Las comunidades vegetales del piedemonte de la precordillera de Mendoza

Resumen

A geobotanic study of the Mendoza Precordilleran foothill has lead to determine that there are two deñnite vegetation levels in the piedmont: one of them mostly with Larrea cuneifolia which covers an extention of 750 m to 1.100 m, over 1.100 m to 1.500-1.800 above the sea level.
Through the sociological analysis of each vegetation level and the corresponding comparison it had been established that the Larrea cuneifolia level has a “suculent climate” while the Larrea divaricata one shows a “trong tendency to a hemicriptophytic climate”.
The differences between both levels, and the behaviour of Larrea divaricata as lower level, allow to State that the species of Larrea dominant at each level have different niches. Finally, as a sociological conclusión, four new associations are described:
I - Riparian association of temporary rivers: Proustio—Psiletum retamoidei.
II - Bed river association of temporary rivers: Argemone— Petunietum axillaris.
III — Litosolic Triasic and Terciary shaded slopes association: Adesmietum trijgae.
IV - Litosolic Triasic and Terciary sunny slopes association: Astericietum glauci.
Tlie characteristic, diferential, adjoining and occasional species have been determined for each case.