An archaeobotanical investigation of Oakbank crannog, a prehistoric lake dwelling in Loch Tay, the Scottish Highlands
Oakbank crannog is a Late Bronze/Early Iron Age lake dwelling in Loch Tay, Scotland. The initial free-standing pile construction was rebuilt several times, resulting in an organic mound. The latest remaining consolidation phase incorporated large boulders which sealed the organic material underneath and preserved waterlogged remains of the plants utilised by earlier inhabitants. The base-rich soil of the local environment around the dwelling supported a mixed oak woodland with alder carr in the wetter areas and fringing the loch. Parts of this were cleared for agriculture by the earliest settlers, and woodland trees were utilised to build the dwelling, most especially alder, but also frequently oak, hazel and birch, with others occasionally at low levels. Cereal crops grown included Hordeum vulgare, Triticum dicoccum and T. spelta. Spelt wheat implies trade links with the south of the country or abroad. Linum usitatissiumum was cultivated on a small scale, possibly together with Papaver somniferum, another species which has implications for trade. The abundance of crop contaminant weed species emphasises the soil fertility, and suggests that cereal crops were neither weeded nor hand-picked on the ear. Seeds of low growing weeds indicate harvesting close to ground level. Processing was done for immediate use, at the doorway to the dwelling itself. Crop by-products including chaff and weed seeds were fed to livestock to supplement fodder. Tail grain and some prime barley may have been added or left intentionally during processing to supplement the feed. This generous use of valuable grain and edible weed seeds implies a healthy economy with adequate stores of food. Livestock were housed in the dwelling at least periodically, but were confined to specific areas.