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The Roman and Medieval Warm Periods in Georgia
Reference
Kvavadze, E.V. and Connor, S.E.  2005.  Zelkova carpinifolia (Pallas) K. Koch in Holocene sediments of Georgia - an indicator of climatic optima.  Review of Palaeobotany and Palynology 133: 69-89.

What was done
In a review and analysis of the pertinent scientific literature, the authors "present some observations on the ecology, pollen productivity and Holocene history of Zelkova carpinifolia [a Tertiary-relict tree whose pollen "is almost always accompanied by elevated proportions of thermophilous taxa"] to further understanding of Quaternary climatic trends."

What was learned
"Zelkova carpinifolia," in the words of Kvavadze and Connor, "is a mesophilous tree, requiring warm conditions."  As a result, and "because Zelkova species require heat and moisture during the growing period," they say that "the discovery of fossil remains in Holocene sediments can be a good indicator of optimal climatic conditions."

In this regard, they note that "Western Georgian pollen spectra of the Subatlantic period show that the period began [about 2580 cal yr BP] in a cold phase, but, by 2200 cal yr BP, climatic amelioration commenced," and "the maximum phase of warming [was] observed in spectra from 1900 cal yr BP."  This interval of warmth was Georgia's contribution to the Roman Warm Period.

A cooler phase of climate, during the Dark Ages Cold Period, "occurred in Western Georgia about 1500-1400 cal yr BP," according to the two scientists, but it too was followed by another warm period "from 1350 to 800 years ago," which, of course, was the Medieval Warm Period.  During portions of this time interval, they report that tree lines "migrated upwards and the distribution of Zelkova broadened."  What is more, they present a history of Holocene oscillations of the upper tree-line in Abkhasia - derived by Kvavadze et al. (1992) - that depicts slightly greater-than-1950 elevations during a portion of the Medieval Warm Period and much greater extensions above the 1950 tree-line during parts of the Roman Warm Period.

Finally, following the Medieval Warm Period, Kvavadze and Connor note that "subsequent phases of climatic deterioration (including the Little Ice Age) ... saw an almost complete disappearance of Zelkova from Georgian forests."

What it means
Both the Roman and Medieval Warm Periods have been identified in various parts of European Georgia via studies of Zelkova carpinifolia pollen found in local sediments; and portions of these warm climatic intervals were likely even warmer than what it was there during ~ AD 1950, which is the "present" of Kvavadze and Connor's study.

Reference
Kvavadze, E.V., Bukreeva, G.F., Rukhadze, L.P.  1992.  Komp'iuternaia Tekhnologia Rekonstruktsii Paleogeograficheskikh Rekonstruksii V Gorakh (na primere golotsena Abkhazii).  Metsniereba, Tbilisi.

Reviewed 11 May 2005