Pollen Paleoclimatology in the Mediterranean since Messinian Time

Abstract

A schematic reconstruction of climatic changes in the Mediterranean may be carried out on the basis of pollen. Research on the Messinian series remains incomplete, although some vegetation belts have been identified as related, first, to a subtropical dry climate and then to a cool period, perhaps related in some manner with a glacial front. Upper Pliocene glacial events are known, and indicated by palynological evidence. A point of controversy is the Plio-Pleistocene boundary, usually identified by the migration of "cold" markers in the Mediterranean. According to the most recent hypothesis, their migration was caused not by a synchronous but rather by a previous cooling climate phase. The disappearance of taxa such as Sciadopitys and Taxodillm is of note. The Quaternary glacial and interglacial epochs record different palynological features in the Mediterranean area: Cold front assemblages in the north may correspond to "pluvial" ones in the south (e.g., Greece, Israel, North Africa) with exceptions related to the presence of mountains and distance from the coast. Consequently, an alternation of glacial steppes and cool forests with temperate forests occurs in the north, while to the south glacial-related wood assemblages may occur in succession with xerophytic (dry condition) vegetation. Particular consideration can be given to the last interglacial (R/W), which presents a mild-wet climatic "Pontic" phase; this latter is subdivided into two parts. It is possible to denote palynological changes in relatively recent time related to small climatic variations; oscillations like those of the Dryas and others, however, appear less well marked in the Mediterranean area. Pollen diagrams record the appearance of cultivated plants during the postglacial optimum. The present chapter is intended as a synthesis only, with particular attention paid to the Italian region.