During the ice age, environmental changes caused by glaciations and warmings, followed by further cooling, led to regular cycles of change in vegetation in a given geographical area, with the animal world naturally following it. In Central Europe, in the belt of today’s deciduous forests (including the Carpathian Basin), during the glaciations, the cold and dry climate was home mainly to dwarf shrubs and grassy vegetation. At the beginning of the warming period, fast-growing pine and birch trees formed alluvial forests. Later, during the middle of the interglacial period, thanks to the warming, more humid climate, deciduous forests covered the area. With the beginning of cooling, during the initial accumulation of ice cover, coniferous (pine) forests pushed the deciduous forests southward. Then everything started over again, with dwarf shrubs and grasses replacing the trees.
However, each stage differed from the others, as the composition of the vegetation changed from cycle to cycle. As time went by and got closer to present day, the forests have become increasingly similar to those of today. In our days, in the middle of the Flandrian interglacial period, we are in the midst of a period of ice melting. According to theory, in 5-6,000 years, another cooling period and ice accumulation is likely to begin. However, human impact is also involved now in this process.