Response of Lignin Metabolism to Light Quality in Wheat Population

The low red/far-red (R/FR) light proportion at the base of the high-density wheat population leads to poor stem quality and increases lodging risk. We used Shannong 23 and Shannong 16 as the test materials. By setting three-light quality treatments: normal light (CK), red light (RL), and far-red light (FRL), we irradiated the base internodes of the stem with RL and FRL for 7h. Our results showed that RL irradiation enhanced stem quality, as revealed by increased breaking strength, stem diameter, wall thickness and, dry weight per unit length, and the total amount of lignin and related gene expression increased, at the same time. The composition of lignin subunits was related to the lodging resistance of wheat. The proportion of S+G subunits and H subunits played a key role in wheat lodging resistance. RL could increase the content of S subunits and G subunits and the proportion of S+G subunits, reduce the proportion of H subunits. We described here, to the best of our knowledge, the systematic study of the mechanism involved in the regulation of stem breaking strength by light quality, particularly the effect of light quality on lignin biosynthesis and its relationship with lodging resistance in wheat.

Genetic Variation and the Effect of Herbicide and Fertilization Treatments on Wood Quality Traits in Loblolly Pine

The effect of silvicultural treatments (herbicide, fertilization, herbicide + fertilization) and the interactions with genetic effects were investigated for wood quality traits in a 16-year-old loblolly pine (Pinus taeda L.) genetic test established in southwest Georgia, USA. Fertilizer and herbicide treatment combinations were applied multiple times to main plots containing twenty-five open-pollinated families as sub plots. Significant differences among treatments were found for all traits. Squared acoustic velocity, used as a surrogate for wood stiffness, was higher in herbicide-only plots compared with other treatments. Wood density was considerably lower in fertilization plots. A large proportion of variance observed for wood quality traits was explained by additive genetic effects, with individual-tree heritabilities ranging from 0.78 (ring 7–16 section wood density) to 0.28 (ring 2–6 section wood density). Corresponding family-mean heritability values were well over 0.86. Genotype-by-treatment interactions were nonsignificant for all traits, indicating no need to match families to silvicultural treatments. Wood quality traits had weak genetic correlations with growth and stem quality traits (stem slenderness, sweep, and branch angle) with a range of −0.33 to 0.43, suggesting that recurrent selection on growth or stem quality traits would not adversely affect wood quality in loblolly pine. Study Implications: Silvicultural treatments of herbicide, fertilization, and their combination had significant effects on wood stiffness and wood density in a 16-year-old loblolly pine genetics-by-silviculture trial. When fertilizer was applied, wood density decreased, but the impact on stiffness was minimal. The herbicide treatment increased wood stiffness. As expected, there were large genetic differences for wood quality traits and growth and stem quality traits. Genetics-by-silvicultural treatment interactions were not significant for wood quality traits; family rankings were quite stable across cultural regimes. Families that performed well under one silvicultural treatment performed well under all treatments.

Assessing reduction of cluster size to estimate wood volume in an Amazonian forest

ABSTRACT While the Brazilian National Forest Inventory (NFI) is in progress, there is a growing demand to understand the effect of cluster size on the accuracy and precision of forest-attribute estimation. We aimed to find the minimum cluster size (in area) to estimate merchantable volume (MV) with the same accuracy and precision as the estimates derived from the original cluster of 8,000 m2. We used data from an inventory carried out in a forest unit (Bom Futuro National Forest) in the southwestern Brazilian Amazon, where 22 clusters were distributed as a two-stage sampling design. Three products were evaluated: (i) MV of trees with a diameter at breast height (DBH) ≥ 20 cm (P1); (ii) MV of trees with DBH ≥ 50 cm (P2); and (iii) MV of commercial species with DBH ≥ 50 cm and stem quality ‘level 1’ or ‘level 2’ (P3). We assessed ten scenarios in which the cluster size was reduced from 8,000 m2 to 800 m2. The accuracy of P1, P2 and P3 was highly significantly lower for reductions < 2,400 m². The precision was more sensitive to variations in cluster size, especially for P2 and P3. Minimum cluster sizes were ≥ 2,400 m² to estimate P1, ≥ 4,800 m² to estimate P2, and ≥ 7,200 m² to estimate P3. We concluded that it is possible to reduce the cluster size without losing the accuracy and precision given by the original NFI cluster. A cluster of 2,400 m² provides estimates as accurate as the original cluster, regardless of the evaluated product.

Stem Quality of European Beech in Latvia and Its Effect on Tree and Stand Monetary Value

Beech is expected to expand its range into the territory of Latvia due to climate change, but we lack information on its stem and wood quality as a measure of its economic importance. We studied external stem quality traits in beech stands with age of 69 to 131 years. Nine trees were cut and sampled to determine internal wood quality and the proportion of peelable cylinder. Tree value was calculated according to buckling by dimensions and buckling accounting for stem and wood defects. Trees of the second generation (69 years) had a significantly lower incidence of frost cracks (22.0% vs. 36.2%), epicormic branches (50.5 % vs. 65.8%), and forks (15.8% vs. 23.5%) as compared to trees from the first generation (115–131 years). All sampled trees had discolouration in the height of the first log. The proportion of the peelable cylinder was positively linked to tree height and ranged from 12% at the stump level to 33.4% at the tree height of 30 m. All analysed phenotypic traits decreased stand monetary value: frost cracks by 6% to 8%, all external traits by 16% to 20%, all external and internal traits by 29% to 33%.

