The role of fire in southern Scandinavian forests during the late Holocene

Abstract

Charcoal fragments preserved in small, wet basins are used to characterise the fire regime of temperate and mixed boreal forest (hemiboreal) zones of southern Scandinavia during the last 3500 years. There was far less charcoal recorded from the temperate zone than the hemiboreal zone during the last 3500 years, yet the low temperate zone values showed a clear trend of continuous increase until 1500 AD, after which the values decreased sharply. The record from the hemiboreal region showed a greater temporal variability with far higher charcoal influx values than in the temperate zone. There were significant positive correlations between charcoal influx and Betula, Calluna and Pinus pollen abundance and negative correlations with pollen indicators of anthropogenic impact such as Rumex and Cerealia. Charcoal influx in the temperate zone showed a strong association with the period of major anthropogenic impact, whereas the hemiboreal data reacted more to climatic change. The temporal and spatial pattern of charcoal influx was only a minor explanatory factor for vegetation composition at a regional scale in southern Scandinavia. The fire return interval was often long and irregular in most of the region and anthropogenic factors such as grazing, mowing and establishment of arable fields were probably more important than fire as drivers of vegetation change.