The comparative use of charcoal frequency, area and morphology to reconstruct fire history in a late Holocene peat sequence from NW Romania

Abstract

Ombrotrophic peatlands are ideal archives for reconstructing charcoal fluxes resulting from vegetation burning. This is because they are sensitive to local environmental changes and the deposition of allochthonous material is exclusively atmospheric. This article presents a charcoal analysis in which two generally accepted research methods were compared, namely (i) quantification of the frequency of occurrence (number), and (ii) quantification of the size (area) of charred particles. The peat cores were extracted from the ombrotrophic bog of Tăul Mare in the Eastern Carpathian Mountains (northern Romania). The two methods for quantifying the occurrence of charcoal yielded similar results showing increasing variability of fire activity during the last ~ 3000 years. Charcoal peaks were best defined in the charcoal area dataset and indicated an increase in charcoal particle size during periods of high charcoal abundance, which points to local fires. Analysis of charcoal morphology showed that, during time intervals with high charcoal abundance, there was a gradual increase in the proportion of burnt wood. This suggests that episodes of high and/or low intensity burning, on both long and short timescales, may play an important role in determining the charcoal signature of these events. The high level of detection of high intensity fires suggests that charcoal records may be most useful in systems with high intensity fires.

Keywords

• bog
• eastern carpathians
• human activity
• ombrotrophic peatland
• tăul mare