Reconstruction of vegetation Chitino-Ingoda depression (Transbaikalia) in the Late Holocene

On the basis of detailed palynological studies and radiocarbon Dating of peat deposits Chitino-Ingoda depression of Transbaikalia, the reconstruction of vegetation in the late Holocene. The dated palynological record of peat deposits of the Ingoda river valley for the last 1300-1500 years is received. The vegetation of medium-taiga low-mountain landscapes close in composition to the modern one, represented by light coniferous taiga of pine and larch mixed with birch, was reconstructed. In all pollen spectra dominated by the pollen of Scotch pine. The amount of larch, spruce and fir pollen is insignificant, which is typical for the subrecent spectra of the study area. A permanent presence in the palynological macerate the stomata of needles of Scots pine confirmed throughout the time of the formation of permanent deposits of a pine forest in the higher areas, but in the vicinity of the cut. During the formation of the peat layer in the floodplain of Ingoda, as in its current state, were developed cereal-sedge groups. The presence of Buttercup pollen, ephedra and wormwood in the palino-logical spectra characterizes the vegetation of floodplain areas occupied by meadow and meadow-steppe associations. In the upper part of the section there is an increased content of cypress pollen - a pioneer species in the vegetation of modern post-fire successions. Its abundance coincides with the maximum content of coal microparticles in the palynological spectra, which also characterize the upper part of the section, which together with visual observations of the column of peat deposits indicates the presence of fire phenomena occurring during the formation of the upper five-centimeter layer. The palynological record shows that during the accumulation of the peat layer there were no significant changes in the composition of the regional vegetation of the depression. The middle and lower parts of the section accumulated in more humid climatic conditions, as indicated by the abundance in the deposits of pollen grains of moisture-loving plant taxa-willow and sedge with the constant presence of diatoms. The obtained data are in good agreement with the results of interregional correlations on the basis of palynological data, indicate that in the southern latitudes of the Baikal region in the period from 7000 to 5500 years ago coniferous vegetation has been replaced by a light from the second half of the middle Holocene, no significant changes in the composition of forest vegetation and climate in the future.

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