Hot Deserts Flashcards
Describe the climate in hot deserts
Very little rainfall - less than 250mm a year.
Rainfall patterns vary - might rain once every few years.
Temperatures are extreme due to lack of clouds cover - can reach 45 degrees C in the day, then drop below 0 degrees C at night.
Describe the soil in hot deserts.
Lack of leaf fall limits the soil’s fertility.
Little rainfall means the soil dries out often.
Soil is often shallow with a gravelly texture.
Describe the plants in hot deserts.
Low rainfall means plant growth is sparse but the plants that do grow (e.g. thornbushes & cacti) don’t need much water.
Plants are usually short (e.g. low shrubs or short woody trees) but cacti can grow fairly tall.
Many plants have short life cycles - growing quickly after rain.
Describe the animals in hot deserts.
HDs contain animals adapted to the harsh environment.
Mammals tend to be small and nocturnal (e.g kangaroo rats).
Most birds leave the desert during the harshest conditions but some (like roadrunners) can live there all year round.
Describe the people in hot deserts.
Many people living in deserts grow a few crops near natural water sources - usually in the desert fringes.
Indigenous people are often nomadic - keep travelling to find food and water for their livestock.
What are some plant adaptations in hot deserts?
-Roots either really long to reach deep water supplies or spread out very wide near the surface to absorb most water possible when it rains.
-Many are succulents (e.g. cacti) - large, fleshy stems for storing water and thick waxy skin to reduce transpiration (water loss).
-Some have small leaves or spines to lower surface area & reduce transpiration. These spines can contain toxins to protect the plants from predators.
-Some only germinate after rain (e.g. brittlebrush) - if it’s too dry the seeds stay dormant (inactive). But they grow quickly to make the most of wet conditions.
What are some animal adaptations in hot deserts?
-Nocturnal animals stay cool by sleeping when it’s hottest.
-Many have long limbs or ears - larger surface area to lose heat from.
-Lots live in underground burrows where temperatures are cooler (e.g. desert tortoises).
-Some bigger animals store fat to break down to water when needed (e.g. camels - humps).
-Some get water from food (e.g. cactus mice get it from cactus fruits) and most desert animals minimise water loss through sweat & urine (e.g. kangaroo rats don’t sweat & have very concentrated urine).
-Adapted to cope with sand (e.g. camels’ triple eyelids, long eyelashes, & ability to close their nostrils to keep out sand and also large, flat feet to not sink into sand).
What are development opportunities in the Sahara?
Mineral resources
Oil and gas
Solar energy
Tourism
Farming
Explain mineral resources in the Sahara Desert
Morocco is the world’s 3rd largest exporter of phosphate - used in fertilisers.
Also reserves of iron, copper, lead, and silver.
Explain oil and gas in the Sahara Desert.
Algeria - a leader in oil extraction in the Sahara - around 94% of exports coming from oil and gas industries.
Explain tourism in the Sahara Desert.
It’s small-scale but many people visit the outskirts (e.g. Marrakesh, Morocco) - sandboarding & cross-desert camel treks.
Explain solar energy in the Sahara Desert.
Over 12 hours of bright sunlight everyday is ideal for generating solar power.
A 100 square kilometres solar energy development will be launched in Tunisia between 2018 and 2025 - will supply enough electricity for more than 2.5 million homes.
Explain farming in the Sahara desert.
Water is essential for growing crops (e.g. cotton, corn, and rice) - commercial agriculture only possible with enough irrigation water (e.g. Aswan Dam provides water to Egypt all year round.
