A 10 000 year local forest fire history in a dry heath forest site in eastern Finland, reconstructed from charcoal layer records of a small mire

Abstract

Local fire history covering the entire Holocene period at a dry forest site in North Karelia, eastern Finland (ca. 63°07' N, 30°44' E), was reconstructed on the basis of visible charcoal layers from peat deposits of a small mire basin. Seven points studied along a transect a few metres long provided a record of ancient local forest fires that had scarred the margin of the peat deposit. The charcoal layer records indicate a drastic increase in forest fires about 500 years ago compared with the earlier part of the Holocene period. During the past 500 years, human influence has been extensive in the area, and there have been 9 local fires during that period, while during the previous 9500 years there had been only 34 fires. Between the establishment of spruce (Picea abies (L.) Karst.) 6300 calendar years B.P. and the beginning of significant human influence, the site had burned over at a mean interval of 220–260 years. The data indicate a decrease in fire frequency associated with a warm climate between 9000 and 6300 calendar years BP. This suggests that climatic warming does not necessarily result in increased frequency of forest fires.

A continuous record of fire covering the last 10,500 calendar years from southern Sweden — The role of climate and human activities

“…Finland has the longest tradition of fire studies in Europe (e.g. Tolonen, 1978;Huttunen 1980;Pitkänen and Huttunen, 1999;Pitkänen et al, 1999aPitkänen et al, ,b, 2001Pitkänen et al, , 2002. The study by Clark et al (1989) was the first entire Holocene fire record from central Europe.…”

“…Pitkänen et al, 2001Pitkänen et al, , 2002, the Holocene long-term fire history of European boreal and hemiboreal forests is still poorly known for the early and middle Holocene. Fire-scar studies covering the last ca.…”

A case study of the role of climate, humans, and ecological setting in Holocene fire history of northwestern Europe

“…Except from the detailed studies in eastern Finland (e.g., Pitkänen et al, 2001Pitkänen et al, , 2002, the early and mid-Holocene long-term fire history of European boreal and hemiboreal forests is still poorly known. In contrast, many studies of the late Holocene were undertaken and several syntheses of the late Holocene charcoal records in southern and central Scandinavia were recently published (e.g., Bradshaw et al, 2010;Ohlson et al, 2011).…”

Neolithic land use in the northern Boreal zone: high-resolution multiproxy analyses from Lake Huhdasjärvi, south-eastern Finland

“…In eastern Finland, the mean interval of 220-260 years for forest fires has been recorded at a dry forest site prior to significant human impact between 4300 bc and ad 1500 (Pitkänen et al 2002), and in central Finland, local fire history studied from a small forest hollow has shown a 430-year return period between 3000 and 1 bc (Clear et al 2013). This, in general, agrees with fire frequency on the European scale, where sedimentary charcoal records suggest only little fire activity during the Early and Middle Holocene compared to recent millennia (Molinari et al 2013).…”