Hot Deserts- Specification Notes

The living world: Hot deserts:

Hot desert ecosystems have a range of distinctive characteristics.

The physical characteristics of a hot desert:

• <250mm of rain each year.
• High levels of evapouration from extreme heat.
• Located 30^oN and 30^oS of the equator in belts.
• High air pressure, so few clouds. Means temperature can drop below freezing at night.
• Soils have little organic matter, and are usually sandy or stony.

How plants and animals adapt to the physical conditions:

• Plants may have taproots to reach deep water supplies/groundwater.
• Many plants are succulents so store water in their roots, leaves, stems and fruit (e.g. cacti).
• Plants may have thick, waxy skin to reduce water loss, or have thin leaves/spines.
• Camels have fat reserves in their humps, have long eyelashes to keep out sand/dust and have slit-like nostrils to protect from sand.
• Lots of animals are nocturnal and live underground in burrows- this protects them from the high daytime temperatures.

Issues related to biodiversity:

• There is low biodiversity in hot deserts due to the harsh climate and conditions.
• The highest levels are found near water sources, however this is where there is the highest density of the human population as well.

Development of hot desert environments creates opportunities and challenges.

Development opportunities in hot desert environments: mineral extraction, energy, farming, tourism:

• Case study: The Thar Desert.
• Mineral extraction: Most important minerals are gypsum, feldspar, phosphorite and kaolin. Sanu limestone mined in Jaisalmer is used in India's steel industry. Marble is quarried for the construction industry near Jodhpur.
• Energy: Coal used for a thermal energy plant in Giral, large oilfield in Barmer, India's largest wind farm in Jaisalmer and solar power used for water treatment in Bhaleri.
• Farming: Most people are involved in subsistence farming, though…