Pe. Tarasov et al., Last Glacial Maximum climate of the former Soviet Union and Mongolia reconstructed from pollen and plant macrofossil data, CLIM DYNAM, 15(3), 1999, pp. 227-240
An improved concept of the best analogues method was used to reconstruct th
e Last Glacial Maximum (LGM) climate from a set of botanical records from t
he former Soviet Union and Mongolia. Terrestrial pollen and macrofossil tax
a were grouped into broad classes - plant functional types (PFTs), defined
by the ecological and climatic parameters used in the BIOME1 model. PFT sco
res were then calibrated in terms of modern climate using 1245 surface poll
en spectra from Eurasia and North America. In contrast to individual taxa,
which exhibit great variability and may not be present in the palaeoassembl
ages, even in suitable climates, PFTs are more characteristic of the vegeta
tion types. The modified method thus allows climate reconstruction at time
intervals with partial direct analogues of modern vegetation (e.g. the LGM)
. At 18 kBP, mean temperatures were 20-29 degrees C colder than today in wi
nter and 5-11 degrees C colder in summer in European Russia and Ukraine. Si
tes from western Georgia show negative, but moderate temperature anomalies
compared to today: 8-11 degrees C in January and 5-7 degrees C in July. LGM
winters were 7-15 degrees C colder and summers were 1-7 degrees C colder i
n Siberia and Mongolia. Annual precipitation sums were 50-750 mm lower than
today across northern Eurasia, suggesting a weakening of the Atlantic and
Pacific influences. Reconstructed drought index shows much drier LGM condit
ions in northern and mid-latitude Russia, but similar to or slightly wetter
than today around the Black Sea and in Mongolia, suggesting compensation o
f precipitation losses by lower-than-present evaporation.