Modern pollen/climate calibration for southern South America

Using the response surface technique a modern pollen/climate calibration is presented for the mid-latitudes in southern South America between latitudes 39°S and 44°S, extending from the west coast in Chile across the Andes into the Patagonian steppe region. The climate parameters identified that relate to the present-day pollen distribution of the nine most important pollen types (Nothofagus dombeyi-type, Nothofagus obliqua-type, Podocarpus, Weinmannia, Caldcluvia/Eucryphia-type, Cupressaceae, Myrtaceae, Misodendrum and steppe-types) are summer precipitation, summer and winter temperatures. Using the modern pollen/climate data set, three fossil pollen records (Mallı́n Aguado and Lago Moreno, east of the Andes, and Caunahue, west of the Andes) are interpreted in terms of these three seasonal climate parameters. Despite intervals of no-analog fossil pollen assemblages, the reconstruction shows similar climate trends on both sides of the Andes during the last 21 000 cal. yr BP (17 000 yr BP), with summer precipitation as low or markedly lower than today prior to 17 000 cal. yr BP (14 500 yr BP), as high or higher than today between 15 000 and 12 500 cal. yr BP (12 500 and 10 500 yr BP), and again lower than today between 12 500 and 8000 cal. yr BP (10 500 and 7200 yr BP). Summer and winter temperatures were low (or high) when summer precipitation was high (or low).