[4] The Lagunas de Guanacache, Desaguadero y del Bebedero in Mendoza Province form the most important wetland in the ecoregion, designated a Ramsar site.

[4] There are areas of cactus scrub, xerophilous open woodland, and vegetation adapted to rocky, sandy and salty conditions.

Other plants found in different conditions include Baccharis salicifolia, Tessaria dodonaefolia, Suaeda divaricata and Allenrolfea vaginata.

[2] Several endemic species have evolved in isolation since the Oligocene such as Ramorinoa girolae and Gomphrena colosacana, found in the Sierra de las Quijadas National Park, and Halophytum ameghinoi, a succulent herbaceous plant in the Halophytaceae family.

Common mammals include screaming hairy armadillo (Chaetophractus vellerosus), pink fairy armadillo (Chlamyphorus truncatus), cougar (Puma concolor), South American gray fox (Lycalopex griseus), Patagonian weasel (Lyncodon patagonicus), guanaco (Lama guanicoe), and southern mountain cavy (Microcavia australis).

Vulnerable or endangered mammals include plains viscacha rat (Tympanoctomys barrerae), pink fairy armadillo (Chlamyphorus truncatus), strong tuco-tuco (Ctenomys validus), viscacha rat (Octomys mimax), Roig's pericote (Andalgalomys roigi), delicate salt flat mouse (Salinomys delicatus) and Patagonian mara (Dolichotis patagonum).

Threatened birds are peregrine falcon (Falco peregrinus) and Chaco eagle (Buteogallus coronatus).

[2] Endangered birds include yellow cardinal (Gubernatrix cristata) and Eskimo curlew (Numenius borealis).

[2] Reptiles include Argentine red tegu (Tupinambis rufescens), false tomodon snake (Pseudotomodon trigonatus), Patagonian lancehead (Bothrops ammodytoides), boa constrictor (Boa constrictor), ringed hognose snake (Lystrophis semicinctus) and Chaco tortoise (Chelonoidis chilensis).

The habitat in the settled areas has been greatly changed, with trees cleared for use as fuel and lumber and to make way for agriculture and mineral exploitation.

580,000 square kilometres (220,000 sq mi) of the ecoregion has been affected by erosion caused by deforestation and excessive grazing by sheep, goats and cattle.

[2] The Guanacache, Desaguadero y Bebedero system has been affected by various natural and man-made changes that have caused the area of lagoons and marshes to shrink significantly.