Beech provenance trail in Sweden : growth and timber quality evaluation

Sammanfattning: Provenance trails allow to test tree growth differences and meet current requirements for timber quality in a particular experimental site. The aim of this manuscript was to distinguish the differences in growth and timber quality features between European beech (Fagus sylvatica L.) provenances at its natural northern European margin – in southern Sweden. Data was obtained from a provenance experiment established in 1995 in Rånna to evaluate the growth and timber quality features of 36 European beech provenances. Statistical analysis was conducted using generalized and linear mixed models, and a post-hoc Tuckey´s test to check provenance differences on quantitative (diameter at breast height, tree basal area increment, height increment, total height) and qualitative features (crookedness, classification of stem morphology, spike knots above 0.5 meters and below 0.5 meters). Results show, that the German provenance number 37 (Deister, Lower Saxony) reached the best growth outputs in following variables: diameter at breast height 2020, basal area increment, height increment and total height. German provenance number 39 (Seelzerthurm, Lower Saxony) shows the absolute best performance within classification of stem morphology and within spike knots below 0.5 meters abundance. Romanian Provenance number 150 (Sovata (25)) accomplished the best results within crookedness and spike knots above 0.5 meters abundance. German provenance number 51 (Eitorf 1502/262a – North-Rhine-Whestfalia) was evaluated worst in the following tree characteristics: crookedness, classification of stem morphology and spike knots below 0.5 meters abundance. Swedish and Danish beech provenances showed stable growth without any relevantly negative timber quality features, although they did not differ significantly from other provenances in their growth. The results demonstrate that the genetic background of studied provenances has an important role in building stand development for numerous timber quality features. New provenance experiments establishment may better understand different provenances responses to the climate change as well as to determine the best provenance for high quality timber on the Swedish market.