Pollen and related studies at Kinloch, Isle of Rhum, Scotland, with particular reference to possible early human impacts on vegetation



The Inner Hebridean island of Rhum lies between the once wooded mainland of north-west Scotland and the now largely treeless islands of the Outer Hebrides. Rhum is more exposed than the nearby larger islands and is of particular interest since it has been occupied by humans for at least 8500 years. Pollen, charcoal and radiocarbon studies were carried out on a peat profile from Kinloch in the most sheltered eastern part of the island, some 300 m from the site of the earliest known Mesolithic occupation site in Scotland.

From an estimated 7800 BP, the local mire surface was open with some hazel and willow scrub. Alder replaced willow at c. 6500 BP and with hazel, remained the dominant woody vegetation until c. 4000 BP when both were reduced and by which time evidence for agriculture is discernible. A period of reduced Alnus and Corylus between 5950 and 5700 BP, with high concentrations of charcoal, may result from human influence. An Alnus reduction dated to between 5250 and 4950 BP may have been caused by changes in mire hydrology. The woodland was more open than that at nearby mainland sites but it was comparable to well-wooded sites on Skye and Mull. Birch was notably less significant at the Rhum site and the preponderance of Alnus along with persistently high Osmunda values may indicate that adaptation to exposure and salt tolerance were important factors in determining the character of the early postglacial vegetation.