Desert

The Atacama Desert is the oldest and most arid non-polar desert on Earth. In Chile it forms a continuous belt of almost 1200 kilometres from the Chilean border with Peru south to the Río Elqui in the Coquimbo Region, where a semiarid environment predominates. Contained between the Pacific Ocean and the Andean cordillera, with peaks exceeding 6000 m, this formidable landscape presents extraordinary contrasting extremes. These extremes include a hyper-arid desert almost devoid of vegetation due to an annual rainfall of less than 1 mm, and a coastal flowering desert where episodic rainfall gives rise to a spectacular flowering event on certain years. The latter and the coastal fog oasis formations are major centres for plant endemism. At about 3300 m, a high plateau known as Puna, is characterised by vast salt lakes and grasslands with cushion and mat-forming plant species. Here the average annual rainfall is over 100 mm. Unlike other deserts, which typically experience extremely hot temperatures, the Atacama Desert is relatively cool with an average temperature of 18°C in the coast and less than 10ºC in the high Andes. Survival strategies of desert plants broadly fall into two categories, those that are either drought-evaders or drought-tolerant. The former includes annuals and geophytes, which complete their life cycles in the most favourable season (when water is available), and drought-deciduous shrubs; the latter includes cacti and fleshy-leaved perennials, which have water storage tissues, and evergreen shrubs or trees with extensive root systems and physiological adaptations.

Endemic Taxa in Desert