Tree breeders worldwide have highlighted the importance of wood quality within the juvenile core in determining final timber strength. The potential for improving timber strength by estimating genetic parameters of certain wood properties of Sitka spruce (Picea sitchensis) within the outer zone of the juvenile core was investigated. Fifteen trees were sampled from each of 33 families selected from a 20 year old open pollinated progeny trial. A number of wood properties critical to wood strength were measured; namely, density, grain angle, microfibril angle and branching characteristics. Clearwood stiffness and strength along with indirect measures of stiffness using acoustics and density using Pilodyn measurements were assessed. All wood properties were moderately heritable, wood density and acoustic velocity were the most heritable traits (h2 i 0.71 and 0.67 respectively). Genetic correlations showed that wood strength and stiffness were strongly correlated with wood density (0.86 and 1.04 respectively) and microfibril angle (-0.79 and -0.62 respectively). Acoustic velocity was strongly correlated with wood stiffness (0.81) and microfibril angle (- 0.83). The ability to select trees for wood stiffness with the use of acoustics along with the moderate inheritance of this trait should enable improvements in the wood quality of Sitka spruce. Despite the unfavourable correlation between growth rate and some key wood quality traits associated with timber strength, selection of certain families would enable modest gains to be made in both growth rate and wood quality.

Magistro darbe tiriama galimybė veisti plantacinius želdinius iš svetimžemių eglių rūšių greitam medienos išauginimui Lietuvoje. Darbo tikslas – įvertinti sitkinės eglės (Picea sitchensis), baltosios eglės var. alberta (Picea gauca var. albertiana), raudonosios eglės (Picea rubens), ajaninės eglės (Picea jezoensis), tarprūšinių hibridų – paprastoji eglė x kanadinė eglė (Picea abies x Picea glauca), paprastoji eglė x baltoji eglė (Picea abies x Picea glauca var. albertiana) genotipų tinkamumą sutrumpintos rotacijos plantaciniams želdiniams. Darbo objektas – Rokų Kelmyno bandomieji želdiniai. Darbo metodai ir techninės priemonės – tyrimo metu buvo įvertinti medžių kokybiniai ir kiekybiniai požymiai bandomuosiuose želdiniuose naudojant tokius prietaisus ir metodus: aukštis - aukštimačiu, skersmuo – žerglėmis, kokybiniai požymiai buvo įvertinti pagal vizualaus medžių kokybinių požymių įvertinimo metodiką. Taip pat buvo atlikta šių duomenų statistinė analizė. Naudoti tokie metodai: aprašomosios statistikos rodiklių palyginimas ir tiesinė koreliacinė analizė. Darbo rezultatai. Picea sitchensis ir abu tarprūšiniai hibridai pasižymi didesniu skersmeniu ir aukščiu, taip pat didesniu tūriu, nei vietinė paprastoji eglė. 33 metų amžiuje Picea sitchensis produkuoja 540 m3/ha medienos, kas rodo jos tinkamumą trumpos apyvartos želdiniams. Picea glauda var. albertiana, Picea jezoensis, ir Picea rubens produktyvumas yra mažesnis nei Picea abies. Didžiausiu tiesių ir vienastiebių... [toliau žr. visą tekstą] / This master thesis analyses possibility to cultivate exotic spruce plantations for shorten rotation forestry in Lithuania. Objective of the study was to find out suitability of Picea sitchensis, P. gauca var. albertiana, P. rubens, P. jezoensis, P. abies x P. glauca, P. abies x P. glauca (var. albertiana) for shorten rotation plantations. Object – Roku Kelmyno experimental forest area. Methods – such qualitative and quantitative tree parameters as height, diameter were assessed using clinometer and callipers. Qualitative parameters were assessed using visual tree qualitative parameters assessment methodics. All data was statistically analyzed. Methods used: comparison of descriptive statistics parameters and linear correlation analyzes. The results – Picea sitchensis and both interspecific hybrids have bigger diameter, height and volume parameters than local Norway spruce. Picea sitchensis produce 540 m3/ha of timber in 33 years, it shows suitability for shorten rotation plantations. Productivity of Picea glauda var. albertiana, Picea jezoensis, and Picea rubens is poor compared to Picea abies. Biggest percentage of straight and single-stemed trees were noticed in sitka spruce and both hybrids stands. Yezo spruce had the smallest percentage (62%) of healthy trees. Whereas the other tree species had percentage of healthy trees between 80 and 95. Branches positioned by blunt angle according the steam dominated in all stands and percentage of such trees was from 88 to 100. P... [to full text]