Variation in shoot elongation patterns in Pinus contorta and Pinus sylvestris in north-west Russia

Abstract

A phenological study of six lodgepole pine populations from Swedish seed orchards and one local Scots pine population was performed in a field trial located in Komi Republic (northern Russia) (61°40′ N, 51°03′ E, 132 m a.s.l.) at the age of 5 years. The species differences in annual shoot elongation, growth onset and cessation were significant (p<0.05). The annual growth of undamaged leader shoots varied considerably among the populations and the mean shoot length was 315 mm (range 291–333 mm) for lodgepole pine and 215 mm for Scots pine seedlings. The growth rate was also higher for lodgepole pine but this difference was not statistically significant. Lodgepole pine generally had earlier onset and later cessation of shoot elongation than Scots pine. The northern lodgepole pine populations tended to initiate and cease growth earlier than southern ones but these differences were insignificant.