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This paper presents the results of palynological, macrofossil and peat analyses that were conducted on deposits from a profile collected from the Wielkie Błoto mire near Bałupiany (north eastern Poland). The investigation revealed that the recorded changes of vegetation span the period from the decline of the Younger Dryas (ca 9600 cal. yr BC) to the late Subboreal or early Subatlantic chronozone, but due to a 40 cm long sediment gap a complete reconstruction was not possible. At the beginning, the area was occupied by steppe and tundra communities together with abundant Juniperus stands. A subsequent expansion of birch (Betula) woodlands with pine (Pinus sylvestris) took place in the Preboreal chronozone in which a rise in the water level and/or basin deepening was recorded at the site as well. The domination of such woodlands lasted to the end of the Boreal chronozone when Corylus avellana expanded rapidly. In the Atlantic chronozone multispecies deciduous forests developed with Tilia cordata and Quercus, while Ulmus together with Alnus spread in damp habitats. During this chronozone, traces of the occurrence of Carpinus betulus were detected in the macrofossil analysis, while the pollen analysis failed to record its presence. The expansion of Carpinus betulus and Picea abies was characteristic of the Subboreal chronozone when both taxa presented antagonistic optima. Alone in north-eastern Poland, there was a re-expansion of deciduous forest in the younger part of the Subboreal chronozone caused probably by low human impact, which is reflected in the whole profile. The first probable traces of human activity were noticed in the Atlantic chronozone and attributed to peoples of the Mesolithic or Early Neolithic cultures, while the first evidence of cultivation was correlated to the Bronze Age. However, the low resolution of the radiocarbon dates did not allow a more precise reconstruction of the chronology. The analysis of macrofossils and tissues indicated two episodes of oligotrophication of the mire. The first one took place during the Boreal chronozone, while the second fall in trophy was triggered by spruce expansion in the Subboreal chronozone. On the other hand, a rise in human impact during the first Carpinus betulus maximum caused eutrophication of the mire. |
