Biomas!!

The desert biome
Deserts are arid regions, generally receiving less than ten inches of precipitation a year, or regions where the potential evaporation rate is twice as great as the precipitation. Deserts cover around one fifth part of the earth surface. Most deserts have a considerable amount of specialized vegetation, as well as specialized vertebrate and invertebrate animals. Soils often haveabundant nutrients because they need only water to become very productive and have little or no organic matter. Disturbances are common in the form of occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.

Atacama Desert ( Chile )
The Atacama Desert is a virtually rainless area in South America, it occupies 40,600 square miles (105,000 km2, two timesthe size of Costa Rica)in northern Chile, composed mostly of salt basins (salares), sand, and felsic lava flows towards the Andes.

Location: Chile: coordinates 24º30¨s 69º15¨w
Climate:
The Atacama is arguably the driest place on earth and is virtually sterile because it is blocked from moisture on both sides by the Andes Mountains and by the Chilean Coast Range.

Rainfall:
The averagerainfall in the Chilean region of Antofagasta is just 1 millimeter (0.04 in) per year. Some weather stations in the Atacama have never received rain. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971. It is so arid that mountains that reach as high as 6,885 meters (22,589 ft) are completely free of glaciers and, in the southern part from 25°S to 27°S, mayhave been glacier-free throughout the Quaternary though permafrost extends down to an altitude of 4,400 meters (14,400 ft) and is continuous above 5,600 meters (18,400 ft). Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years.

Temperature:
The Atacama is actually a pretty cold place, with average daily temperature ranging between 0°C and25°C. It also has a very low humidity. The Atacama Desert is considered to be one of the driest coastal deserts in the world. Vegetation must contend with an annual rainfall of 0.6 mm in Arica and 2.1 mm in Iquique. The Atacama becomes slightly less arid as it moves southward. The average monthly temperatures in Iquique range from 14.5ºC in September to 21ºC in March.

Human occupation:
TheAtacama Desert again became a source of wealth from the 1950s onwards due to copper mining. The Escondida and Chuquicamata porphyry copper mines are located within the Atacama Desert.
The Pan-American Highway runs through the Atacama in a north-south trajectory.
The Atacama is sparsely populated, with most cities located along the Pacific coast. In interior areas, oases and some valleys have beenpopulated for millennia, being the seat of the most advanced Pre-Columbian societies found in Chile. These oases have had little population growth and urban development, and have, since the 20th century, faced conflicts over water resources that are needed for the coastal cities and the mining industry.
It is a shock then to learn that more than a million people live in the Atacama today. Theycrowd into coastal cities, mining compounds, fishing villages, and oasis towns. International teams of astronomers—perched in observatories on the Atacama's coastal range—probe the cosmos through perfectly clear skies. Determined farmers in the far north grow olives, tomatoes, and cucumbers with drip-irrigation systems, culling scarce water from aquifers. In the altiplano, the descendants of theregion's pre-Columbian natives (mostly Aymara and Atacama Indians) herd llamas and alpacas and grow crops with water from snowmelt streams.
Getting water:
Rainfall is so scarce that remote communities long had to import water by truck, an expensive and inefficient process in order to survive. Finally, however, some coastal residents discovered how to make use of the one form of precipitation they...