Vegetation, fire and climate history of the Lesser Caucasus: a new Holocene record from Zarishat fen (Armenia)

Vegetation, fire and climate history are investigated in the 10 000-year record of Zarishat fen located today in the steppe grasslands of Armenia (Near East). Pollen-based climate quantification provides a reconstruction of seasonal parameters. The development of in-situ water-dependant plants and of forests at lower altitude at 8200 cal a BP echoes the shift from an arid and cold [annual precipitation (P-ann)=452mm; mean temperature of the coldest month (MTCO)=-11.1 degrees C)] Early Holocene to a more humid and warmer (P-ann=721mm; MTCO=-6.8 degrees C) Mid-Late Holocene. This marks the onset of lower seasonality, in particular more effective precipitation brought during late spring by the Westerlies. Paralleling the Mediterranean precipitation pattern, precipitation in the Near East and Central Asia decreased during the Mid-Late Holocene in favour of higher seasonality controlled in winter/spring by the Siberian High. Fire history and sedge-based fen development record drier phases at approximately 6400, 5300-4900, 3000, 2200-1500 and 400 cal a BP, which resemble the precipitation pattern of the South-Western Mediterranean and contrast with the Holocene pattern in the South-Central and South-Eastern Mediterranean regions. Arid phases in Armenia are believed to be related to multi-centennial-scale variation of Westerly activity (North Atlantic Oscillation-like).