Palynological data on major Holocene climatic events in NW Iberia.

Three NW Iberia Cantabrian Mountain pollen records are presented. They reflect the main Holocene climatic shifts in the North Atlantic region as recorded in the isotopic data from Greenland ice, Irish speleothems and reconstructed sea surface temperatures. Two brief forest regression episodes reconstructed from pollen may be synchronous with GH-11.2 and GH-8.2 events. At mid-altitude, two woodland expansion phases (7000–6000 14 C yr BP and 4000–2500 14 C yr BP) are separated by a phase of heaths and peat deposits. Major woodland declines occurred during the Galician–Roman Period (which includes the Bronze Age, the Iron Age and the Roman occupation) and from the end of the Medieval Period. The pollen data, backed up by archaeological and historical sources, suggest climatic impact of the Iron Age Cold Period, but are indecisive concerning the Little Ice Age. However, the pollen records do not support any significant ‘Neoglacial’ period (4000–3000 14 C yr BP) influence on NW Iberia. [ABSTRACT FROM AUTHOR]