Late-rotation nitrogen fertilization of Douglas-fir: growth response and fibre properties

2017 ◽  
Vol 47 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Cosmin N. Filipescu ◽  
John A. (Tony) Trofymow ◽  
Ross S. Koppenaal
Keyword(s):  
Nitrogen Fertilization ◽  
Growth Response ◽  
Negative Impact ◽  
Management Practice ◽  
Wood Quality ◽  
Fibre Length ◽  
Douglas Fir ◽  
Stem Volume ◽  
Fibre Properties ◽  
The Impact

Late-rotation fertilization of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) 5 to 10 years before harvesting is a common management practice in British Columbia and the US Pacific Northwest. Despite widespread operational application, knowledge on the impact of late-rotation fertilization on forests, especially fibre properties, is lacking. In this study, we evaluate the growth response and fibre properties following nitrogen fertilization in a productive second-growth coastal Douglas-fir site at age 57 years. Destructive sampling of dominant and co-dominant trees in fertilized and control plots 5 years after fertilization indicated significant gain in stem volume (30%–40%) that was uniformly distributed along the stem. There were no discernible effects on wood quality at the log level in terms of resonance acoustic velocity. However, fibre properties within breast height tree rings indicated significant reductions of ring wood density (by 8%), earlywood density (17%), latewood percentage (10%), and modulus of elasticity (8%). Tracheid dimensions declined in earlywood (reduction of wall thickness by 15%), latewood (radial diameter by 8%), and fibre length (by 6%). Results indicate that late-rotation nitrogen fertilization of Douglas-fir may lead to a significant growth response with only minimal reduction of fibre properties. It is possible that the negative impact on fibre properties could become more significant for repeated applications or higher rates of nitrogen fertilization.

A method to map within-tree distribution of fibre properties using SilviScan-3 data

2009 ◽  
Vol 85 (3) ◽  
pp. 409-414 ◽  
Author(s):  
Maurice Defo ◽  
Andrew Goodison ◽  
Nelson Uy
Keyword(s):  
Wood Properties ◽  
Douglas Fir ◽  
Stem Volume ◽  
Preliminary Evaluation ◽  
Fibre Properties ◽  
Tree Distribution ◽  
Triangular Elements ◽  
Armillaria Root Disease ◽  
The Impact ◽  
Tree Distributions

This paper shows how SilviScan-3 data can be used to map the within-tree distributions of wood properties, and to compute relevant statistics useful for tree-to-tree comparisons. An algorithm named EvaluTreeMap was developed for this purpose, based on subdividing the stem into triangular elements. It was validated using a stem of conical shape with properties exhibiting conical symmetry. To illustrate some applications of the program, it was used for the preliminary evaluation of the impact of Armillaria root disease on the fibre coarseness of Douglas-fir trees. Key words: SilviScan-3, fibre properties, within-tree variations, EvaluTreeMap, meshing, mapping, stem volume, tree's mean properties and standard deviation, Armillaria ostoyae, fibre coarseness, Douglas-fir

scholarly journals Shifts in Foliage Biomass and Its Vertical Distribution in Response to Operational Nitrogen Fertilization of Douglas-Fir in Western Oregon

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 511 ◽  
Author(s):  
Jacob D. Putney ◽  
Douglas A. Maguire
Keyword(s):  
Vertical Distribution ◽  
Nitrogen Fertilization ◽  
N Fertilization ◽  
Douglas Fir ◽  
Tree Level ◽  
Stem Volume ◽  
Parameter Estimates ◽  
Growth Responses ◽  
Basal Diameter ◽  
Dormant Season

Nitrogen (N) fertilization is a commonly applied silvicultural treatment in intensively managed coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantations. Field trials were established in a randomized complete block design by Stimson Lumber Company (Gaston, Oregon), to test the economic viability of N fertilization on their ownership and to better understand Douglas-fir growth responses. The 23 stands comprising the trials were Douglas-fir dominated, had a total age of 16–24 years, had been precommercially thinned, and had a density of 386–1021 trees ha−1. Fertilizer was applied aerially at a rate of 224 kg N ha−1 as urea during the 2009–2010 dormant season. In the dormant season of 2016–2017, seven growing seasons following application, 40 trees were felled and measured with the objective of assessing crown attributes and aboveground allometrics. Branch-level foliage mass equations were developed from 267 subsampled branches and were applied to the 40 felled sample trees on which the basal diameter and height of all live branches were measured, allowing estimation of both the total amount of foliage and its vertical distribution. A right-truncated Weibull distribution was fitted to data, with the truncation point specified as the base of live tree crown. The resulting tree-level parameter estimates were modeled as functions of tree-level variables. Stand-level factors not explicitly measured were captured through the use of linear and nonlinear mixed-effects models with random stand effects. Fertilization resulted in more total crown foliage mass in the middle crown-third and caused a downward shift in the vertical distribution of foliage, with implications for feedback responses in crown development and photosynthetic capacity. Defining the morphological responses of Douglas-fir crowns to nitrogen fertilization provides a framework for studying influences on stand dynamics and should ultimately facilitate improved site-specific predictions of stem-volume growth.

