An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

• Published in: Studia Quaternaria
• Main Authors: Helama, Samuli, Holopainen, Jari, Timonen, Mauri, Mielikäinen, Kari
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Walter de Gruyter GmbH 2014
• Subjects: Earth-Surface Processes; Geology; North Atlantic; North Atlantic oscillation
• Online Access: http://dx.doi.org/10.2478/squa-2014-0006; https://content.sciendo.com/view/journals/squa/31/1/article-p61.xml; https://www.degruyter.com/view/j/squa.2014.31.issue-1/squa-2014-0006/squa-2014-0006.pdf

Abstract A near-millennial tree-ring chronology (AD 1147-2000) is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L.) and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993), the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity) and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.