Siberian Federal University

For the recent years Krasnoyarsk researchers have been developing a large spatial network of dendroclimatic stations and studying millennial tree-ring chronologies in the North Eurasia. The research work is aimed at the detailed analysis of the past climate changes and their affects on the nature and society.

As Dr. Eugene Vaganov, Rector of Siberian Federal University, Member of the Russian Academy of Sciences, says, tree-rings are a unique source of information about the past climate changes, forest fires, insect outbreaks and other events in natural ecosystems.

«The two recent years have been the most fruitful and we have gained the research outcomes of the global significance. First, on millennial tree-ring chronology we have managed to identify a unique historic period (536-547 years of the first millennium) with extreme volcanic activity and minimal solar activity that was fixed by other methods. That period was identified in the northern latitudes of Asia (Taymyr and North-East of Yakutia) as well as in its continental part (Altay –Sayan highlands). The network of continental millennial chronologies in Russia that show long-term changes in summer temperature allows comparing them with the changes in Austrian Alps — says Dr. Vaganov. — Those geographically remote reconstructions of climate changes have revealed a significant similarity in long-term changes of summer temperature and allowed identifying the period from 536 to 660 of the first millennium as a unique historic period. Besides, that period is connected with important events in the history of the civilization and movement of vegetation zones».

The researchers notes that the scientific work of the same importance has been done in cooperation with the overseas partners to reveal contemporary tendencies in tree-ring growth as the indicators of temperature and precipitation changes in the comparative analysis of the long-term tree-ring chronologies on the territory of Siberia and Mediterranean area. It has been proved that in the contemporary warming conditions the synchronism in tree growth changes that took place on vast areas increases. The researchers suppose that in northern forests it was connected with the earlier growth season start and tree-ring formation as temperature increase consequence, while in the Mediterranean area it was determined by the earlier tree growth start as well as by its rough limitation due to increasing drought. The SibFU dendrochronology school representatives and their international partners are sure that the results ained is a good preliminary signal of climate changes in the sub-continental scale.

We would like to add that to do research in tree growth response in various parts of the World Siberian scientists have developed an original process-based imitation model. The model allows understanding the preliminary mechanisms of climatic factors influence on seasonal tree-ring formation and their structure and it is a reliable forecasting instrument. Besides, anatomic tree-ring structure is an imprint of a certain season, and it means certain meteorological conditions when the tree-rings were formed. The combination of anatomic measurements and modeling provides the researchers with additional information about climate changes with high time resolution , the information that is impossible to get from other sources.