Development of millennium-length density chronologies for eastern and southern Europe

• Applicant: Professor Dr. Jan Esper
• Subject Area: Physical Geography
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 286662050

We intend to develop two millennium-length tree-ring maximum latewood density (MXD) chronologies, one for Eastern Europe using historical larch samples from the Tatra region in Slovakia, and one for Southern Europe using relict pine samples from the Pindus range in Greece. Skillful, annually resolved proxy records, spanning the entire past millennium, are urgently needed in these regions to support spatially resolved continental and hemispheric scale temperature reconstructions. Preliminary work on shorter MXD series revealed significant 20th century summer temperature signals justifying the development of millennium-length records in these regions. The proposal applicant is in close contact with researchers from Switzerland (Ulf Büntgen) and Sweden (Paul J. Krusic) who recently developed well-replicated tree-ring width (TRW) chronologies in the Tatra and Pindus mountains, and who are willing to share their historical and relict samples for density measurement. A Walesch X-ray densitometer has recently been established at the Department of Geography in Mainz, with the help of a "DFG Großgeräte" proposal, and is now operated by a permanently employed technician. This setup, plus the experience of the applicant to run such a laboratory and analyze the data, builds the foundation of this proposal on MXD-based reconstruction development. Our work plan includes: (i) the development and climate signal assessment of MXD chronologies from living trees along elevational transects, (ii) integration and joint detrending of MXD series from living trees with historical material (Tatra) and relict samples (Pindus), (iii) reconstruction of summer temperature variability over the past 1000+ years in Eastern and Mediterranean Europe, and (iv) joint analysis of the newly developed chronologies with existing records from Central and Northern Europe to develop a spatially resolved, continental scale temperature reconstruction. The new millennium-length MXD chronologies and underlying measurement series will be made available to the International Tree Ring Databank (ITRDB) upon publication of our findings.

• DFG Programme: Research Grants
• International Connection: Sweden, Switzerland, USA
• Cooperation Partners: Professor Dr. Ulf Büntgen; Dr. Paul Krusic; Jason Smerdon, Ph.D.