each other on the windward side of the dune. That side is convex. Gravity will cause the dune to avalanche from time to time so the leeward side of the dune is steeper and concave.

• • 3. Some deserts reach the sea and so get more moisture than 250 mm of rain. The plants grow better than areas of desert that are further in land. What reasons can you think of why the plants have not covered all of the sandy area shown in this photograph?

• 4. Many deserts are just vast areas of bare rock. What are the two reasons for the shapes of the rocks in this photograph?

• 5. Even in the hot deserts the temperature may fall below freezing at night. What reasons can you think of for there being both rocks and sand in this photograph?

• • 6. Many deserts are huge, flat stony plains with sparse coverings of plants such as cacti. Cactus plants store water in their stems and have extremely long roots that reach deep into the ground. Why are there more plants in this photograph than in the (a) sandy and (b) rocky deserts?

• • 7. What all deserts have in common is that all plants find it difficult to grow there. Many plants grow for only a few days after a rain storm and their seeds lie dormant for up to hundreds of years, awaiting the chance to grow if water comes their way. What reason can you think of for the plants in this photograph to grow tall and thin?

• • 8. Cactus leaves are very small and some have even become spikes to reduce water loss. The saguaro cactus that grows in Arizona contains a powerful poison to animals and birds. What has caused the plants in this photograph to burst into flower?

• 9. Even though deserts are difficult places for plants to survive in there a lot of different species of plants living in them. Why are there lots of different species, even in a desert?

• • Some animals have become adapted to living in deserts. Many spend much of their lives searching for water. Many only come out at night, sipping the dew that forms on rocks and plants. Kangaroo rats, gerbils and meerkats get much of their moisture from gnawing seeds and plant roots. 10. Why have these rodents adapted in the following ways; 1. 2. 3. 4. jumping as a method of movement? Large eyes? Large ears? A long tail? 11. Why do most desert spiders catch their prey by jumping rather than by spinning a web?

• • • The camel has been called “the ship of the desert” because of all the adaptions that they have to suit them for desert life. A camel may go for many days without water. But when it gets the chance it can drink 120 litres in about 10 minutes. It does not store water in its humps, it stores fat which expands as the camel drinks more water. Thirsty camels have floppy humps! 12. Which camel is a dromedary, which is a bactrian? 13. List as many other adaptions that camels have that you can think of.

• • • Some isolated settlements are scattered throughout the world’s deserts. Some villages are small and found at oases, where water supplies are available. Some settlements are close to oil wells and where they are near the coast they have often developed into port cities. The majority of people that live in, or on the edge of deserts, have been nomads. Nomads move from place to place with herds of animals searching for grazing and water. 14. Why are these homes in Mexico built in caves under these cliffs? 15. Why do people not live in this town any more?

Deserts 2 What are deserts like? What types of plants live in deserts? What types of animals live in deserts? Why do people live in deserts?