ИСТИНА

The spatial-temporal vegetation and climate dynamics through the Eemian (Mikulino) Interglacial have been examined along the latitudinal transect (50-60° N). The territory under consideration extends from the Central Europe (10° E) to the East European plain (up to the Ural Mountains, 55° E). Pollen data from more than 40 sections have been analysed in order to reconstruct vegetation and climate conditions at three time-slices during the Interglacial. The time slices were selected to represent the most characteristic stages: the Pinus-Quercetum mixtum-Corylus phase (zones E3 and E4a after Menke and Tynni, 1984; or zone M4 after Grichuk, 1982); the Carpinus-Picea phase (zone E5 or zone M4 respectively); and the Pinus –Picea- Abies phase (E6 after Menke and Tynni, 1984) or Picea phase (zone M7 after Grichuk, 1982). Climatic characteristics (mean temperatures of the warmest and coldest months) for each time slice were determined using the floristic method of paleoclimatic reconstruction – the method of climagrams, developed in the Laboratory of Evolutionary Geography IG RAS (Grichuk, 1985). The result of this investigation is a series of maps showing vegetation pattern and temperature distribution during the Eemian. As follows from considered data, changes of environment and climate became more contrast from west to east. At the same time, the main phases in the evolution of vegetation appear to be similar throughout the latitudinal belt under consideration. The interglacial optimum (Carpinus-Picea phase) was marked by an essential similarity of vegetation all over the region investigated. Nevertheless, a floristic provincial differentiation is detectable. Mixed broad-leaved forests in Central Europe included species that indicate a certain oceanicity of climate (Ilex aquifolium, Hedera helix, Taxus baccata, etc). The participation of these plants decreases eastward. Of those species, only Tilia platyphyllos and Viscum album are found in the Eemian pollen assemblages in the eastern part of the transect. On the other hand, plant communities of the cooler intervals differed noticeably from west to east, primarily in the proportion of broad-leaved species in vegetation. When considering the reconstructed parameters of the Eemian climate, it is essential that winter temperatures show greater positive deviation from the present day values than summer ones. As for winter temperatures, their positive deviations were more considerable in the east of the transect than in the west– 10°C and 2°C respectively. Summer (July) temperature deviations were no more than 1°C both in the east and in the west. At the Eemian (Mikulino) Interglacial optimum, the latitudinal gradient of temperatures was considerably reduced. Continentality of climate in the east of the continent was much less than at present as a result of evident penetration of oceanic influences farther eastwards.