A new serial pooling method of shifted tree ring blocks to construct millennia long tree ring isotope chronologies with annual resolution

Abstract

The study presents a new serial pooling method of shifted tree ring blocks for the building of isotope chronologies. This method combines the advantages of traditional ‘serial’ and ‘intertree’ pooling, and can be recommended for the construction of sub-regional long isotope chronologies with sufficient replication, and on annual resolution, especially for the case of extremely narrow tree rings. For Scots pines (Pinus sylvestris L., Khibiny Low Mountains, NW Russia) and Silver firs (Abies alba Mill., Franconia, Southern Germany), serial pooling of five consecutive tree rings seems appropriate because the species- and site-specific particularities lead to blurs of climate linkages in their tree rings for the period up to ca. five years back. An equivalent to a five-year running means that curve gained on the base annual data sets of single trees can be derived from the analysis of yearly shifted five-year blocks of consecutive tree rings, and therefore, with approximately 20% of the expense. Good coherence of δ¹³C- and δ¹⁸O-values between calculated means of annual total rings or late wood data and means of five-year blocks of consecutive total tree rings analysed experimentally on most similar material confirms this assumption.

Keywords:

• carbon-13
• dendrochronology
• oxygen-18
• palaeoclimate
• pooling
• sampling strategy

Acknowledgements

This work is funded by EC grant 017008 (GOCE; MILLENNIUM)2 and by ESF Euroclimate project ‘TREE-14’. Special thanks are due to Ms. Remmele, Ms. Trebing-Niyazi, Ms. Helmstedt and Ms. Schäfer for carrying out the ring width and stable isotope analyses. We are grateful to Ms. Marika Haupt for her kind help in using the EViews6 programme, and to two unknown reviewers who have improved this study. The main content of this paper – use of serial pooling as a new pooling method – was introduced by the authors at the ‘Millennium’ workshop in February 2007 (Mallorca, Spain) and at the ESF workshop in March 2007 (Potsdam, Germany).

Notes

; ¹³C/¹²C, ¹⁸O/¹⁶O.

‘Millennium – European climate of the last millennium’ funded as part of the EC Programme Sub-Priority 6.3 ‘Global Change and Ecosystems’.