A reference database of the pollen representation of the current vegetation in the Dry Puna of Argentina: Contributions to the interpretation of pollen fossil sequences and archeological evidence during the Holocene

Abstract

The present research is framed within an interdisciplinary archeological project that aims to reconstruct the environmental conditions in which human occupations developed in the locality of Barrancas, Dry Puna Argentina, during the Holocene. The aims of this work were to: (1) study the regional vegetation and the modern pollen dispersal-sedimentation process; and (2) generate a reference database for interpretation of the fossil pollen records of the Holocene in the Dry Puna (3) provide information for the study of the relationship between human populations and vegetation in the area during the Late-Holocene. The results show that the main pollen types that characterize the regional vegetation were represented in the surface samples (herbaceous steppe, shrub steppe, mixed steppe, and vegas). Also the environments with evidence of anthropic impact were identified by specific plant species and the corresponding pollen grain. The representation of the vegetation was quantified according to the different pollen types. The study used indices of association to establish relationships between modern pollen and vegetation, and showed a weak association for Solanaceae and Verbenaceae; an over-representation of Ephedrae, Alnus acuminata, Malvaceae, Chenopodiaceae-Amaranthaceae; an association of Asteraceae; the absence of association of Cactaceae and Portulacaceae; and a strong association of Poaceae. These results allow us to specify the interpretation of fossil records and past environments in relation to anthropic modifications on the landscape.