Monte Desert Monte Desert The Monte Desert is a South American ecoregion, lying entirely within Argentina and covering approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza Provinces, plus the western half of La Pampa Province and the extreme north of Río Negro Province. The desert lies southeast of the Atacama Desert in Chile, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba. The delineations between the Monte Desert, the Atacama Desert, and the Patagonian Desert are not exact and the desert seems to be more-or-less continuous with the
Patagonian Ice Sheet than the extremely steep ones of present-day Patagonia. Unlike the Laurentide Ice Sheet or the ice sheets of Northern Europe, the Patagonian Ice Sheet did not cause major extinctions or loss of biodiversity. This is because the flora remaining to the north of the ice were isolated by the Atacama Desert and were able to speciate easily wherever suitable microclimates occurred. In fact, most of the original Antarctic flora survives today on land occupied by the ice sheet. However, there are indications that during the last deglaciation (17,500 years ago), the rapid melting of the northernmost extension of the Patagonian