scholarly journals Effects of Aspen and Spruce Density on Size and Number of Lower Branches 20 Years after Thinning of Two Boreal Mixedwood Stands

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 211
Author(s):  
Philip G. Comeau
Keyword(s):  
Significant Interaction ◽  
Wood Quality ◽  
Branch Diameter ◽  
Breast Height ◽  
Crown Width ◽  
Interaction Term ◽  
Study Sites ◽  
Branch Size ◽  
Significant Interaction Term ◽  
Number Of Branches

This study examined branch diameter, number of whorls, and number of branches in the lower 2 m of the stems of white spruce growing in pure stands and in mixture with a range of densities of trembling aspen. Data were collected from two study sites located north of Big River Saskatchewan, which were regenerated following clearcutting in 1992 and thinned in 1996 to five aspen densities and two spruce densities. Results show significant decreases in spruce diameter at breast height (DBH), height, live crown ratio, maximum branch diameter in the lower 2 m, average branch diameter in the whorl closest to 1 m, and increases in tree slenderness with increases in aspen density. Increasing spruce density reduced the number of live branches and number of live branch whorls in the lower 2 m. Maximum branch diameter in the whorl closest to 1 m was influenced by both aspen and spruce density, with a significant interaction term resulting from effects of intraspecific competition being evident for aspen densities of 1500 stems ha−1 or lower. DBH and slenderness explained more than 49% of the variation in spruce crown width, maximum branch diameter in the lower 2 m, maximum live branch diameter in the whorl closest to 1 m, and average live branch diameter in the whorl closest to 1 m. DBH explained more variation in crown width and branch diameter than slenderness. This study demonstrates that growing spruce in mixture with aspen can lead to reductions in branch size and that early thinning to low aspen densities could lead to increases in size of knots and associated reductions in wood quality, particularly when spruce densities are low.

scholarly journals Pengaruh Dosis Pupuk KCl dan Persentase Defoliasi terhadap Pertumbuhan dan Hasil Tanaman Tin (Ficus carica L.)

2020 ◽  
Vol 5 (2) ◽  
pp. 81-90
Author(s):  
Raudatul Jannah ◽  
Nurhayati Nurhayati ◽  
Cut Nur Ichsan
Keyword(s):  
Significant Interaction ◽  
Leaf Length ◽  
Ficus Carica ◽  
Growth And Yield ◽  
Leaf Width ◽  
Harvest Time ◽  
Branch Diameter ◽  
Number Of Leaves ◽  
Banda Aceh ◽  
Number Of Branches

