Reconstructing Holocene Climate Change in Scotland Utilising Peat Stratigraphy and Tephrochronology

• Main Author: Langdon, Peter Guy
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-1999

Changes in Holocene palaeoclimates in Scotland have been reconstructed from seven sites: six ombrotrophic raised mires (Longbridge Moss, Langlands Moss, Temple Hill Moss, Shirgarton Moss, Mallachie Moss, and Craigmaud Moss) and one ombrotrophic blanket mire (Ben Gorm Moss) located across geographical and climatological gradients in Scotland. Detrended correspondence analysis (DCA) has been used to reconstruct a climatic proxy record from plant microfossil data. The testate amoebae data were subjected to a transfer function which produces quantitative reconstructed mire water table values using a calibration program (WACALIB). The results show coherent wet and dry phases over the last ca. 5000 years (ca. 7500 years at Temple Hill Moss), with the three proxy reconstructions supporting each other extremely well. Significant wet phases were identified at ca. cal. AD 1350-1550, AD 870-1150, AD 500-600, 750-940 BC, 1240-1390 BC, 1450-1630 BC, 1700-1900 BC, and ca. cal. 2200-2300 BC. Additional wet phases were recognised at Temple Hill Moss at ca. cal. 3350 BC, 3900 BC, and ca. cal. 4700 BC. Significant dry phases were documented at ca. cal. AD 920-1340, AD 350-520, and ca. cal. 540-390 BC. Correlations at the time of the Glen Garry and Hekla-4 isochrones revealed a significant difference between climatic phases in the north and south of Scotland, highlighting the possibility of asynchronous changes between northern Scotland and the rest of Britain. The local extinctions of Sphagnum imbricatum in the four sites where it previously grew occurred at different dates, but were all associated with a wet phase. Spectral analyses of the DCA and humification data revealed identical significant periodicities in both sets of data from four sites, either between 520-580 years or around 280 years.