The espinal is a broad arc of arid land in the interior of Argentina to the north and west of Buenos Aires, extending from the northern Uruguay border west through Santa Fe to Cordoba and south to the Atlantic coast south of Bahía Blanca.

[1] The Köppen climate classification is "Cfa": warm temperate, fully humid, hot summer.

The introduction of cattle in the 17th century had a huge impact, and the original habitat is now found only in isolated patches.

The "caldén" subregion in the south of the espinal has xerophytic forests with many Prosopis caldenia (calden) trees, an endemic species.

The Mar Chiquita lake and the Dulce River swamps are designated a Ramsar wetland that is a key site for endangered neotropical birds.

The wetland supports a rich and diverse fauna with 138 known species of birds, including large breeding groups of Chilean flamingo (Phoenicopterus chilensis).

[6] Endangered birds include yellow cardinal (Gubernatrix cristata), Chaco eagle (Buteogallus coronatus) and Eskimo curlew (Numenius borealis).

[1] Much of the ecoregion has been used for agriculture, and the trees of the sparse dry forests have been used for firewood, fence posts, flooring and furniture.