Abstrak. Penelitian ini bertujuan untuk mengetahui pengaruh dosis pupuk KCl dan persentase defoliasi yang tepat serta interaksi antara kedua faktor tersebut terhadap pertumbuhan dan hasil tanaman  tin. Penelitian ini dilaksanakan di Rumah Kasa komplek Fakultas Pertanian, Universitas Syiah Kuala, Darussalam, Banda Aceh. Pelaksanaan penelitian dimulai dari bulan Juli sampai September 2019. Rancangan penelitian yang digunakan adalah Rancangan Petak Terpisah pola RAK faktorial 3 x 2 dengan 3 ulangan. Faktor yang diteliti yaitu pengaruh dosis pupuk KCl yang terdiri atas 3 taraf (0 g-1tan-1thn, 700 g-1tan-1thn, 800 g-1tan-1thn) dan persentase defoliasi yang terdiri atas 2 taraf (30% dan 60%). Hasil penelitian menunjukkan  bahwa dosis pupuk KCl berpengaruh  sangat nyata terhadap pertambahan jumlah  daun 2, 4, 6, 8 dan 10 MSP (minggu setelah  perlakuan) ,  pertambahan panjang daun 2 dan 10 MSP,  pertambahan lebar daun 2 dan 10 MSP, pertambahan jumlah cabang 2 dan 10 MSP, pertambahan diameter cabang 2 dan 10 MSP, pertambahan jumlah buah 2, 4, 6, 8 dan 10 MSP dan jumlah buah total serta berat buah 2, 4, 6, 8 dan 10 MSP dan berat buah total. Pertumbuhan dan hasil tanaman tin yang terbaik dijumpai pada dosis pupuk KCl 800 g-1tan-1thn dengan pertambahan hasil rata-rata 15,4 t. ha-1untuk2 bulan masa panen. Hasil penelitian menunjukkan bahwa persentase defoliasi berpengaruh sangat nyata terhadap pertambahan jumlah daun 2, 4, 6, 8 dan 10 MSP, pertambahan panjang daun 2 dan 10 MSP, pertambahan lebar daun 2 dan 10 MSP, pertambahan jumlah cabang 2 dan 10 MSP, pertambahan diameter cabang 2 dan 10 MSP, pertambahan jumlah buah 2 dan 4 MSP dan berat buah 10 MSP total, berpengaruh nyata terhadap jumlah buah 6, 8 dan 10 MSP dan jumlah buah total serta berat buah 2, 4, 6, 8 MSP. Pertumbuhan dan hasil tanaman tin terbaik dijumpai pada defoliasi daun 60% dengan pertambahan hasil rata-rata 12,6 t. ha-1untuk2 bulan masa panen. Terdapat interaksi yang sangat nyata antara dosis pupuk KCl dan persentase defoliasi terhadap pertambahan jumlah daun 4, 6 dan 8 MSP, pertambahan panjang daun 2 dan 10 MSP, pertambahan lebar daun 2, jumlah cabang 2 dan 10 MSP, pertambahan diameter cabang 2 dan 10 MSP dan jumlah buah 2 MSP dan berpengaruh nyata terhadap pertambahan jumlah daun 2 MSP. Pertumbuhan dan hasil tanaman tin terbaik dijumpai pada perlakuan dosis pupuk KCl 800 g-1tan-1thn dengan defoliasi 60%.The Effect of Potassium Chloride (KCl) Fertilizer Doses and DefoliationPercentage on the Growth and the Yield of Fig (Ficus carica L.)Abstract. This research aims to examine the effect of potassium chloride (KCl) fertilizer doses and defoliation percentage on the growth and the production of Fig (Ficus carica L.) and the interaction between these factors on the growth and production of fig plants. This research was conducted at the Screen House of Faculty of Agriculture, Syiah Kuala University, Darussalam, Banda Aceh. The research was carried out from July to September 2019. The research used split-plot design of 3 x 2 factorial RCBD with 3 replications. KCl fertilizer doses consisting of 3 levels (0 g tree-1 yr-1,700 g tree-1yr-1, 800 g tree-1 yr-1) and defoliation percentage consisting of 2 levels (30 % and 60 %). The result shows that KCl fertilizer dose has a very significant effect on increasing the number of leaves to 2, 4, 6, 8 and 10 WAT (week after treatment), increasing leaf length at 2 and 10 WAT, leaf width at 2 and 10 WAT, the number of branches at 2 and 10 MSP, branch diameter at 2 and 10 WAT, the number of fruits at 2, 4, 6, 8 and 10 WAT, and fruit weight at 2, 4, 6, 8 and 10 WAT. The best growth and yield of fig plants were found at a dose of KCl 800 g tree-1 yr-1with 15,4 t. ha-1 increasing fot two mounths harvest time. Percentage of defoliation has a very significant effect on increasing the number of leaves at 2, 4, 6, 8 and 10 WAT, the number of branches at 2 and 10 MSP, the number of fruits at 6 WAT, significantly affected in increasing the number of leaves at 2 and 10 WAT, leaf width at 2 WAT, the number of branches at 2 MSP, branch diameter at 2 and 10 WAT, the number of fruits at 4, 8 and 10 WAT. The best growth and yield of fig plants were found at 60% defoliation treatment1with 12,6 t. ha-1 increasing fot two mounths harvest time. Thus, there was a very significant interaction between the dose of KCl fertilizer and the percentage of defoliation on the increasing the number of leaves at 4, 6 and 8 WAT), leaf length at 2 and 10 WAT, leaf width at 2 WAT, the number of branches at 2 and 10 MSP, branch diameter at 2 and 10 WAT, the number of fruits at 2 WAT and significant interaction on the number of leaves to 2 WAT. The best growth and  yield of fig plants were found in a combination of a dose of 800 g tree-1 yr-1 of KCl fertilizer with 60% of defoliation.

