The Pampas
The Pampas (from Quechua, meaning “plain”) are the fertile South American lowlands that include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, and Córdoba, most of Uruguay, and the southernmost end of Brazil, covering more than 750,000 km² (290,000 square miles). These vast plains are only interrupted by the low Ventania mountain range near Bahía Blanca (Argentina), with 1,300 m height. The climate is mild, with precipitation of 600 to 1,200 mm, more or less evenly distributed through the year, making the soils appropriate for agriculture.
Frequent fires ensure that only small plants such as grasses flourish and trees are exceptional. The dominant vegetation types are grassy prairie and grass steppe in which numerous species of the grass genus Stipa are particularly conspicuous. ‘Pampas Grass’ (Cortaderia selloana) is an iconic species of the Pampas. Vegetation typically includes perennial grasses and herbs. Different strata of grasses occur due to gradients of water availability. The Pampas are home to a wide variety of native species, although there is an almost absolute lack of native trees, except along main watercourses.
Its climate, as in the mid-latitudes, is naturally changeable. Winters are cool to mild and summers are very warm and humid. Rainfall is fairly uniform throughout the year but is a little heavier during the summer. Annual rainfall is heaviest near the coast and decreases gradually further inland. Rain during the late spring and summer usually arrives in the form of brief heavy showers and thunderstorms. More general rainfall occurs the remainder of the year as cold fronts and storm systems move through. Although cold spells during the winter often send nighttime temperatures below freezing, snow is quite rare. In most winters, a few light snowfalls occur over inland areas. Snow is extremely rare near the coast.
Central Argentina boasts a successful agricultural business, with crops grown on the Pampas south and west of the Buenos Aires. In particular, the harvested area of soybeans is on pace to set a record, according to the Food and Agricultural Service. Much of the area is also used for grazing cattle. These farming regions (i.e., modified of disturbed Pampas) are particularly susceptible to flooding during heavy rainfall. In October 2001 an estimated 3.5 million hectares (35,000 km²) of the pampas were flooded, with thousands of hectares of fields and grazing lands being submerged. Buenos Aires reported nearly 250 mm (9.84 in) of rainfall during that month, which is more than double the normal amount.