Effect of Temperature on Radial Growth of Beech and Pine Saplings in the First and Second Year of the Experiment: a Comparison

Abstract

The aim of the study was to monitor the seasonal dynamics of radial growth in one to two-year old saplings of European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) under three different temperature regimes: greenhouse (G), cooling chamber (C) and outdoors (K). The research was conducted over two growing seasons, 2010 and 2011, in order to compare the effect of different environmental conditions on the radial growth of saplings in the first and second year of the treatment. The results showed that the patterns of the radial growth of beech saplings exposed to different temperature conditions were similar, especially in 2010. An increase in radial diameter was observed generally one month later in 2010 than in 2011, probably due to transplant shock in 2010. In pines, on the other hand, such delays were not recorded; however, the growth ring patterns of saplings exposed to different treatments differed in the studied growing seasons. In both years, the wood increment of beech was narrowest in G and widest in C. In 2010, xylem growth rings of pines were widest in Gand and narrowest in C, whereas in 2011 they were widest in K. Two-year xylem increments of beech saplings were lowest in G, but similar in C and K. In the case of pine, the two-year xylem increment was widest in K and narrowest in C. Comparison of xylem growth ring widths of pine and beech saplings in 2010 and 2011 under different regimes showed that widths in 2010 were wider in pines under all three regimes, whereas in 2011 increments of pines were narrower than those of beech only in C. Our fi ndings indicate different phenotypic plasticity of pine and beech saplings under different temperature regimes, in terms of radial growth. It is also clear that a continuation of such experiments over many growing seasons is necessary to capture the short- and long-term growth response of trees in changing environmental conditions.

Keywords

• Fagus sylvatica
• Pinus sylvestris
• xylem increment
• juvenile period
• temperature