Minimum blue intensity measurements of resin-extracted Pinus sylvestris (L.) samples, conducted using a flat-bed scanner and commercially available software, are shown to provide a robust and reliable surrogate for maximum latewood density. Blue intensity data from 15 trees, from three stands, are reported relative to a standard blue-scale in a manner similar to grey-scale calibration in x-ray densitometry. The resulting time series are highly correlated with x-ray densitometry data generated from the same samples and preserve the same high level of signal strength. Sensitivity to summer climate variables is similar to that identified in the relative density record, demonstrating that minimum blue intensity can also be used for the study of climate change. While not a replacement for the powerful range of x-ray densitometry techniques, blue intensity provides an inexpensive and accessible alternative for accessing palaeoclimatic information.
Andersson, N.A. , Callaghan, T.V. and Karlsson, P.S.1996: The Abisko Scientific Research Station . Ecological Bulletins45, 11—14 .
2.
Bergsten, U. , Lindeberg, J. , Rindby, A. and Evans, R.2001: Batch measurements of wood density on intact or prepared drill cores using x-ray microdensitometry . Wood Sciences and Technology35, 435—452 .
3.
Briffa, K.R. , Jones, P.D. and Schweingruber, F.H.1988: Summer temperature patterns over Europe: a reconstruction from 1750 AD based on maximum latewood density indices of conifers . Quaternary Research30, 36—52 .
4.
Briffa, K.R. , Jones, P.D. , Schweingruber, F.H. , Shiyatov, S.G. and Cook, E.R.2002: Unusual twentieth-century summer warmth in a 1,000-year temperature record from Siberia . Nature376, 156—59 .
5.
Cleaveland, M.K.1986: Climatic response of densitometric properties in semiarid site tree-rings . Tree-ring Bulletin46, 13—29 .
6.
Cook, E.R. and Holmes, R.L.1986: Users manual for computer program ARSTAN . In Holmes, R.L., Adams, R.K. and Fritts, H.C., editors, Tree-ring chronologies of western North America: California, eastern Oregon and northern Great Basin . Chronology Ser 6. University of Arizona , 50—56 .
7.
Cook, E.R. and Kairiukstis, L. , editors 1990: Methods of dendrochronology: applications in environmental sciences. Kluwer Academic Publishers .
8.
Eronen, M. , Zetterberg, P. , Briffa, K.R. , Lindholm, M. , Merilainen, J. and Timonen, M.2002: The supra-long Scots pine tree-ring record for Finnish Lapland: part 1, chronology construction and initial inferences . The Holocene12, 673—81 .
9.
Fritts, H.1976: Tree rings and climate. Academic Press .
10.
Gindl, W. , Grabner, M. and Wimmer, R.2000: The influence of temperature on latewood lignin content in treeline Norway spruce compared with maximum density and ring width . Trees — Structure and Function14, 409—14 .
11.
González, I.G. and Eckstein, D.2003: Climatic signal of early wood vessels of oak on a maritime site . Tree Physiology23, 497—504 .
12.
Grudd, H. , Briffa, K. , Karlén, W. , Bartholin, T.S. , Jones, P.D. and Kromer, B.2002: A 7400-year tree-ring chronology in northern Swedish Lapland: natural climatic variability expressed on annual to millennial timescales . The Holocene12, 657—67 .
13.
Holmes, R.L.1999: Users manual for program COFECHA. Laboratory of Tree-Ring Research , University of Arizona .
14.
Laroque, C.P. and Smith, D.J.2005: Predicted short-term radial-growth changes of trees based on past climate on Vancouver Island, British Columbia . Dendrochronologia22, 163—68 .
15.
Lenz, O. , Schär, E. and Schweingruber, F.H.1976: Methodische Probleme bei der radiographisch-densitometrischen Bestimmung der Dichte und der Jahrringbreiten von Holz . Holzforschung30, 114—23 .
16.
Loader, N.J. , Robertson, I. and McCarroll, D. 2003: Comparison of stable carbon isotope ratios in the wholewood, cellulose and lignin of oak tree-rings . Palaeogeography, Palaeoclimatology, Palaeoecology196, 395—407 .
17.
McCarroll, D. and Loader, N.J.2004: Stable isotopes in tree-rings . Quaternary Science Reviews23, 771—801 .
18.
McCarroll, D. , Pettigrew, E. , Luckman, A. , Guibal, F. and Edouard, J.L.2002: Blue reflectance provides a surrogate for latewood density of high-latitude pine tree-rings. Arctic , Antarctic and Alpine Research34, 450—53 .
19.
McCarroll, D. , Jalkanen, R. , Hicks, S. , Tuovinen, M. , Gagen, M. , Pawellek, F. , Eckstein, D. , Schmitt, U. , Autio, J. and Heikkinen, O.2003: Multiproxy dendroclimatology: a pilot study in northern Finland . The Holocene13, 829—38 .
20.
Parker, M.L. and Henoch, W.E.S.1971: The use of Engelmann spruce latewood density for dendrochronological purposes . Canadian Journal of Forest Research1, 90—98 .
21.
Sarén, M.P. , Serimaa, R. , Andersson, S. , Saranpää, P. , Keckes, J. and Fratzl, P.2004: Effect of growth rate on mean microfibril angle and cross-sectional shape of tracheids of Norway spruce . Trees — Structure and Function18, 354—62 .
22.
Sauter, U.H. , Mutz, R. and Munro, B.D.1999: Determining juvenile-mature wood transition in Scots pine using latewood density. Wood and FibreScience31, 416—25 .
23.
Schweingruber, F.H. , Fritts, H.C. , Bräker, O.U. , Drew, L.G. and Schär, E.1978: The X-ray technique as applied to dendroclimatology . Tree-Ring Bulletin38, 61—91 .
24.
Schweingruber, F.H. , Bartholin, T. , Schär, E. and Briffa, K.R.1988: Radiodensitometric-dendroclimatological conifer chronologies from Lapland (Scandinavia) and the Alps (Switzerland) . Boreas17, 559—66 .
25.
Seth, M.K. and Jain, K.K.1978: Percentage of compression wood and specific gravity in blue pine (Pinus wallichiana A.B. Jackson) . Wood Science and Technology12, 17—24 .
26.
Sheppard, P.R. and Singavarapu, S.Y.2006: Solving the `magnification irony' in reflected-light image analysis of conifer tree-rings using a microscope. Journal of ImagingScience and Technology50, 304—308 .
27.
Sheppard, P.R. , Graumlich, L.J. and Conkey, L.E.1996: Reflected-light image analysis of conifer tree-rings for reconstructing climate . The Holocene6, 62—68 .
28.
Silkin, P.P. and Kirdyanov, A.V.2003: The relationship between variability of cell wall mass of early wood and latewood tracheids in larch tree-rings, the rate of tree-ring growth and climatic changes . Holzforschung57, 1—7 .
29.
Wigley, T.M.L. , Briffa, K.R. and Jones, P.D.1984: On the average value of correlated time series, with applications in dendroclimatology and hydrometeorology . Journal of Applied Meteorology23, 201—13 .
