Lateglacial climate development in NW Romania — Comparative results from three quantitative pollen-based methods

Abstract

This paper provides quantitative reconstructions of the Lateglacial changes in four climate parameters from two fine-resolution pollen profiles in the Gutaiului Mountains, NW Romania. Climate estimates are based on two modern analogue techniques (with and without considering vegetation types) and weighted averaging partial least squares regression (WA-PLS), giving evidence for several climatic fluctuations during the period from > 14,700 to 11,500 cal. yr BP. The comparative results of the two modern analogue techniques show consistent trends of climate changes that are also coherent at both sites, but these results appear to largely disagree compared with climate reconstruction provided by WA-PLS. The modern analogue techniques revealed four intervals with low temperatures: prior to 14,700 cal. yr BP, between 13,950 and 13,800; 13,400 and 13,200; and 12,700 and 11,700 cal. yr BP. The temperature declines were more pronounced for winter than for summer, suggesting an intensification of seasonality, which together with a drop in precipitation indicates an increase in continentality. The Younger Dryas is the most pronounced cooling phase with winter temperatures ~ 14–16 °C colder than modern conditions, annual and summer temperatures ~ 2–5 °C and ~ 2 °C, respectively below present ones. Precipitation was ~ 400–500 mm, half that of present. During the Bølling and Allerød, summer temperatures were close to modern values (13 to 17 °C), whereas winter (− 6 to − 12 °C) and annual temperatures (0.5 to 6 °C) as well as precipitation were (550 to 700 mm) lower, indicating more continental conditions compared to the present-day climate.