Sub-Boreal

Kremenetsky (1991) who gathered his pollen data in southern Ukraine and Moldova, argues that in the early Sub-Boreal (4200-2700 BP) the climate in that area became cool and dry; pollen spectra showed the disappearance of Ulmaceae from the forests in the Moldavian highlands; warm-loving trees such as oak and lime withdrew from the forests of Volhynia.