Growth and survival of Norway spruce in the provenance experiment IUFRO 1972 at the age of 38 year | Rast a prežívanie smreka na plochách provenienčného pokusu IUFRO 1972 vo veku 38 rokov

Norway spruce (Picea abies L.) belongs to tree species with the largest distribution range and the biggest economical importance. At the same time, it is one of the most endangered by climate change. A considerable diversity od its natural environments has led to the formation of genetically differentiated populations, exhibiting different morphology, physiology and yield. For the assessment of the genetic background of these differences, provenance trials are commonly used, representing common garden tests established by reproductive materials of different origins. The international provenance experiment IUFRO 1972 includes in Slovakia 5 parallel plots distributed along an elevational gradient from 350 to 1000 m a.s.l. with 30 provenances, mainly of Polish and Slovakian origin. Earlier assessments of this provenance experiment (PACALAJ et al. 2002, KRAJMEROV A et al. 2009), demonstrated that the Carpathian spruce provenances adapt better to the local environments, especially when compared to provenances originating from central and northern Poland and the Sudetes. West-Carpathian provenances exhibited a significant GxE interaction or showed good growth on all testing sites. The response of Polish and Hercynic provenances to the transfer to new environments was generally unbalanced and unpredictable. The most adaptable provenances originated especially from lower altitudes and southern part of spruce range in the Western Carpathians. They react by improved growth and survival on the transfer to warmer sites with longer vegetation seasons and nutrient-rich soils, whereby they tolerate seasonal lack of precipitation. High-elevation provenances and provenances from northern and eastern Poland performed well at higher altitudes with moist and cold climates. Local Western Carpathians provenances belong thus to the best ones, even in more extreme sites and under climate change. Most of them originate from lower elevations. Under climate change, their source populations need to be conserved also using active ex situ measures such as seed stands and regional seed orchards.