Something old, something new, something borrowed: New insights to human-environment interaction in medieval Novgorod inferred from tree rings

- Modern tree-ring data is used to update the archaeological chronologies for Novgorod.
- New data on the climate-society nexus is created by our temperature reconstruction.
- Tree rings agree with historical data to indicate coinciding changes in resilience.
- Frosts and crop failures disappeared with less frequent cold extremes since 1300 CE.
- The pan-European Great Famine (1315-1322 CE) did not probably extent into NW Russia.

Updating archaeological tree-ring collections for calibrations and verifications with instrumental data is an essential step in 'updating' also our understanding of the climate signals in archaeological tree-ring data. Here we delve into the Novgorod tree-ring archives by supplementing the classical medieval chronology with tree-ring data from recently harvested timber. A large, random set of saw logs from the region of archaeological site, hypothetically mimicking the sampling of archaeological timber by medieval people, was used instead of conventional sampling by dendrochronologists on carefully selected sites, to enhance the reciprocal comparability of the datasets. Our tree-ring chronologies provide calibration data explaining 32% of variance in observed February-May temperature and, along with archaeological tree-ring data, a new temperature reconstruction over the medieval period 1160-1416 CE. In the context of the agricultural subsistence economy, we found indications of altering resilience to argue that changes from generally shorter to longer recurrence interval of frost and crop failure events from early (pre-1300) to late (post-1300) period, evident in historical-documentary sources, corresponds with tree-ring evidence. Decreasing amplitude of cool events and growth curtailments and increasing growth rates from early to late period demonstrate long-term change in climate conditions becoming more favorable to agricultural subsistence economy, with implication that the pan-European Great Famine (1315-1322 CE) did not probably extent into NW Russia. Tree-ring data provide means beyond the dating of wooden objects, relevant to the ways in which archaeologists, historians and natural scientists may collaborate in the study of past climate-society nexus.