Dendrochronology is the science of dating tree rings.

It includes investigations of the information content in the structure of dated rings and applications to environmental and historical questions (Kaennel & Schweingruber, 1995, Multilingual glossary of dendrochronology).

The trees (in our climate zone) every year produce a tree ring (also called growth ring, annual ring or growth layer).

Terminal ring (waney edge, German “Waldkante”) is the last ring below the bark.

Example of a tree, with the terminal ring formed in 2001.

Wood for investigations can be obtained from trees or constructions by coring.

The cores are processed so that their microscopic structure can be clearly seen under a stereo microscope.

Measurement. In most cases we measure tree ring widths.

Measuring equipment generally consists of a stereo-microscope and a measuring table connected to a personal computer with programme for data acquisition and processing.

Tree-ring series - a graph representing tree-ring widths vs. time.

Undated tree-ring series. Relative year does not represent a calendar year of a ring formation.

The trees of the same species from the same site generally show similar tree-ring patterns. We can cross-date or synchronize them.

When we want to date wood of unknown origin we can cross-date it with a reference chronology.

A chronology of an object (green curve) cross-dated with a reference chronology (red line). Date end is 1953.

Long reference chronologies are usually composed of chronologies of trees prolonged with chronologies of historical objects.

Example: local chronology of silver fir (Abies alba) from Pohorje, NE Slovenia (details in graduation thesis Stopajnik 1997 and article Levanic & Cufar Zbornik gozdarstva in lesarstva, 1998).

Teleconnection represents synchronisation of chronologies from distant sites. The European fir has a good teleconnection.

The chronologies from Pohorje (NE Slovenia) have similar tree-ring patterns as chronologies from a Dinaric region (SW Slovenia). The two regions belong to different phytogeographical regions with different climate, soil, vegetation type etc.

Chronologies are constructed for different wood species, geographical regions and periods.

Local chronologies are composed from site chronologies within a locality.

Regional chronologies are composed of several local chronologies and are generally representative for a wood species from a larger region.

Picture - origin of wood from trees and historic buildings to compose a regional larch (Larix decidua) chronology representative for Slovenia and NE Italy.

Time spans of chronologies of trees and buildings and a resulting 1242 years long regional chronology of larch for Slovenia and NE Italy. (Details in Levanic, Pignatelli, Cufar Dendrochronologia, 2001).

Selected references (please write us if you are interested to receive a reprint):

1. ČUFAR, Katarina, LEVANIČ, Tom, ZUPANČIČ, Martin. Slovenija, regija za dendrokronološke raziskave. Les (Ljublj.), 1995, let. 47, št. 5, str.133-136.

2. LEVANIČ, Tom, ČUFAR, Katarina, ZUPANČIČ, Martin. Kronologija letnih prirastkov jelke in smreke v Sloveniji. Les (Ljublj.), 1995, let. 47, št. 9, str.259-261.

3. LEVANIČ, Tom, ČUFAR, Katarina. Primerjava standardnih kronologij jelke (Abies alba Mill.) v dinarski fitogeografski regiji Slovenije = Comparision of standard chronologies of silver fir (Abies alba Mill.) in Dinaric phytogeografical region in Slovenia. Zb. gozd. lesar., 1995, št. 46, str. 131-144.

4. LEVANIČ, Tom, ČUFAR, Katarina, HUDOLIN, Jernej, BENKO-MÄCHTIG, Beta. Dendrokronološka analiza strešne konstrukcije župne cerkve sv. Jurija v Piranu (občina Piran, Slovenija) = Dendrochronological analysis of the roof construction of the church of st. George in Piran (municipality of Piran, Slovenia). Ann, Ser. hist. sociol., 1997, let. VII, št. 10, str. 43-52.

5. LEVANIČ, Tom, ČUFAR, Katarina. Construction of a Slovene Dinaric silver fir (Abies alba Mill.) regional chronology. Dendrochronologia (Verona), 1997, no. 15, str. 183-190.

6. SCHICHLER, Brigit, LEVANIČ, Tom, ČUFAR, Katarina, ECKSTEIN, Dieter. Climate-growth relationship of fir in the Dinaric mountains in Slovenia using different standarizations and response function calculations. Dendrochronologia (Verona), 1997, no. 15, str. 207-214.

7. ČUFAR, Katarina, LEVANIČ, Tom. Referencne kronologije za dendrokronološko datiranje v Sloveniji - stanje 1997 = Reference chronologies for dendrochronological dating in Slovenia - their state of development in 1997. Arheol. vestn., 1998, let. 49, str. 63-73, preglednice, zvd.

8. ČUFAR, Katarina, LEVANIČ, Tom. Progress of dendrochronological research in Slovenia. Dendrochronologia (Verona), 1998-1999, 16/17, str. 173-181.

9. LEVANIČ, Tom, ČUFAR, Katarina. The chronology of the silver fir (Abies alba Mill.) from Pohorje, Slovenia = Kronologija jelke (Abies alba Mill.) za območje Pohorja. Zb. gozd. lesar., 1998, 55, str. 135-149.

10. LEVANIČ, Tom, ČUFAR, Katarina, GUŠTIN, Božidar, TOMŠIČ, Daniela. Dendrokronološka analiza cerkve sv. Marije Alietske in kompleksa hiše Manzioli v Izoli. Ann, Ser. hist. sociol., 1999, let. 9, št. 2=18, str. 479-488.

11. ČUFAR, Katarina, LEVANIČ, Tom. Tree-ring investigations in oak and ash from different sites in Slovenia. Phyton (Horn), 1999, vol. 39, fasc. 3, str. 113-116.

12. SMITH, Kevin T., ČUFAR, Katarina, LEVANIČ, Tom. Temporal stability and dendroclimatology in silver fir and red spruce. Phyton (Horn), 1999, vol. 39, fasc. 3, str. 117-122.

13. ČUFAR, Katarina, LEVANIČ, Tom. Dendrokronologija kot metoda za datiranje lesa = Dendrochronology as a method for dating wood. V: Les v restavratorstvu, (RES., Dela, = Papers, 4). Ljubljana: Restavratorski center Republike Slovenije, 2000, str. 31-37.

14. LEVANIČ, Tom, ČUFAR, Katarina. Dendrokronološko datiranje objektov v Sloveniji = Dendrochronological dating of wooden objects in Slovenia. V: Les v restavratorstvu, (RES., Dela, = Papers, 4). Ljubljana: Restavratorski center Republike Slovenije, 2000, str. 38-47.

15. ZUPANČIČ, Martin, ČUFAR, Katarina. Determinacija lesa predmetov kulturne dediščine = Wood identification in objects of cultural heritage. V: Les v restavratorstvu, (RES., Dela, = Papers, 4). Ljubljana: Restavratorski center Republike Slovenije, 2000, str. 48-52.

16. RAVENTÓS, José, DE LUÍS, Martín, GRAS, María Jesús, ČUFAR, Katarina, GONZÁLES-HIDALGO, José-Carlos, BONET, Andreu, SÁNCHEZ, Juhan Rafael. Growth of Pinus pinea and Pinus halepensis as affected by dryness, marine spray and land use changes in a Mediterranean semiarid ecosystem. Dendrochronologia (Verona), 2001, 19, 2, str. 211-220.

17. LEVANIČ, Tom, PIGNATELLI, Olivia, ČUFAR, Katarina. A regional larch chronology of trees and historical buildings from Slovenia and Northern Italy. Dendrochronologia (Verona), 2001, 19, 2, str. 221-229.