Bulletin of the Geological Society of Finland (Jun 1991)

Comparison of two methods of counting microscopic charcoal particles in peat

  • K. Sarmaja-Korjonen

DOI
https://doi.org/10.17741/bgsf/63.1.004
Journal volume & issue
Vol. 63, no. 1
pp. 41 – 48

Abstract

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A peat monolith of the topmost 92.5 cm of Slåttmossen, a bog in Helsinki/Vantaa, S Finland, was analysed for microscopic charcoal with two methods. In the first, the number of charcoal particles was counted, irrespective of their size; in the second, the total area of charcoal was calculated in seven size classes. The peat monolith was also analysed for pollen. The results show that human activity has played an important role in vegetation changes at the site and has also influenced the fire regime, as new land for cultivation was cleared with fire up to the 18th century. The ratio for charcoal and arboreal pollen concentrations was calculated to eliminate the effect of concentration peaks in the more humified peat layers. After these corrections, both methods gave almost identical results; the size class method was not superior in any way. The distribution of larger charcoal particles provided no clear evidence of individual fires nearby.

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