Resumen

TALAMO, Andrés; TOLABA, Julio; TRUCCO, Carlos  y  ACUNA, Eduardo. Vegetation units and floristic composition in areas of the northwestern Altiplano, Argentina. I. Steppe environments. Ecología en Bolivia [online]. 2010, vol.45, n.1, pp. 4-19. ISSN 1605-2528.

In order to identify and describe vegetation units, we investigated floristic composition and vegetation structure in four physiographicall and scapes of the north western Altiplano of Argentina. We recorded total vegetation cover, density and cover by species, slopes, altitude and exposure in plots randomly placed in sites differentiated by physonomic features of the vegetation, which broadly speaking consisted of shrubby steppes with only one dominant species, shrubby steppes with two dominant species, and grassy steppes. A total 35 taxa of vascular plants belonging to 25 genera and 14 families was recorded. The families with the highest specific richness were Asteraceae (12 species, 34%), Poaceae (five species, 14%), Fabaceae, and Solanaceae (four species, 10.8% each). Over the study region as a whole we designated fourteen vegetation units in total. We compare the phytogeographic characteristics of the areas studied with those of vegetation units studied by other authors, and conclude that sampling effort in these landscapes must be increased in order to enhance natural history knowledge of the Altiplano. Finally, we address aspects of the conservation status of the study region.

Palabras llave : Altiplano; Floristic composition; Plant richness; Puna; Vegetation units.