Simple Question, Not So Simple Answer: Interpreting Interaction Terms in Moderated Multiple Regression

1994 ◽  
Vol 20 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Arthur G. Bedeian ◽  
Kevin W. Mossholder
Keyword(s):  
Multiple Regression ◽  
Significant Interaction ◽  
A Priori ◽  
Moderated Multiple Regression ◽  
Statistical Comparison ◽  
Interaction Terms ◽  
Simple Question ◽  
Interaction Term ◽  
Significant Interaction Term

The appropriate interpretation of interaction terms in studies employing moderated multiple regression ( MMR) analysis is considered. It is argued that given a theory-based, a priori hypothesis, an MMR analysis is analogous to a planned statistical comparison and, thus, a significant overall F value is not a prerequisite for interpreting a significant interaction term.

scholarly journals Cardiorespiratory Fitness and Muscular Strength Moderates the Relationship between FNDC5 Polymorphism and Adiposity in Children and Adolescents

2021 ◽  
Vol 18 (18) ◽  
pp. 9797
Author(s):  
Pâmela Ferreira Todendi ◽  
Caroline Brand ◽  
João Francisco de Castro Silveira ◽  
Ryan Donald Burns ◽  
J. Alfredo Martínez ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Cardiorespiratory Fitness ◽  
Skin Color ◽  
Significant Interaction ◽  
Muscular Strength ◽  
School Type ◽  
Interaction Term ◽  
The Relationship ◽  
Significant Interaction Term

The human locus FNDC5 rs16835198 contributes positively to anthropometric phenotypes in children and adolescents. However, the role of specific components of physical fitness in this relationship is not known. The present study aimed to verify the moderator role of cardiorespiratory fitness (CRF) and muscular strength in the relationship between rs16835198 polymorphism FNDC5 and adiposity in children and adolescents. This cross-sectional study was carried out by genotyping the rs16835198 FNDC5 polymorphism in 1701 children and adolescents (mean age 11.73 ± 2.75 years). Obesity was assessed using waist circumference and body mass index (BMI) z-scores. To evaluate CRF and muscular strength, the 6 min run/walk test and lower limb strength (LLS) were used. Linear regression models were applied, and all analyses were adjusted for age, sex, skin color, living area, and school type. A significant interaction term for CRF (p = 0.038) and LLS (p = 0.040) × rs16835198 FNDC5 with WC was identified. Regarding BMI, a significant interaction term for CRF (p = 0.007) and LLS (p = 0.044) × rs16835198 FNDC5 was observed. Moreover, medium and high CRF and LLS levels protected against higher WC and BMI. In conclusion, adiposity levels of children and adolescents with a genetic predisposition to obesity might be modified by improving CRF and muscular strength.

Wachstum und Wertleistung der Douglasie in Abhängigkeit von der Standraumgestaltung

2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  
Keyword(s):  
Wood Quality ◽  
Volume Growth ◽  
Static Stability ◽  
Douglas Fir ◽  
Breast Height ◽  
Monetary Analysis ◽  
Starting Conditions ◽  
Tree Number ◽  
Clear Differentiation ◽  
Further Development

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.

scholarly journals 312 Female sex independently predicts adjuvant immunotherapeutic benefit from CTLA4 immune checkpoint inhibition

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A339-A339
Author(s):  
Ahmad Tarhini ◽  
Ni Kang ◽  
Sandra Lee ◽  
F Stephen Hodi ◽  
Gary Cohen ◽  
...  
Keyword(s):  
Overall Survival ◽  
Treatment Efficacy ◽  
Significant Interaction ◽  
Cox Regression ◽  
Performance Status ◽  
Phase Iii ◽  
High Dose ◽  
List Type ◽  
Female Sex ◽  
Interaction Term

