Hot Deserts Flashcards
What is a desert?
An area of land that receives no more than 25 cm of precipitation a year.
Where are deserts found?
Hot deserts are found near the tropics of Cancer and Capricorn.
What is the climate like?
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.
Hot deserts have two distinct seasons: summer, when the temperature ranges between 35-40°C, and winter, when the temperature ranges between 20-30°C.
What is the soil like?
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.
What are xerophytes?
Plants with adaptations which allow them to live in hot and dry conditions
How have cacti adapted to the desert?
Spines
Waxy skin
Water storage
Widespread roots
How do small leaves help desert plants?
These ensure that less water is lost from the plant by transpiration because the leaf has a smaller surface area.
How so spines help desert plants?
Some plants have spines instead of leaves, eg cactuses. Spines lose less water than leaves so are very efficient in a hot climate. Spines also prevent animals from eating the plant.
How does waxy skin help desert plants?
Some leaves have a thick, waxy skin on their surface. This reduces water loss by transpiration.
How does water storage help desert plants?
Some plants, known as succulents, store water in their stems, leaves, roots or even fruits. Plants which store water in their leaves and stems also have a thick waxy skin so that they lose less water by transpiration.
How have camels adapted to the desert?
Long eyelashes
Slit nostrils
Wide, flat feet
Fur
Sandy coloured fur
Hump to store fat
What is desertification?
The process of land turning into desert as the quality of the soil declines over time.
What are the causes of desertification?
Over grazing
Increasing population
Deforestation (wood removal)
Climate change
How can desertification be managed?
Bunds
Appropriate technology
Afforestation
How does afforestation reduce desertification?
The roots of trees hold the soil together and help to reduce soil erosion from wind and rain.
