%0 Research article
%T Growth rate and wood properties of Norway spruce cutting clones on different sites
%A Raiskila, Sanni
%A Saranpää, Pekka
%A Fagerstedt, Kurt
%A Laakso, Tapio
%A Löija, Mia
%A Mahlberg, Riitta
%A Paajanen, Leena
%A Ritschkoff, Anne-Christine
%D 2006
%J Silva Fennica
%V 40
%N 2
%R doi:10.14214/sf.341
%U https://silvafennica.fi/article/341
%X The effect of growth rate on weight density and strength properties of  three Norway spruce cutting clones growing on three different sites in  different geographic locations was studied. The purpose was to follow  variation in wood physical and mechanical properties and in quality  between fast-growing clones grown in environments differing in  nutritional and soil properties and climate within the boreal zone. The  cloned trees had been selected on grounds of good growth, health and  quality. The cuttings were collected from three-year-old seedlings and  rooted. The rooted cuttings were planted in the 1970’s and they were on  average 26 years old at a time of felling. The variation of weight  density was studied within the annual ring and within the stem between  the juvenile and mature wood from the pith to the bark with an X-ray  densitometric method. The average annual ring width (and latewood  proportion, %) varied between the clones from 2.92±1.36 mm (15.34%) to  3.30±1.25 mm (11.80%) and between the sites from 2.76±1.07 mm (14.71%)  to 3.70±1.22 mm (13.29%). The mean weight density was 0.461±0.077 g cm–3  and latewood density 0.750±0.125 g cm–3 in this material. The mean  modulus of elasticity was 9.88±1.43 GPa, modulus of rupture 67.51±11.50  MPa and weight density of the test samples (ρ12) 414±44 kg m–3 in mature  wood. The parameters studied showed clearly that the environment had a  large effect while the three clones differed from each other similarly  in the different sites, e.g. the fastest growing clone was fastest on  all sites.