The late Quaternary vegetational history of northwest Greece

Abstract

SUMMARYThe mountainous region of northwest Greece has often been cited as a possible area for the existence of temperate tree taxa during the last glacial. This series of papers examines the vegetational history and sedimentary history of two small basins in the Pindus mountain range of northwest Greece. The two basins are 18 km apart but at contrasting heights of 285 and 1800 m. The present paper describes results from the lowland basin of Gramousti lake. Techniques of pollen analysis, plant macrofossil analysis, sediment chemistry, mineral magnetics and radiocarbon dating are employed to reconstruct both the vegetational and sedimentary history of the basin. The sequence extends c. 14000 BP to c. 1000 BP. Palaeobotanical studies suggest that, during the lateglacial, vegetation in this lowland region was dominated by herbaceous taxa indicative of an open environment. Of the trees, only Quercus and Pinus were present, in low numbers. The lateglacial/postglacial transition was represented by an expansion of oak woodland and a reduction in steppe vegetation. Quercus dominated woodland persisted throughout much of the postglacial and became more diverse at c. 7500 BP with the arrival and expansion of Carpinus orientalis/Ostrya carpinifolia. Anthropogenic intervention at c. 4500 BP was probably responsible for a reduction in the oak woodland and the formation of a vegetation type similar to present day which is dominated b}' herbaceous taxa and chew-resistant shrubs such as Quercus coccifera and Paliurus spina-christi.

Macroscopic plant remains from Mediterranean caves and rockshelters: Avenues of interpretation

“…The clear evidence of human activity in Stratum 6c, especially in the western part of the cave (trench XXI), would lend support to the interpretation that the wood charcoal in these levels is anthropogenic in origin. In Epirus, the pollen data from Ioannina (Bottema, 1974; Figure 15) and Lake Gramousti (Willis, 1992(Willis, , 1997; Figure 16) indicate that during the early post-glacial (ca. 11,000 yr B.P.)…”

“…oak and pine predominate in the sparse arboreal pollen, with maple and juniper also present, as at Konispol (Figure 15). For the period from 13,000 to 10,000 yr B.P., pollen data from Lake Gramousti at an elevation of 400 m asl (Figure 1) shows that trees were still sparse and deciduous oak and juniper would have formed an open forest or steppe-forest (Figure 16) (Willis, 1997(Willis, , 1992. Species such as almond, plane tree, buckthorn, and pistachio are barely or not at all represented in these Late Pleistocene spectra.…”

Altitudinal variation in the late quaternary vegetational history of Northwest Greece

“…Gramousti lake basin at a height of 285 m a.s.l. (Figure 2) is thought to be a feature of the karstic landscape such as a doline (Willis 1992a). It is located within the wider environs of the Doliana basin although it is a hydrologically closed basin.…”

“…Dating of the core by six AMS dates (Hedges et al 1990, Willis 1992a) revealed a sedimentary record spanning the last 14,000 years. Following a detailed study of the pollen and plant macrofossil material contained within the sediment (Willis 1992a), a pollen percentage diagram plotted against age was constructed and is presented in Figure 3.…”

“…The Gramousti lake basin was cored using a modified Livingstone piston corer (Wright 1967) and a 18.45 m core was collected (Willis 1992a). Dating of the core by six AMS dates (Hedges et al 1990, Willis 1992a) revealed a sedimentary record spanning the last 14,000 years.…”