“Differences in stem form and bark anomalies of northern red oak trees in forest stands in Canada and Germany”

Northern red oak wood is valuable for a variety of applications not only in its natural distribution range in North America, but also in Europe. Timber quality and stem diameter largely determine timber prices and respective uses. Silvicultural management is key to influencing tree growth and stem quality. In Germany, crop tree thinning is currently the standard treatment, while in Canada the shelterwood system is common practice. The objective of this study was to compare stem characteristics related to stem quality of northern red oaks from Canada with those from Germany to determine effects of different silvicultural treatments on stem quality. We examined stem characteristics from a total of 150 dominant northern red oaks in Canadian and German forest stands using the terrestrial laser scanning approach. Northern red oak stems in Canada (shelterwood system) were significantly straighter, whereas German stems (crop tree thinning approach) were significantly smoother on the surface and rounder on the upper parts of the stems (height 4 – 8 m). The number of bark anomalies decreased with increasing tree competition, indicating that competition is the main driver influencing external stem form and the occurrence or persistence of bark anomalies.

Provenance and Family Variation in Biomass Potential of Loblolly Pine in the Piedmont of North Carolina

Considerable genetic differences in loblolly pine (Pinus taeda L.) exist for growth, stem form, and wood quality traits that influence biomass/biofuel production. By planting genetically superior trees with desirable biomass/biofuel traits, it is possible to substantially increase the amount of biomass and potential sawtimber trees produced from plantations. Ten of the fastest growing loblolly pine families from two provenances, Atlantic Coastal Plain and Piedmont, were tested for their biomass potential in North Carolina on a Piedmont site. At this northern Piedmont site at age six years, there were no provenance differences for biomass production or for trees with sawtimber potential. Variation in volume and sawtimber potential was significant at the family level. For biomass plantations, risks can be mitigated because of shorter rotation length, allowing for a higher-risk seed lot to capture greater gains in terms of volume. For a longer-rotation sawtimber stand, a more conservative family deployment strategy should be considered to maintain stem quality at the end of the rotation. Understanding the different seed source families and harvest regimes is essential to ensure profitable returns from pine plantations. Study Implications Landowners in the southeastern United States have more choices than ever before regarding the choice of genetic stock of loblolly pine seedlings they plant, and the family selection should reflect the stand management objectives with regard to growth, stem form, and wood quality traits. In a biomass/biofuel production regime, planting families from nonlocal seed sources for increased growth can potentially increase the amount of biomass and sawtimber produced from the plantation, although risks such as increased susceptibility to winter storm damage must be considered. For biomass plantations, with shorter rotation lengths, risks can be reduced allowing for a higher-risk genotype to capture the greater gains in volume. For a sawtimber stand, genotype selections should be more conservative to ensure stem quality at the end of the rotation. Understanding different genotypes and harvest regimes is essential to maximize profit from plantations.

Norway Spruce Stem Parameters in Sites with Different Stand Densities in Lithuanian Hemiboreal Forest

Background and Objectives: The study aimed to determine the changes of the main stem and branch parameters of Norway spruce (Picea abies (L.) H. Karst) trees under different stand densities. More specifically, the objective was to develop the models for the determination of branch diameter in 0–6 m log from root collar, taken as one of the parameters directly influencing the stem quality. The study continues a piece of research on stem and branch parameters’ responses to different stand density (SD) in the plantations of coniferous tree species in Lithuania. Materials and Methods: The following key parameters were measured in this study: total tree height, diameter at breast height, height to the lowest live branch, height to the lowest dead branch, and diameter of all branches in 0–6 m log. The linear regression models to predict branch diameter in 0–6 m log were developed based on stand density (SD), tree characteristics (tree diameter at breast height, DBH; and tree height, H) and other related stem and branch parameters. Results and Conclusions: Directly measured tree DBH, branch diameters and number of branches in 0–6 m log decreased significantly with the increasing SD. In the 0–6 m log, the branch diameter and the diameter of the thickest branch were identified as the main parameters related to stem quality. The best fitted models, developed including SD, tree DBH, branch diameter, and diameter of the thickest branch in 0–3 m log, can be proposed as a predictor for stem-wood quality for Norway spruce in hemiboreal forest zone.

Long-term performance of Norway spruce in two provenance trials in Latvia

Norway spruce is economically important tree species in the Baltic Sea region, covering large areas and being productive in pure plantations. The species is often regenerated with planting. It is important to choose not only productive, but also robust reproductive material with good adaptability, hardiness and quality traits. The use of appropriate transferred provenances can be an option to increase forest productivity at final-harvest moment. Thus, it is necessary to know long-term fitness of different seedlots. We examined two provenances trials in Western and Eastern Latvia at the age of 34 and 29 years, respectively. We assessed effect of provenance on growth performance, stem quality, and budburst time. In milder climate of Western Latvia, superior growth showed northward-transferred later flushing provenances from the Carpathian Mountains and Lithuania, resulting in by up to 32 % higher yield than the trial mean. No advantages were observed for early flushing Western Russian seedlots facing southward transfer. Latvian provenances showed variable performance regarding productivity and stem quality. In harsher climate of Eastern Latvia, selection of productive local seedlots seemed reasonable option due to relatively lower probability of trees with stem defects comparing to transferred material.