La vegetación puneña en la provincia de Mendoza, Argentina
Roig, Fidel A.; Martinez Carretero, Eduardo
This work aims at studying the vegetation of the southern extreme of the Puna in Sierra de Uspallata, Mendoza. In this area Puna plant communities occur between 2700-3000 m asl and the Cardonal (Pre-Puna) and Monte vegetal communities below 2700 m asl. The whole area is affected by cryoturbation processes in winter. Soils are superficial, neutral, poor in nitrogen and calcium, with medium phosphorus content, and rich in potassium. The entire Puna is affected by intense night frosts during the summer period. The climate is cold and dry. Rainfall occurs in summer on the eastern slope of the Sierra de Uspallata and comes from the Atlantic Ocean; while on the western slope there is winter rainfall coming from the Pacific Ocean. Plant communities are classified by correspondence analysis, being associated with both water availability and soil texture. Three new classes are described, two of them provisory: Stipo-Lycietea fusci class. nov. containing the Puna plant communities on the west slopes, and Baccharidetea grisebachii class. nov. prov. include associations of riparian communities depending on occasional streamflows and Dolichlasietea lagascae class. nov. prov. that include communities on rocky outcrops. For associations, alliances and orders see the syntaxonomical synopsis on page 604.