Change search
ReferencesLink to record
Permanent link

Direct link
Blue intensity for dendroclimatology: Should we have the blues? Experiments from Scotland
Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
Show others and affiliations
2014 (English)In: Dendrochronologia, ISSN 1125-7865, Vol. 32, no 3, 191-204 p.Article in journal (Refereed) Published
Abstract [en]

Blue intensity (BI) has the potential to provide information on past summer temperatures of a similar quality to maximum latewood density (MXD), but at a substantially reduced cost. This paper provides a methodological guide to the generation of BI data using a new and affordable BI measurement system; CooRecorder. Focussing on four sites in the Scottish Highlands from a wider network of 42 sites developed for the Scottish Pine Project, BI and MXD data from Scots pine (Pious sylvestris L.) were used to facilitate a direct comparison between these parameters. A series of experiments aimed at identifying and addressing the limitations of BI suggest that while some potential limitations exist, these can be minimised by adhering to appropriate BI generation protocols. The comparison of BI data produced using different resin-extraction methods (acetone vs. ethanol) and measurement systems (CooRecorder vs. WinDendro) indicates that comparable results can be achieved. Using samples from the same trees, a comparison of both BI and MXD with instrumental climate data revealed that overall, BI performs as well as, if not better than, MXD in reconstructing past summer temperatures (BI r(2) = 0.38-0.46; MXD r(2) = 0.34-0.35). Although reconstructions developed using BI and MXD data appeared equally robust, BI chronologies were more sensitive to the choice of detrending method due to differences in the relative trends of non-detrended raw BI and MXD data. This observation suggests that the heartwood-sapwood colour difference is not entirely removed using either acetone or ethanol chemical treatment, which may ultimately pose a potential limitation for extracting centennial and longer timescale information when using BI data from tree species that exhibit a distinct heartwood-sapwood colour difference. Additional research is required in order to develop new methods to overcome this potential limitation. However, the ease with which BI data can be produced should help justify and recognise the role of this parameter as a potential alternative to MXD, particularly when MXD generation may be impractical or unfeasible for financial or other reasons.

Place, publisher, year, edition, pages
2014. Vol. 32, no 3, 191-204 p.
Keyword [en]
Blue intensity, Maximum latewood density, Scots pine, Dendroclimatology, Image analysis, Scotland
National Category
Earth and Related Environmental Sciences
URN: urn:nbn:se:su:diva-110148DOI: 10.1016/j.dendro.2014.04.003ISI: 000344435300003OAI: diva2:771491


Available from: 2014-12-14 Created: 2014-12-08 Last updated: 2014-12-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
McGlynn, LauraGunnarson, Björn E.
By organisation
Department of Physical Geography and Quaternary Geology
In the same journal
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 27 hits
ReferencesLink to record
Permanent link

Direct link