Woodland history in the upper Harz Mountains revealed by kiln site, soil sediment and peat charcoal analyses

Charcoal is abundant in various soils and soil sediments and is basically the result of either natural wildfires or of anthropogenic ignition. Compositions of charcoal assemblages are the result of several taphonomical processes. Beside this, little is known about the influence of charcoal from anthropogenic origin, like charcoal production sites (kiln sites) on soil charcoal assemblages. To elucidate how human charcoal production as well as erosion of the relicts of kiln sites influenced charcoal assemblages in soils and mires, a multi-proxy approach was applied at two transects on the Renneckenberg, a steep slope in the low mountain range Harz, Germany. On this slope, three types of archives (soil/soil sediments, kiln sites and peatland) were investigated each with different methods on a local scale (soil charcoal analyses, kiln site charcoal analyses, peat macro-/micro-charcoal and pollen analysis). The kiln site charcoal records are taxonomically richer in wood taxa than those from colluvial assemblages, especially regarding deciduous tree species. Fagus sylvatica and Acer sp. are rare or absent in the colluvial charcoal assemblages which are dominated by Picea charcoal. At the bottom of the slope, the soil charcoal concentration is very high and indicates strong erosion of charcoal from the upper part of the slope. Significant taxonomical discrepancies between the colluvial and the kiln site charcoal assemblages may be related to different fire intensity throughout the Holocene and to human woodland usage. Additionally, changes in the run-off intensity and fire frequency are detected in the peat macro-charcoal record reflecting vegetation change in the early Holocene. The micro-charcoal content coincides with the main mining phases in the late Holocene and the 9.2 k climatic anomaly. (C) 2012 Elsevier Ltd and INQUA. All rights reserved.