Result of the 35 years provenance experiment with Scots pine from the IUFRO 1982 series on the trials in Wyszkow and Sekocin

Scots pine is the main forest tree species in Poland. In this study we investigated variation in growth among 20 populations at two common−garden sites of the IUFRO 1982 provenance experimental series after 35 years of growth. The sites managed by the Forest Research Institute are located in Wyszków and Sękocin (central Poland). Populations show great diversity in the productivity and stem straightness depending on the geographical origin. The character of variability confirms the results obtained on other experimental plots established within the IUFRO 1982 series. In terms of growth, populations such as: Pornóapáti, Ardennes, Haguenau, Neuhaus as well as Miłomłyn, Rychtal and Bolewice are the best. Populations from the south of Europe grow in Polish conditions very poorly and have a low survival rate. Some of the well−growing populations (Ardennes, Pornóapáti and Haguenau) probably comes from selected stands or seed orchard. Stabilization of ranging for the best and worst populations can be observed after 15 years of growth (fig. 1). It follows that in growing experiments, conclusions about the breeding value can be drawn after 15 years. Polish populations such as Miłomłyn, Rychtal and Bolewice are growing very well and can be the basis for further selection work. Obtained results can be used for future breeding, forest genetic resources conservation and also for the other research like dendrochronology and better estimation of the seed transfer rules of forest reproductive material