Radiocarbon-dated paleobotanical and palynological samples record comp
lex changes of vegetation and climate in northeastern Russia during th
e Late Pleistocene and Holocene. Since the Kargin Interval (middle Wis
consin equivalent), which started 50 ka ago, we can distinguish two pe
riods that were colder than the present. The Kirgilyakh was the earlie
st Karginsk cool period, dating to 45-39 ka BP. The second significant
cool period dates to 33-30 ka BP. The boundary between the Kargin Int
erval and the last Late Pleistocene glaciation (Sartan, late Wisconsin
equivalent) dates from 27 ka BP. The sharp change from herbaceous mos
sy tundra (Sartan) to light-coniferous larch forests (Holocene) in nor
theastern Russia dates to 12.5 ka ago. The Holocene thermal maximum, l
inked to the expansion of woody plants into the modern barren-ground t
undra, dates from 9.5-8 ka BP.