scholarly journals Multidecadal Growth of Western White Pine and Interior Douglas-Fir Following Site Preparation

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 509
Author(s):  
Jonathan R. Cherico ◽  
Andrew S. Nelson ◽  
Teresa B. Jain ◽  
Russell T. Graham
Keyword(s):  
Growth Response ◽  
Site Preparation ◽  
Douglas Fir ◽  
Growth And Yield ◽  
Response To Treatment ◽  
Stem Volume ◽  
Pinus Monticola ◽  
White Pine ◽  
Western White Pine ◽  
Competition Control

Site preparation is used to favor seedling regeneration and establishment by enhancing growing conditions and increasing resource availability, yet few studies have compared different site preparation techniques on growth and yield of trees over multiple decades. We destructively sampled 34-year old trees of western white pine (Pinus monticola Douglas ex D. Don) and Interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco planted at two sites using a replicated experiment to test the effectiveness of different site preparation treatments: (1) no site preparation, (2) scalping, (3) bedding, and (4) bedding plus three years of competition control with herbicide. Growth and yield were compared among the treatments, and models of growth were developed for each species and treatment combination. The herbicide treatment was the only treatment that consistently improved growth and yield of both species resulting in 19%–30% gains in height, 43%–63% gains in diameter, and 31%–109% gains in stem volume by age 34. Height growth response to herbicide was sustained until age 14 for white pine and age 12 for Douglas-fir, while the diameter response was sustained until age 23 for white pine and 20 for Douglas-fir. The later peak in growth for white pine suggests a better response to treatment and that the species was able to maintain higher growth following crown closure. Both species exhibited a Type 2 growth response to herbicide, suggesting competition control resulted in sustained gains over time with associated age shifts of 8.5 and 9.7 years for white pine and 7.1 and 10.2 years for Douglas-fir, height and diameter, respectively. This compares to scalping and bedding which produced no detectable difference in growth compared to the control, and in some instances, reduced growth. In the Northern Rocky Mountains, moisture is most limiting. This is likely why trees showed the greatest response to competition control. Interestingly, this growth was sustained well beyond seedling establishment.

Effects of urea and ammonium nitrate fertilizer on growth of a young thinned and unthinned Douglas-fir stand

1984 ◽  
Vol 14 (6) ◽  
pp. 952-955 ◽  
Author(s):  
H. J. Barclay ◽  
H. Brix
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Source ◽  
Nitrogen Fertilizer ◽  
Nitrogen Fertilization ◽  
Tree Mortality ◽  
Height Growth ◽  
Douglas Fir ◽  
Stem Volume ◽  
Volume Response ◽  
Nitrate Fertilizer

The effects of two sources of nitrogen fertilizer applied at rates of 224 and 448 kg N/ha on growth of a thinned and unthinned 24-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand were studied. Ammonium nitrate yielded higher growth of diameter and volume than did urea over a 9-year period, particularly with thinning. Height growth was not affected by nitrogen source. The efficiency of nitrogen fertilization in terms of stem volume response per kilogram of nitrogen applied was greatest with ammonium nitrate in thinned plots. Tree mortality increased substantially with level of fertilization for both sources, and decreased markedly with thinning.

Peer abusive supervision and third-party employee creativity from a social exchange theory perspective

2021 ◽  
Vol 49 (5) ◽  
pp. 1-12
Author(s):  
Liang Tan ◽  
Zhuang Ma ◽  
Jun Huang ◽  
Gengxuan Guo
Keyword(s):  
Social Exchange ◽  
Organizational Support ◽  
Social Exchange Theory ◽  
Negative Impact ◽  
Management Practice ◽  
Abusive Supervision ◽  
Exchange Theory ◽  
Third Party ◽  
Employee Creativity ◽  
The Impact

We used social exchange theory to construct a theoretical framework of peer abusive supervision, third-party perception of organizational support, third-party employee creativity, and third-party perception of supervisory organizational embodiment. We then empirically tested the theoretical model with 367 supervisor–employee paired dyads from five large real estate companies in China. The results show that peer abusive supervision had a negative impact on third-party employee creativity, and third-party perception of organizational support played a mediating role in this relationship. Further, third-party perception of supervisory organizational embodiment positively moderated the impact of peer abusive supervision on third-party perception of organizational support. Our results, which show the spillover effect and boundary conditions of abusive supervision on third-party employee creativity, are significant for the enhancement of employee creativity in corporate management practice.

scholarly journals Foliar Sulfate-Sulfur as a Nutrient Diagnostic Tool for Interior Douglas-Fir

2011 ◽  
Vol 26 (3) ◽  
pp. 147-150 ◽  
Author(s):  
Heidi J. Schmalz ◽  
Mark D. Coleman
Keyword(s):  
Diagnostic Tool ◽  
Nitrogen Fertilization ◽  
Growth Response ◽  
Rocky Mountain ◽  
Douglas Fir ◽  
Diagnostic Tools ◽  
Sulfate Sulfur ◽  
Archived Samples ◽  
Northern Idaho ◽  
The Relationship

