Forest ecosystems of late pleistocene of Yakutia

Abstract

The appearance of the late Pleistocene landscapes of the Northern Hemisphere is still a debated issue. The existing reconstructions of the Late Pleistocene plant cover of Yakutia, which are based on the treelessness of vast territories, rather contradictoryly explain the variegated composition of the faunistic complex, where forest species of animals occupied quite noticeable positions, as well as paleobotanical finds of larches, made to the north of their modern range. Most likely, Dahurian larch in the Late Pleistocene was more widespread than it is now, which is explained by its adaptation to the long-term permafrost and frequent fires. Based on the late Pleistocene finds of pollen and macroscopic remains of larch and tree-like birch trees in the north of Yakutia, we assume a rather wide participation of forest communities in the composition of the vegetation cover. A steady analysis of the fauna allows to draw a conclusion about the savanna appearance of Late Pleistocene landscapes. At the same time, pasture grazing of large and giant representatives of the mammoth fauna made it possible to support the wide distribution of meadow phytocenoses, often a post-pyrogenic search. Post-pyrogenic succession processes in the Late Pleistocene and at present are quite similar, with one exception. Now there is no zoogenic stabilization in the process of reforestation at the stage of development of grassy formations, which in the late Pleistocene led to the widest development of meadow phytocenoses. In the Holocene, the vegetation of Yakutia acquired a modern taiga shape, with which enrichment of the fauna with strictly forest species (squirrels, chipmunks, flying squirrels) is connected. The deep transformation of the vegetation cover of Yakutia occurred at the border of the Holocene and Pleistocene, which led to the gradual extinction of representatives of the mammoth fauna as the area of pastures decreased.