Seasonal Formation of Tree Rings in Siberian Larch and Scots Pine in the Southern Taiga of Central Siberia

A comparative analysis of the seasonal formation of tree rings has been performed in Siberian larch ( Larix sibirica Ledeb.) and Scots pine ( Pinus sylvestris L.), growing in the southern taiga of Central Siberia in two sites on the altitudinal transect (200 and 536 m a.s.l.). Core samples were taken from April to September in 2012. The results have shown that the onset and duration of different phases of tree ring formation in larch and pine are determined by the geographic location of the sites and the related temperature gradient. It should be noted that species-specific features of tree growth have an effect on the formation of xylem cells during the growing period and, as a consequence, on the dimensional anatomical parameters of tracheids.