HOLOCENE TEMPERATURE AND PRECIPITATION HISTORY OF TAYMYR PENINSULA, NORTHERN CENTRAL SIBERIA – A COMPARISON OF TWO POLLEN-BASED TRANSFER-FUNCTIONS

Two statistical approaches have been applied to detailed pollen records from Lama and Levinson-Lessing Lakes, Taymyr Peninsula to achieve a reliable quantitative reconstruction of the Holocene climate. Statistic-information method (Klimanov, 1976; 1984) has successfully used for pollen-based climate reconstructions at many sites in northern Eurasia. This approach is based on relationships between abundances of arboreal pollen in surface samples and modern climate in respective sites. Second approach (Peyron et al. 1998) uses a biomization concept (Prentice et al., 1996), also compares pollen from surface samples with modern climate. It bases on plant functional types (PFT), which are broad classes of plants grouped according to morphology, phenology and climatic requirements, calculated by a summation of percentages of pollen taxa attributed to a given PFT. For use in Russia, Tarasov et al. (1999) established the transfer function between the PFT scores in a set of 1245 surface pollen spectra and modern climate. A comparison of the Holocene climate variations obtained by two methods from the Lama Lake record shows similar patterns of changes in the temperatures of the coldest and warmest months and in annual precipitation, but distinct differences in the amplitudes. Both approaches indicate precipitation was lower than present in the early and late Holocene and higher or similar than present during the mid-Holocene. The thermal optimum occurred after 9000 yr BP. According to the PFT-method, this period is characterized by intensive winter warming, whilst the statistic-information method indicates more significant summer warming. The Holocene climate at the Levinson-Lessing Lake has received different trends. The statistic-information method indicates winter temperatures, summer temperatures and precipitation higher than present throughout almost the whole Holocene. The PFT method, in contrast, suggests these variables had values similar to present during the past 6000 yr BP, following a period of intensive warming during the first half of the Holocene that was associated with a precipitation slightly lower than today.