A millennial record of environmental change in peat deposits from the Misten bog (East Belgium)

Abstract

a b s t r a c tIn this study, palaeoenvironmental changes recorded in the top metre of a peat profile (Misten bog, East Belgium) were investigated using a multiproxy approach. Proxies include bulk density, Ti and Si content, pollen, macrofossils, d13 C on specific Sphagnum stems, and d 13Ced 18O on Sphagnum leaves. A highresolution chronology was generated using 210 Pb measurements and 22 14 C AMS dates on carefully selected Sphagnum macrofossils. d 13C only records large change in mire surface wetness. This is partly due to the fact that the core was taken from the edge of a hummock, which may make it difficult to track small isotopic changes. The d 13 C signal seems to be dependent upon the Sphagnum species composition.For example, a change between Sphagnum section Cuspidata towards Sphagnum imbricatum causes a significant drop in the d 13 C values. On the whole, the C and O isotopes record two shallow pool phases during the 8the9th and the 13th centuries. Pollen and atmospheric soil dust (ASD) fluxes records increased human occupation in the area. There may be some climatic signals in the ASD flux, but they are difficult to decipher from the increasing human impact (land clearance, agriculture) during the last millennium. The variations in the proxies are not always synchronous, suggesting different triggering factors (temperature, wetness, windiness) for each proxy. This study also emphasizes that, compared to studies dealing with pollution using geochemical proxies, palaeoclimatic inferences from peat bogs need as many proxies as possible, together with highly accurate and precise age-models, in order to better understand climate variability and their consequences during the Holocene.

Deciphering human–climate interactions in an ombrotrophic peat record: REE, Nd and Pb isotope signatures of dust supplies over the last 2500years (Misten bog, Belgium)

“…6). For the Misten bog, a similar relationship between solar activity and dust flux was already suggested by De Vleeschouwer et al (2012). The potential link between enhanced distal supplies and cold climate requires further investigation as little is known about the influence of a global colder climate event on Saharan airborne particle production and transport.…”

“…However ombrotrophic bogs record both natural and anthropogenic dust supplies. For instance, based on a high resolution study on the Misten peatland De Vleeschouwer et al (2012) emphasized that variations in dust fluxes, derived from the elementary composition of the upper first meter of peat, could not be directly interpreted in term of climate changes for the late Holocene, and especially for the past millenium, where both influences are difficult to distinguish. Therefore before making any climate interpretations, the sources of dust must be identified.…”

Mid- and late Holocene dust deposition in western Europe: the Misten peat bog (Hautes Fagnes – Belgium)

“…Anthropogenic effects explaining the maximum in the Swiss peat bog do not seem to have an important effect during this period in the Misten core. Sjogren (2006) showed that the open pastures started around Etang de la Gruère bog during the first centuries BC, as shown by peat studies, but only started around Misten peatland before 850 cal BP (De Vleeschouwer et al, 2012).…”

Late Holocene ecohydrological and carbon dynamics of a UK raised bog: impact of human activity and climate change

“…Lomas-Clarke and Barber, 2007;Coombes et al, 2009;Lamentowicz et al, 2009;Schofield et al, 2010). However, studies of recent environmental change that utilise a comprehensive array of biological, geochemical and physical proxies in ombrotrophic peatlands are relatively uncommon (De Vleeschouwer et al, 2009;van der Knaap et al, 2011;De Vleeschouwer et al, 2012) The drivers of ecohydrological change in peatlands during the late Holocene become increasingly convoluted as abrupt climatic changes occur contemporaneously with elevated levels of human impact, resulting in complex palaeoenvironmental signals. Therefore a need for a fully integrated approach to palaeoenvironmental reconstructions using multiple proxy methods and empirical evidence is apparent.…”