Recent landscape history from a Co. Down lake deposit.

A radiocarbon-dated pollen diagram from a lake deposit at a lowland site in Co. Down, Northern Ireland showed mixed agriculture had been continuous over much of the last two millennia. The introduction of cereal cultivation at between the 3rd and 5th centuries A.D. is earlier than usual at sites with heavy soils in Ireland. There was no palynological evidence to support the historical view that there had been substantial woodland clearance in the area during the 17th century. Landscape enclosure by hedges, starting in the 18th century, was detectable in the fossil pollen record. The pollen evidence for flax cultivation showed that this was relatively recent. Throughout the diagram the continual presence of Ulmus pollen demonstrated that, in contradiction of the historic view, the taxon was extant in the area throughout the period A.D. 600 to A.D. 1700.