BackgroundSex differences in tumor immunity and response to immunotherapy were shown in murine models and descriptive analyses from recent clinical trials. Female sex hormones have been implicated in melanoma development and response to systemic therapy. We hypothesized a gender difference in response to adjuvant immunotherapy with ipilimumab (3 or 10 mg/kg; ipi3 or ipi10) versus high dose IFNα (HDI) as tested in the E1609 trial.MethodsE1609 demonstrated significant overall survival (OS) benefit with ipi3 versus HDI.1 We investigated treatment efficacy between ipi and HDI in the subgroups by sex (female, male), age (< 55 or ≥55), stage at study entry (IIIB, IIIC, M1a/1b), ECOG performance status (PS 0, 1), ulceration (yes, no), primary tumor (known, unknown), number of lymph nodes involved (0, 1, 2–3, 4+). Forest plots were created to compare OS and RFS with ipi3 vs. HDI and ipi10 vs. HDI using the concurrently randomized ITT populations. For the estimated HRs, 95% confidence intervals were created for all subgroups.ResultsThe subgroups of female, stage IIIC, PS=1, ulcerated, in-transit without lymph node involvement demonstrated significant improvement in overall survival (OS) and/or relapse free survival (RFS) with ipi3 versus HDI as summarized in table 1. Female sex was significant for both OS and RFS and was further explored. In investigating RFS with ipi3 versus HDI, a multivariate Cox regression model including sex, treatment and interaction term of sex*treatment, indicated a significant interaction between sex and treatment (P = 0.026). Including sex, PS (0 vs. 1), age (<55 vs. 55+), ulceration (yes vs. no), stage (IIIB, IIIC, M1a, M1b), treatment and interaction term of sex*treatment, indicated a significant interaction between sex and treatment (P = 0.024). While similar trends were seen, no significant interactions between sex and treatment effect were found in the OS multivariate analysis or in the comparison of ipi10 versus HDI. When exploring age, in the univariate analyses in the ipi3 versus HDI comparison older women appeared to drive most of the difference (age ≥55: OS, P=0.02 and RFS, P=0.08; differences non-significant for women <55). Table 1.Abstract 312 Table 1Treatment efficacy between ipi3 and HDI by subgroupConclusionsFemale sex was independently associated with RFS adjuvant immunotherapeutic benefit from ipi3, supporting a potentially important role for female related factors in the immune response against melanoma, and these warrant further investigation.Trial RegistrationNCT01274338Ethics ApprovalThe study protocol was approved by the institutional review board (IRB) of each participating institution and conducted in accordance with Good Clinical Practice guidelines as defined by the International Conference on Harmonisation. This study was monitored by the ECOG-ACRIN DataSafety Monitoring Committee and the NCI.ConsentAll patients provided IRB-approved written informed consent.ReferenceTarhini AA, Lee SJ, Hodi FS, Rao UNM, Cohen GI, Hamid O, Hutchins LF, Sosman JA, Kluger HM, Eroglu Z, Koon HB, Lawrence DP, Kendra KL, Minor DR, Lee CB, Albertini MR, Flaherty LE, Petrella TM, Streicher H, Sondak VK, Kirkwood JM. Phase III Study of Adjuvant Ipilimumab (3 or 10 mg/kg) Versus High-Dose Interferon Alfa-2b for Resected High-Risk Melanoma: North American Intergroup E1609. J Clin Oncol. 2020 Feb 20;38(6):567–575. PMID: 31880964.

scholarly journals Development of stem cracks in young hybrid aspen plantations

2016 ◽  
Vol 65 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Silva Šēnhofa ◽  
Mārtiņš Zeps ◽  
Arnis Gailis ◽  
Rolands Kāpostiņš ◽  
Āris Jansons
Keyword(s):  
Crack Width ◽  
Crack Formation ◽  
Fungal Infections ◽  
Wood Quality ◽  
Tree Age ◽  
Hybrid Aspen ◽  
Breast Height ◽  
Grade Scale ◽  
Clear Relation ◽  
Selection Of

Abstract Cracks expose wood to fungal infections that significantly affects wood quality, while rapid wound occlusion decreases probability of infections. Assessment of scars was done at four grade scale in three adjacent hybrid aspen trials at the age of 8-10 years in central part of Latvia three years after bark crack occurrence. Occluded wounds were found for 95% of damaged trees, regardless of tree age. Among trees that had cracks wider than 1 cm, 42% had uniformly healed bark, but 7% still had open wounds. Wound development was significantly affected by crack width and length (both p < 0.001), but had no clear relation with tree DBH (diameter at breast height) and relative DBH increment (both p > 0.05). At clonal mean level, scar grade was significantly affected by grade of crack three years earlier and clone (both p < 0.001), but mean DBH of clone had no relation (p > 0.05) to proportion of trees evaluated by any of the scar grades. The results suggest that three years after the bark crack formation most of them had successfully occluded and selection of clones with better diameter growth has no influence on development of cracks.