Abstract Foliar diagnostic tools have been used with varying success to identify limiting nutrients in Douglas-fir (Pseudotsuga menziesii [Mirab.] Franco var. glauca [Beissn.] Franco). The mechanisms of sulfur and nitrogen metabolism in plants enable the measurement of nutrient fractions that may yield more informative results. Measurements of sulfate-sulfur in conifer foliage have shown potential as a diagnostic tool for predicting tree response to nitrogen fertilization. Using archived samples and data from previously established fertilizer trials in northern Idaho, we tested the relationship between foliar sulfate-sulfur concentrations in unfertilized trees and 2-year growth response to nitrogen fertilization in Rocky Mountain Douglas-fir (P. menziesii [Mirab.] Franco var. glauca [Beissn.] Franco). Sulfate-sulfur concentrations explained 42% of the variability in growth response, compared with 17% for the total nitrogen to sulfur ratio. Sulfate-sulfur concentrations were variable within sites, presenting a challenge to the feasibility of sampling. Our results suggest that further controlled research would aid in development of sulfate-sulfur as a foliar diagnostic tool.

Effect of Armillaria root disease on quality and value of green Douglas-fir lumber

2010 ◽  
Vol 86 (2) ◽  
pp. 263-266 ◽  
Author(s):  
M G Cruickshank
Keyword(s):  
Tree Species ◽  
Wood Quality ◽  
Douglas Fir ◽  
Root Disease ◽  
Tree Level ◽  
Stem Taper ◽  
Negative Effect ◽  
Key Words Disease ◽  
Armillaria Root Disease ◽  
The Impact

For a few tree species, scattered accounts of impact caused by root disease exist in the literature mainly at the tree level. No product quality impacts have ever been measured or properly costed. To provide some information on value impacts, green rough-sawn Douglas-fir lumber was cut from trees with and without Armillaria root disease. This produced 80 boards from six trees in two planted stands. Fewer boards came from living diseased trees compared to healthy trees of similar diameter (1.3 m) at both sites, suggesting that disease may affect stem taper or form. Lumber from diseased trees was affected most often by warp and for healthy trees by knots, but warp affected value the most. Disease appears to have at best no effect, and at worst, a negative effect on lumber value but is not likely to increase value. This is the first report of the impact of a root disease on lumber quality and value, but further work would be required to properly assess this. Key words: disease, Armillaria root disease, conifer, Douglas-fir, wood quality, lumber warping, lumber value, lumber grading

Four-year Basal Area Growth Response of a 25-year-old Douglas-fir Stand to Thinning and Urea Fertilization

1974 ◽  
Vol 4 (4) ◽  
pp. 568-571 ◽  
Author(s):  
Y. Jim Lee
Keyword(s):  
Nitrogen Fertilization ◽  
Growth Response ◽  
Basal Area ◽  
Douglas Fir ◽  
Site Quality ◽  
Growing Period ◽  
Basal Area Growth ◽  
Area Growth ◽  
Four Levels ◽  
Urea Fertilization

Four-year growth response to nitrogen fertilization and thinning is reported for an experiment established in a 25-year-old Douglas-fir stand of medium site quality. Four levels of nitrogen (0, 112, 224, and 336 kg N/ha), in the form of urea, were tested at two thinning levels in a randomized 4 × 2 × 2 factorial design replicated in 2 Blocks. Fertilizer was applied in spring or fall. Basal area growth per hectare in the thinned stand significantly surpassed that of the unthinned stand in the fourth growing period. Increased rate of nitrogen fertilization resulted in increased growth 1 year after fertilization. Urea applied in the fall resulted in greater growth response than that applied in the spring for the first growing period and over a 4-year period. Increased rate of fertilization increased mortality significantly in the fourth growing period, but had no prior effect. Thinning decreased mortality in all four growing periods.

Determination of relative economic weights for multitrait selection in coastal Douglas-fir

1998 ◽  
Vol 28 (8) ◽  
pp. 1164-1170 ◽  
Author(s):  
Carol A Aubry ◽  
W T Adams ◽  
Thomas D Fahey
Keyword(s):  
Wood Density ◽  
Wood Quality ◽  
Tree Height ◽  
Douglas Fir ◽  
Stem Volume ◽  
Branch Diameter ◽  
Economic Weights ◽  
Selection Indices ◽  
Multitrait Selection

Relationships between tree traits and tree value for lumber production were investigated. For the purposes of estimating relative economic weights for use in multitrait selection in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii), tree height, diameter at breast height, and branch diameter were measured on 164 trees (ages 36-66 years). Increment cores from a subsample (92) of these trees were assayed by X-ray densitometry to determine wood density. Bole volume was derived by summing the log volumes of all logs from each tree. Value of lumber recovered from each tree was determined in a separate mill study using both visual and machine stress rated (MSR) grading rules. Multiple linear regression was used to relate tree value to the growth and wood quality traits. Stem volume and branch diameter significantly influenced tree value under visual grading, with relative economic weights of 0.06dm3 and -5.22cm, respectively. Wood density significantly influenced tree value under MSR grading (relative economic weights: 0.06dm3, -6.69cm, and 0.06kg/mdm3, respectively), where lumber strength is measured more accurately. These regression coefficients can be used directly as economic weights in selection indices.

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