Saxicolous and riparian vegetation of a piedmont in central-western Argentina

Four plant communities were determined through floristical and non-metric analysis: a Dolichlasium lagascae community in crevices on sunny rock outcrops; a Cercidium praecox ssp. glaucum community on sunny slopes; an Artemisia mendozana–Adesmia trijuga community on shady slopes; and a Eupatorium buniifolium community on dry riverbanks. The discriminant function analysis showed that the first group corresponds to the sunny rock outcrops discriminated by Na content (r=0•53, p<0•05), the second group is for sunny slopes discriminated by electric conductivity and the third for shady slopes–riparian discriminated by the (Ca+Mg) content (r=0•54, p<0•05). A pattern of primary succession on outcrop surfaces is proposed