A 781-year oak tree-ring chronology for the Middle Ages archaeological dating in Maramures (Eastern Europe)

From 1997 to the present, a sustained project in the Maramures region in Romania was completed with the construction of a 781-year oak tree-ring chronology. A total of 395 samples from living trees and 429 from archaeological wood were analysed with dendrochronological methods. The study aimed to provide the scientific community with a new oak chronology that could be applied in dendroarchaeology, dendroclimatology and dendroecology studies and also for interpreting past socio-economic events. Furthermore, we studied the number of sapwood rings and the growth pattern for different time periods. The chronology covered the continuous period of A.D. 1236-2016. From the 824 samples collected, we separated 271 tree-ring series into a new chronology (A.D. 1406-2016), which fulfilled all the criteria necessary to reconstruct past climate and environmental changes. The resulting new tree-ring chronology indicated robust signal series intercorrelation (r = 0.55) and an average mean sensitivity of 0.21. Based on an analysis of the sapwood, we recommend estimating a number between 8 and 32 rings to the date of final ring for 95% confidence range of mean on the for felling in the Maramures region. Additionally, we observed that the number of sapwood rings was not correlated with altitude or oak tree species.