Stable Isotope Composition (C and N) of Vegetation in Subtropical Andes: Piedmont ‘Anomaly’ and its Implications for Paleo (Ecology) and Human Diet Reconstruction

ARANIBAR, JULIETA; MOLINA, JULIETA ARCO; NEME, GUSTAVO; ROIG, FIDEL; CABRAL, DIEGO; QUIROGA, GISELA; DAUVERNÉ, ARMANDO; ÁLVAREZ, LEANDRO; GIL, ADOLFO

Environmental Archaeology

Taylor and Francis Group

Lugar: Abingdon; Año: 2023 p. 1 - 14

1461-4103

Isotope baselines are fundamental to infer diets, and to evaluate trophic relationships betweenhumans, animals, and plants. In this study, we aim to detect spatial patterns of δ13C and δ15N ofdifferent plant types (C3, C4 and CAM) along environmental gradients in the eastern slopes ofthe southern Andes, in order to use them as a baseline to reconstruct animal diet, mobility, andtrophic relations in the area. The stable isotope composition of dominant plants was analyzedalong an environmental gradient from the mountains to the plains in southern Mendoza. Theexpected isotope gradients of increasing δ13C and δ15N with decreasing altitude andincreasing aridity was not found in our region. The spatial distribution of the C3/C4 ratioshowed a non-linear pattern, with higher C4 abundances at intermediate altitudes, probablygiven by atmospheric circulation patterns, which generate aridity and C4 dominance atintermediate altitudes. These climate, geologic, and vegetation patterns may affectecosystem and animal δ13C, which also showed non-linear trends in previously publishedmaterial. These non-linear trends open the opportunity to explain previous δ13C resultsobtained from collagen of human and animal bones, which follow the C3/C4 ratio found inthis study.