New insights into postglacial vegetation dynamics and environmental conditions of Península Avellaneda, southwest Patagonia, revealed by plant macrofossils and pollen analysis

Abstract

Reconstruction of the history of past events becomes more objective when considering an increased number of possible indicators. Combining plant macrofossil analysis with pollen analysis has the potential to give a more detailed picture of the composition of the local vegetation. Patagonia has been the focus of several palaeoclimatic studies, in particular of latitudinal variations in southern westerly winds, which have global implications. However, palaeoecological reconstructions using plant macrofossils in conjunction with pollen analysis are still scarce. We analysed the plant macrofossils contained in two peat sequences from Península Avellaneda (located in the Lago Argentino basin, southwest Patagonia) and integrate these results with pollen information. Plant macrofossils and pollen records provide a well-resolved history of vegetation and catchment conditions starting from ca. 13,000 cal yrs BP. We also investigated the development of plant communities following the retreat of glaciers, with emphasis on the expansion of Nothofagus species (which were restricted under glacial climates) and particular reference to Nothofagus pumilio. These results provide an example of how plant macrofossil analysis (taxonomic, taphonomic and statistical) in combination with pollen analysis results in a better understanding of postglacial environmental history.