The reserve has a desert climate with the temperature varying dramatically between day and night. Rain is more frequent in summer, with an average high of 3 millimetres.
This area is made up of two salt flats: Salar de Tara, located 120 kilometres east of San Pedro de Atacama and 440 kilometres northeast of Antofagasta, and Salar de Aguas Calientes, reaching an altitude of up to 4,860 meters above sea level. In 1996, Salar de Tara was designated a Wetland of International Importance by the Ramsar Convention. It features both permanent and seasonal lakes. The largest of these is Tara Lake, which is fed by the Zapaleri River. Salar de Tara was formerly filled by an overflowing lake that covered of area and has left prominent shorelines, 24 of which are recognizable on the eastern side, as well as river deltas. ;Flora and fauna The flora is characterized by the presence of high altitude wetland, as well as yellow straw, broom sedge, tola de agua and tola amaia, and coirón, which can be observed on flat and hilly terrain and on the slopes of volcanoes and hills Salar de Tara provides a habitat for various rare and endangered species of wildlife. Some, like the southern viscacha, vicuña and Darwin's rhea, are classified as endangered species. Others, such as Andean goose, horned coot, Andean gull, puna tinamou and the three flamingo species inhabiting in Chile are considered vulnerable. The conservation status of the tawny tuco-tuco and the Andean fox is unknown. The latter lives in all the sections of the reserve. Wind erosion features occur in this area.
Salar de Pujsa
Salar de Pujsa is a salt flat located southwest of Salar de Tara, 83 kilometers from San Pedro de Atacama, and northeast of Acamarachi volcano. With a maximum altitude of 4,585 metres above sea level, Pujsa is considered the most isolated section in the reserve. The salt flat receives the waters of the Quepiaco and Alitar creeks and was listed as a Ramsar site in 2009. Birds that migrate across the hemispheres use the salt flat and surrounding land as a staging area, including the Wilson's phalarope. The flora found here is similar to that found in the Tara and Aguas Calientes areas, characterized by high altitude wetland, yellow straw, broom sedge, tola de agua and tola amaia, and coirón, which can be observed on flat and hilly terrain. The fauna includes vizcachas, chululos, Andean foxes, cuyos, Andean flamingos, Chilean flamingos, ñandúes, Andean condors and eagles, among others.
This area is formed by two sub-sections, Soncor and Quelana. Both comprise lagoons lying over the Salar de Atacama, the largest salt flat in Chile at an altitude of 2,305 metres with an extensive salt crust.
Soncor section
The Soncor area includes the Chaxa, Puilar and Barros Negros lagoons. Despite the extreme conditions, the Salar de Atacama sustains a wide variety of species including Chilean and Andean flamingos, the Andean avocet, the yellow-billed teal, the crested duck, the puna plover and Baird's sandpiper. Various plant species ground around the edges of the lagoons, such as Distichlis spicata, Ephedra and cachiyuyo, among others. The Sistema hidrológico de Soncor, like the Salar de Tara, is a Ramsar protected site. It comprises four shallow salt lakes.
Quelana section
Located 10 kilometres from the path to Chaxa lagoon, the Quelana section features extensive salt crust and saline mud. The terrain is flat with an average altitude of 2,300 metres. It shares much of the same flora and fauna of the Soncor section, including the three species of flamingos present in Chile as well as eagles, swallows, burrowing owls and geese.
This section includes archaeological sites such as the village of Tulor as well as the Cordillera de la Sal mountain range, which reaches altitudes of 2,624 metres. The range was formed by the sequential folding of an old salt lake that eventually dried and was forced upwards by the movement of tectonic plates. White-bellied fat-tailed mouse opossums can be found in this area.
Tambillo
This section is to the nearest to San Pedro de Atacama and is characterized by an extended Tamarugo forest of 370 hectares, which is unique in this region. Tambillo contains similar fauna to the other sections of the reserve, including the Andean flamingo, Chilean flamingo, horned coot, silvery grebe, Andean gull, greenish yellow finch, grey fox, Andean fox, chincol, swallows, and falcons.
