Late-Holocene multi-proxy climate records for Northern Britain and Ireland derived from raised peat stratigraphy

Climatic records have been obtained from five ombrotrophic raised peat bogs in Northern Britain (Heathwaite Moss, Killorn Moss and Tore Hill Moss) and Ireland (Ardkill Moss and Cloonoolish Moss). These records cover the last 2500 years, apart from Heathwaite Moss, which spans the period from ca. cal. 2500 BC to 500 AD. These proxy records were produced using three main bog surface wetness reconstruction techniques, including plant macrofossil, humification, and testate amoebae analyses. Evidence of Little Ice Age deterioration is noted at ca. cal 1730 (Ardkill Moss) and 1640 AD (Killorn Moss and Tore Hill Moss). Wet shifts are recorded after a period of dryness within the Roman period at four sites and these occur at ca. cal. 450 and 440 AD (Cloonoolish and Tore Hill Moss) and ca. cal. 280 AD and 260 AD (Ardkill Moss and Killorn Moss). All sites apart from Killorn Moss show evidence for synchronous wet shifts between ca. cal. 10-75 AD. Heathwaite, Killorn and Tore Hill Moss all show a further wet shifts initiating between ca. cal. 400-510 BC. The oldest and longest record at Heathwaite Moss also displays wet shifts at ca. cal. 2100 BC, 1500 BC, and 1030 BC. Prominent dry phases were recorded at most sites between ca. cal. 900-1150 AD (possibly relating to the Medieval Warm Period), ca. cal. 0-440 AD (Roman period) and dry shifts at ca. cal. 590 and 630 AD (Cloonoolish and Killorn Moss). Tore Hill Moss and Heathwaite Moss record a dry phase ca. cal. 760-550 BC and 930-560 BC respectively. Heathwaite Moss also displays dry shifts at ca. cal. 2300, 2100 and 1300 BC. Cycles relating to climate change were recorded at 200-300, 350 and 500-700 years in duration possibly relating to the influence of NADW production and solar activity. The decline of Sphagnum imbricatum was recorded at three sites and has been linked to increases in bog surface wetness. Problems with the techniques used such as species dependent decay, insensitive macrofossil species, and the decay of testate amoebae with depth, are also examined and their influence assessed.