scholarly journals VARIAÇÃO LONGITUDINAL E EFEITO DO ESPAÇAMENTO NA MASSA ESPECÍFICA BÁSICA DA MADEIRA DE Mimosa scabrella E Ateleia glazioveana

FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 327 ◽  
Author(s):  
Elder Eloy ◽  
Braulio Otomar Caron ◽  
Rômulo Trevisan ◽  
Denise Schmidt ◽  
Magda Lea Bolzan Zanon ◽  
...  
Keyword(s):  
Block Design ◽  
Wood Quality ◽  
Basic Density ◽  
Technological Characteristic ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Living Space ◽  
Randomized Complete Block Design ◽  
Axial Variation ◽  
Set Up

 Este trabalho teve como objetivo avaliar a variação longitudinal e o efeito do espaçamento de plantio na massa específica básica das árvores de Mimosa scabrella Benth e Ateleia glazioveana Baill, aos 36 meses de idade. Analisou-se um experimento instalado em delineamento de blocos completos casualizados, com três repetições. Os tratamentos foram definidos em função dos espaçamentos (2,0x1,0 m, 2,0x1,5 m, 3,0x1,0 m e 3,0x1,5 m). Foram avaliadas 72 árvores, sendo essas medidas e cubadas pelo método de Smalian. Em seguida, foram retirados discos nas posições do tronco: 0,10 m (base), 1,30 m do solo (DAP – Diâmetro a Altura do Peito), 25%, 50% e 75% da altura total da árvore, para determinação da massa específica básica. A massa específica básica em árvores de Mimosa scabrella apresentou um decréscimo até a região do DAP, seguido de acréscimo, sem tendência de estabilização com a altura. A Ateleia glazioveana apresentou uma tendência de decréscimo no sentido base-topo das árvores. Os espaçamentos influenciaram a variação da massa específica básica em árvores de Mimosa scabrella e Ateleia glazioveana, não sendo verificada uma variação sistemática positiva ou negativa em relação ao espaço vital proporcionado.Palavras-chave:  Variação axial; característica tecnológica da madeira; qualidade da madeira; espaçamento de plantio. AbstractLongitudinal variation and effect of spacing on basic density wood of Mimosa scabrella and Ateleia glazioveana. This study aimed to evaluate the variation in length and effect of spacing of the basic density of Mimosa scabrella Benth e Ateleia glazioveana Baill, trees with 36 months of age. We analyzed an experiment set up in randomized complete block design with three replications. The treatments were defined by the spacing (2.0x1.0 m, 2.0x1.5 m, 3.0x1.0 m, 3.0x1.5 m). 72 trees were evaluated, and these measures and scaled by the method of Smalian. Then, the disks were removed from the trunk positions: 0.10 m (base), 1.30 m (DAP - diameter at breast height), 25%, 50% and 75% of the total height of the tree, determining the basic density. The basic density in trees of Mimosa scabrella showed a decrease to the region of the DAP, followed by addition, without a tendency to stabilize with time. The Ateleia glazioveana showed a decreasing trend towards bottom-up tree. The spacing influenced the variation of basic density in trees of Mimosa scabrella e Ateleia glazioveana not been verified a systematic positive or negative trend in relation to the living space provided. Keywords: Axial variation; technological characteristic of wood; wood quality; planting space.

Breast-height relative density and radial growth in mature jack pine (Pinusbanksiana) for 38 years after thinning

1994 ◽  
Vol 24 (12) ◽  
pp. 2439-2447 ◽  
Author(s):  
R. James Barbour ◽  
David C.F. Fayle ◽  
Gilles Chauret ◽  
Jean Cook ◽  
Marianne B. Karsh ◽  
...  
Keyword(s):  
Relative Density ◽  
Wood Quality ◽  
Jack Pine ◽  
Pulp Yield ◽  
Northern Ontario ◽  
Short Supply ◽  
Average Spacing ◽  
Breast Height ◽  
Commercial Thinning ◽  
Rotation Age

