Mire-development pathways and palaeoclimatic records from a full Holocene peat archive at Walton Moss, Cumbria, England

Abstract

Plant macrofossil data have been used to identify the successive mire communities occupying both central and marginal locations in the Walton Moss peatland complex, during the last 10 500 years. The reconstructed pathways of mire development indicate that early-Holocene fen and fen-carr communities were succeeded by species indicative of deep mire water tables and oligotrophic conditions. The character of the fen/bog transition (FBT) is compared with similar records of peatland development from Britain and Scandinavia and with independent climate data for the early Holocene. The ‘pseudohochmoor’ of central Europe is suggested as an approximate modern analogue for the dry pioneer oligotrophic mire type and alternative explanations for its presence are explored. The first major increase in ombrotrophic Sphagna occurred at c. 7800 cal. BP. Overlying Sphagnum peats provide a continuous record of climate change, inferred from fluctuations in raised mire surface wetness. The proxy palaeoclimate record, reconstructed using Detrended Correspondence Analysis, registers wet shifts commencing at c. 7800, c. 5300, 4410–3990 (2s range), c. 3500, 3170–2860 (2s range), 2320–2040 (2s range), c. 1750, c. 1450, c. 300 and c. 100 cal. BP. This climate record is compared with a similar one from Bolton Fell Moss and spectral analysis of the time-series gives periodicities of c. 1100 years and c. 600 years between wet shifts.