Nowadays, Norway spruce (Picea abies (L.) Karsten) occupies 20.9% of the forest area in Lithuania. Therefore, it is the second most important coniferous species in the forest economy of Lithuania.
The first results of a dendroclimatogical investigation on Norway spruce in western Lithuania were published by Irena Čerškienė (Чершкене, 1972). The comprehensive results were published in the dissertation Research on the radial growth of spruce forests in Lithuania (Чершкене, 1975) and in the book Условия среды и радиальный прирост деревъев (Чершкене, 1978). Irena Čerškienė has established that the increase in tree radial growth at all sites was observed in 1933–1934, 1948–1949, 1960–1961, and the decrease in 1920–1921, 1930–1931, 1941–1942, 1954–1955 and 1964–1965. The humidity during the vegetation season was recognised as the main factor influencing the radial growth of spruce. The impact of temperature was not observed on dry and semi-dry sites (Чершкене, 1972; 1975; 1978).
Norway spruce was revisited by J. Karpavičius (Karpavičius et al. 1996) in 1996 by using response function analysis. The study confirmed the importance of precipitation for spruce in comparison to pine.
Dendroclimatological research on 54 research plots of spruce in Lithuania was carried out by Adomas Vitas from 1996–2002 (Vitas, 2002). The investigation revealed the positive and significant influence of precipitation in March–June. In addition, the positive influence of warm January–April and the negative impact of high June–August temperature was observed for spruce radial growth (Vitas, 1998). The impact of air temperature on wet forest sites is more noticeable than that of precipitation (Vitas and Bitvinskas, 1998).
Positive and negative pointer years of Norway spruce radial growth were detected in 1903(+), 1941(–), 1946(+), 1950(+), 1954(–), 1961(+), 1962(+), 1974(+), 1979(–), 1980(–), 1983 (+), 1987(+), 1990(+), 1992(–), and 1993(–). Furthermore, results show that dry and cold springs and dry summers caused negative pointer years, while the wide tree rings were provoked by warm springs and humid summers.
A multiple regression analysis between the radial growth of spruce, air temperature and precipitation during 1930–1994.