Sawlogs are in short supply in northern Ontario, and thinning has been suggested as one way to improve the situation. The only rotation-age jack pine (Pinusbanksiana Lamb.) thinning trial in the region was examined to assess how commercial thinning influenced wood quality. This report covers an unreplicated trial of a 65-year chronology of pith to bark relative densities and growth rates based on X-ray densitometry of breast-height increment cores taken from trees on two thinned plots (average spacing 2.6 and 3.4 m) and an unthinned control (average spacing 1.7 m). The trees on the treatment plots responded to thinning by producing wood with significantly lower relative density than those on the control plot. This trend continued much longer than reported for other pines and could negatively affect pulp yield or mechanical properties of lumber. Enhanced earlywood growth caused a drop in the proportion of latewood that resulted in the decline in density. Thinning may have improved moisture availability during the early and middle season and encouraged earlywood growth. Density and growth rate differences became apparent soon after treatment. Early, rapid, and inexpensive estimates of the product potential of younger thinning trials are possible using the techniques demonstrated here.

Genetic parameters in diallel-crossed Scots pine favor heartwood formation breeding objectives

1998 ◽  
Vol 28 (6) ◽  
pp. 937-941 ◽  
Author(s):  
Anders Fries ◽  
Tore Ericsson
Keyword(s):  
Genetic Correlation ◽  
Scots Pine ◽  
Heritability Estimate ◽  
Tree Height ◽  
Heartwood Formation ◽  
Environmental Correlations ◽  
Branch Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Crown Length

After 25 years, full-sibs of Scots pine (Pinus sylvestris L.) in a north Swedish progeny test showed an estimated heritability of 0.30 for heartwood diameter at 80 cm above ground. This was equal to the heritability estimate for tree height, although accompanied by a much larger additive genetic coefficient of variation (0.20 compared with 0.06). The heritability estimate for diameter at breast height was about half that for tree height. Strong and positive phenotypic and environmental correlations were assessed between heartwood and the following traits: diameter at breast height, tree height, and branch diameter. The genetic correlation was low and positive at 0.02 between heartwood and diameter at breast height in contrast with 0.27 between heartwood and tree height. The assessed genetic correlations between heartwood and branch diameter and between heartwood and crown length were very weak compared with the phenotypic and, particularly, environmental correlations. This indicates that the association between crown length and heartwood is significant with regard to environmental factors, no matter to what extent they are independently modified by genes. However, crown limit was the trait that showed the strongest genetic correlation with heartwood (0.49). Since no correlations with production traits were unfavorable, we conclude that including heartwood formation capacity in a breeding programmay be done without drawbacks and with good prospects for success.

scholarly journals Stem Characteristics on the Lower Log of 35-Year-Old Western Redcedar Grown at Several Spacings

1997 ◽  
Vol 12 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Jeffrey D. DeBell ◽  
Barbara L. Gartner
Keyword(s):  
Large Diameter ◽  
Stem Diameter ◽  
Stem Length ◽  
Thuja Plicata ◽  
Western Redcedar ◽  
Branch Diameter ◽  
University Of British Columbia ◽  
The University ◽  
Number Of Branches

Abstract Information on stem characteristics of western redcedar (Thuja plicata) grown in managed stands is quite limited. Stem characteristics are important because they influence the quality of logs and lumber produced. We measured branch diameter, number of branches, taper, and fluting severity on the first 5m log of stems grown at spacings of 1.8 to 4.6 m in a 35-yr-old spacing trial on the University of British Columbia Research Forest. Average branch diameter increased from 15 mm to 25 mm as tree spacing increased from 1.8 m to 4.6 m. Number of branches per unit of stem length was unaffected by spacing. Trees at wider spacings tended to be more tapered and have more butt swell than those at narrower spacings. At wider spacings, more trees showed fluting, and that fluting was more severe than at narrower spacings. However, most trees had no fluting or only mild fluting even at the 4.6 m spacing. Branch diameter, taper, and fluting were all related to stem diameter. Smaller diameter stems tended to have smaller branches, less taper, and were less likely to have severe fluting than large diameter stems. Branch diameter was larger at wider spacings even for trees of the same stem diameter. West. J. Appl. For. 12(1):9-14.

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