The impact of the Neolithic agricultural transition in Britain: a comparison of pollen-based land-cover and archaeological ~(14)C date-inferred population change

摘要

Britain's landscapes were substantially transformed as a result of prehistoric agricultural clearance and deforestation. This process began in the Neolithic and is recorded in multiple different "archives", notably those deriving from archaeological site excavations and from off-site pollen records. This paper assesses the extent to which these two independent sources show common trends and timing in terms of demographic and environmental change across Britain during the millennia prior to and after the appearance of the first farming communities. This period is analysed within the wider context of the 9000-3400 cal. BP time frame. We compare land-cover change aggregated from 42 pollen records employing a pseudo-biomisation approach with radiocarbon (~(14)C) date probability density functions from archaeological sites, which have been inferred to indicate shifts in population density. We also compare these results with selected palaeoclimate records in order to test alternative drivers of landscape change. At a broad geographical scale, pollen and archaeological records reveal very similar phases between 9000 and 3400 cal. BP. Following an initial demographic shift and landscape opening during the Late Mesolithic (~7600 cal. BP) conditions were stable until 6400 cal. BP. Around 6400-6000 cal. BP (MesolithiceNeolithic transition) a new phase began of forest disturbance and population increase. By 6000e5300 cal. BP early Neolithic population growth is clearly evident in the archaeological record with significant impacts on woodland cover, which is evident in the pollen record, reaching a maximum between 5700 and 5400 cal. BP. Between 5300 and 4400 cal. BP the archaeological record is inferred to indicate reduced mid-late Neolithic landscape impact, and this is matched by evidence of woodland reestablishment in the pollen record. Between 4400 and 3400 cal. BP renewed late Neolithic woodland clearance coincided with further population increase, which continued into the early Bronze Age. A very similar pattern is evident using a smaller-scale dataset from Scotland alone. Thus, rather than being slow and progressive, the initial Neolithic cultural transformation of Britain's landscape was relatively rapid and widespread; however, after several centuries of expansion, this process was halted and even reversed, before recommencing during the later 3rd millennium BC (after w4500 cal. BP). The impact of Neolithic forest clearance is clearly detectable as a driver of regional-scale mid-Holocene landscape change, alongside variations in climate. The Neolithic agricultural transition began a long process of anthropogenically-driven land-cover change in the British Isles, which has continued up until the present-day.