Early and Middle‐Flandrian pollen zonation in the Eastern Highlands of Scotland

A review is presented of published data on Early and Middle‐Flandrian pollen zones recorded at various sites in the Eastern Highlands of Scotland. This reveals a number of screpancies from site to site, particularly with regard to the position and timing both of the Pine expansion, and the Alnus‐ rise. On Deeside, Pine‐Birch forests appear to have been established before the main expansion of Alder, which occurs on Upper Deeside in the period following 6700 B.P. On Speyside, evidence is conflicting, suggesting either that the arrival of Pine and Alder took place almost synchronously about 7000 B.P., or that, as on Deeside, Pine‐Birch forest establishment preceded the main Alnus‐ rise, dated at Loch Garten at about 5900 B.P. In addition, the rate of immigration of Pine recorded at silcs of close proximily appears to vary quite markedly. Evidence from two further Speyside diagrams confirms the second view, and also shows that a gradual expansion of Pinus values took place during the period 8000‐6600 B.P., with the Alnus ‐risc delayed until 5500 B.P. Discrepancies in the records of Early and Middle‐Flandrian pollen zones from site to site are then explained in terms of differential accumulation rates, and the theory that the phase of expansion of the Pine in the Eastern Highlands took place during a period of low or falling water‐levels.