Background and activities
DENDROCHRONOLOGYDendrochronology is a method used for studying tree-rings. The growth of trees often reflects annual variations in climate. Trees from the same species will thereby often have a matching pattern of annual tree-rings over large areas. In Norway the growth of conifers often correlates with the annual variation in summer temperature.
A warm summer normally provides a wider tree-ring than avarage, a cold summer a narrower tree-ring while an avarage summer has average growth. This will over a long period produce a tree-ring pattern unique for those years. A matching of the growth pattern from a sample with long tree-ring chronologies will thereby enable us to identify the actual period the tree was growing and thereby to perform a dendrochronological dating. If the number of tree-rings is sufficient and the outermost tree-ring is present in the sample, which can be seen if the bark is intact, dating of the felling year can be performed using dendrochronology.
The basis for dendrochronological activity is the construction of absolute tree-ring chronologies as far back in time as possible. Matching the tree-ring pattern from two samples from trees grown during the same period is called cross-matching. Matching the tre-ring pattern from a sample of unknown age to a tree-ring pattern related to calendar years performs a dating. By starting with living trees a long chronology back in time can be constructed by overlapping of successively older tree-ring series.
Before a house can be dated it is normal procedure to take samples from at least 10 different logs, and to construct a mean curve from the logs that contain a matching tree-ring pattern. This is necessary, as tree-ring growth is also sensitive to other environmental factors then climate.
As the tree-ring pattern matches the summer temperature, long tree-ring chronologies are known to contain valuable information on climate, thus giving rise to the sub-field of dendroclimatology, which studies climatic variations back in time.
Since tree-ring growth is also sensitive to many other environmental factors like pollution, geomorphological changes, river floods, etc. other sub-fields also exist, such as dendroecology, dendromorphology and dendrohydrology, which study the ecology of biotic communities, geomorphic processes and the history of flooding.
Scientific, academic and artistic work
A selection of recent journal publications, artistic productions, books, including book and report excerpts. See all publications in the database
- (2022) Regional Patterns of Late Medieval and Early Modern European Building Activity Revealed by Felling Dates. Frontiers in Ecology and Evolution. vol. 9.
- (2020) At the threshold of the Viking Age: New dendrochronological dates for the Kvalsund ship and boat bog offerings (Norway). Journal of Archaeological Science: Reports. vol. 29.
- (2019) Status Report of the Trondheim Radiocarbon Laboratory. Radiocarbon: An International Journal of Cosmogenic Isotope Research. vol. 61 (6).
- (2019) The 1953-1965 rise in atmospheric bomb 14C in central Norway. Radiocarbon: An International Journal of Cosmogenic Isotope Research. vol. 61 (6).
- (2019) Radiocarbon calibration around AD 1900 from Scots pine (Pinus sylvestris) tree rings from northern Norway. Radiocarbon: An International Journal of Cosmogenic Isotope Research. vol. 61 (6).
- (2018) Little Ice Age summer temperatures in Western Norway from a 700-year tree-ring chronology. The Holocene. vol. 28 (10).
- (2018) Tree-ring growth shows that the significant population decline in Norway began before the Black Death. Dendrochronologia. vol. 47.
- (2016) Dendrochronological analysis of 19 Norwegian grain chests. Dendrochronologia. vol. 37.
- (2015) Old World megadroughts and pluvials during the Common Era. Science Advances.
- (2014) Mineraljordlagene i Trollheimen er ikke interglasiale - var Trollheimen uten vegetasjon under istidene?. Blyttia : Norsk botanisk forenings tidsskrift. vol. 72 (4).
- (2014) Dendrokronologiske dateringer fra 2013 og 2014. Årbok - Foreningen til norske fortidsminnesmerkers bevaring. vol. 168.
- (2013) "Kvart menneske som døyr skal me føra til kyrkja og grava i heilag jord" : Kristen gravplass i myr fra tidlig middelalder. Historisk Tidsskrift (Norge). vol. 92 (2).
- (2013) Ny kunnskap om stavkirker ved måling av årringbredder på fotokopier. Årbok - Foreningen til norske fortidsminnesmerkers bevaring. vol. 167.
- (2012) Dendrokronologiske dateringer fra Østlandet. Årbok - Foreningen til norske fortidsminnesmerkers bevaring. vol. 166.
- (2011) Out of fashion and out of mind; some puzzles in building history solved by means of dendrochronology. AmS-Varia. vol. 53.
- (2010) Dendrokronologiske oppdateringer fra Oppland. Årbok - Foreningen til norske fortidsminnesmerkers bevaring. vol. 164.
- (2009) Norwegian dendrochronology; almost a victim of the Black Death. AmS-Varia. vol. 49.
- (2009) Dendrochronological dating of four chests: A surprising result. Dendrochronologia. vol. 27 (1).
- (2009) Dendrokronologiske dateringer fra Maihaugen. Årbok - Foreningen til norske fortidsminnesmerkers bevaring.
- (2008) The ‘Little Ice Age’ glacial expansion in western Scandinavia: summer temperature or winter precipitation?. Climate Dynamics. vol. 30 (7-8).