High resolution palynological, multiple profile and radiocarbon dating studies of early human impacts and environmental change in the Inner Hebrides, Scotland
The Inner Hebrides comprise a diverse range of environments and vegetation, andarchaeological evidence suggests that people were interacting with these from early Holocene times. There are relatively few detailed palynological investigations from the islands for the early Holocene and not all the published data include quantification of microscopic charcoal which may assist in the interpretation of human impacts. Radiocarbon dates are also lacking from a number of the published profiles so that inter-site comparisons and comparisons with the archaeological record are difficult. Some pollen profiles from the Inner Hebrides contain possible indications of human impact in the first half of the Holocene (Lowe and Walker, 1986a; Andrews et al., 1987; Herons and Edwards, 1990; Edwards and Berridge, 1994). These profiles lack detail however, and it was clear that a multiple profile approach would provide a clearer picture of vegetation change and allow more confident interpretations of the pollen data. The coring of several sites would assist in defining the spatial differences in early Holocene vegetation within the islands and differences in the scale of human impacts which may reflect different types of interference. Multiple profiles were obtained from Loch a'Bhogaidh (Islay), A'Chrannag bog and Livingstone's Cave bog (Ulva) and Kinloch (Rum), all of which are close to areas of known Mesolithic occupation. A single core was obtained from Loch an t'Suidhe at Bunessan, south west Mull, from where there is currently no archaeological record for the Mesolithic. All cores were analysed for pollen and microscopic charcoal and AMS dates were obtained for all profiles. The results provide evidence for changes in vegetation due to climatic impacts and inferred Mesolithic activity. The possible effects of human influence vary from temporary woodland reductions to the creation of heathland and cereal cultivation. The use of multiple profiles is validated in that it provides an indication of spatial variation in inferred land use patterns over short timescales. The results are compared with previously published studies and the factors influencing the early Holocene spread of arboreal taxa, and the elm decline, are re-evaluated.