Architectural wooden monuments as a source of information for past environmental changes in Northern Russia

A pine chronology (Pinus sylvestris) for the coastal area of one of the Europeʹs largest lakes—Lake Onega is presented. Samples from living trees and from historical monuments were used. The chronology covers the period from 1550 to 2000, with at least 50 samples covering the first 300 years collected from different monuments. Time of construction was determined for three 18th century churches and one 19th century peasantʹs house. It was shown that for all monuments, the timber was logged 3–5 years before the time of building known from archival data. Research revealed that extreme low temperatures during the growing season resulted in a factor of 1.5–3 decrease in the tree ring width in 1601, 1783 and 1939–1940. In a majority of the samples, false rings induced by low temperatures in early summer are observed in 1601 and 1812. Density fluctuations of early wood are characteristic for the year 1810. For stands growing on soils with low water holding capacity and thus prone to water deficiency, variations in the width of annual rings are related to variations in rainfall. It is shown that fluctuations of the water level in Lake Onega can serve as an indicator of rainfall and, therefore ground water level. The availability of wooden structures of different ages in the museum enables objective correction of the regional chronology and a highly reliable interpretation of natural factors influencing tree growth in the region.