Pollen, charcoal and stomatal evidence was examined in four Holocene lake sediment sequences at sites located throughout the Scottish Highlands in order to assess both the hypothesised mid Holocene ‘pine decline’ in the region and the apparently anomalous Holocene pattern of spread of the species. Four new Holocene pollen and charcoal sequences have been obtained in geographic areas and at topographic positions from which information is currently lacking. Examination of these and existing palynological evidence from 64 radiocarbon-dated sites in Scotland indicates that there was no abrupt, synchronous regional decline of Pinus sylvestris in the Highlands. Decreasing pine population abundance is erratic in both space and time and appears to be the result of the interaction of numerous factors and individualistic species’ tolerances. Contributing factors include competition from broadleaved species, human impact and the spread of blanket peat. Macroscopic and microscopic charcoal results indicate that pine abundance in the Highlands is not related to fire history.

Stomatal evidence reveals that pine may be locally present in an area for up to thousands of years before significant frequencies are registered in the pollen record. Pine stomata occurred in sediments with such low associated pollen frequencies, however, that no definitive minimum frequency threshold indicative of local species presence could be established. A revised Holocene pattern of spread of Pinus sylvestris, based on the examination of different minimum pollen frequency thresholds, indicates that the species may have spread rapidly throughout the Highlands in low abundance during the early Holocene, followed by a patchy pattern of population increase throughout the area, as favourable site conditions became available.

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