EcoZone: Deserts
Deserts are found all around the world and there's a great deal to learn about them. Here are a few facts to get you started:
The driest desert on earth is probably the Lut in eastern Iran where it is said not even bacteria can survive. A close contender is the Atacama in Chile.
The hottest recorded desert locality in the world is El Azizia in Libya (580C), closely followed by Death Valley in California (570C).
Many cacti, like the barrel cactus, are ribbed so they can swell and store as much water as possible on the rare occasions when it does rain.
Some deserts are growing – fast. The Sahara has increased by 65 million hectares in the last half century.
Desert sands only move when driven by strong, steady winds – a wind of about 40 km per hour is needed to pick up the sand grains.
The Thar Desert in western India is the most densely populated (by man) hot desert in the world.
Desert plants are superbly adapted to hot, dry conditions but if they are introduced from one continent to another they can become seriously invasive pests. An example is the African Sahara mustard (Brassica tournefortii) which has colonised the Sonoran desert in the USA to the detriment of the native flora there.
The African ass (Equus africanus), which lives in rocky places in the deserts of Somalia, Ethiopia and the Sudan, is the smallest member of the horse family.
The primate (Homo sapiens excluded) that inhabits the most arid environment is the Chacma baboon (Papio ursinus) which lives in the Namib desert. They can obtain moisture from eating desert fruits such as figs.
Some desert animals only breed after it rains, when there will be food enough to raise young. An example is the Desert kangaroo rat (Dipodomys deserti) which has a long tail and hind legs, and hops like a kangaroo. It lives in the deserts of Mexico and the USA.