The effects of fertilization and thinning on wood quality of a 24-year-old Douglas-fir stand

1989 ◽  
Vol 19 (9) ◽  
pp. 1137-1145 ◽  
Author(s):  
L. A. Jozsa ◽  
H. Brix
Keyword(s):  
Wood Quality ◽  
Ring Width ◽  
Douglas Fir ◽  
Ring Density ◽  
Beneficial Effects ◽  
Reduced Ring ◽  
Increasing Trend ◽  
Poor Site ◽  
Intermediate Effect

This report describes the growth and wood density response of a coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand on a poor site to thinning and nitrogen fertilization. The treatment plots were established in 1971 and 1972 at about 24 years of age. The effects of fertilization and thinning were evaluated 12 and 13 years after the initial treatments of the 1972 and 1971 plots, respectively, and 3 years after refertilization of the 1972 plots in 1981. Ring-width and ring-density data were obtained from pith to bark for all trees and were derived from computerized X-ray densitometry. Fertilization reduced ring density at breast height and 25% stem height by an average of 16% for a 3- to 4-year period after treatment, but not thereafter. Reductions in ring density resulted from decreases in the density of early wood and latewood, as well as from decreases in the percent of latewood. Effects were only pronounced in the lower half of the stem. Thinning resulted in a slight ring-density gain in the lower bole and a reduction in the top. The combined treatments had an intermediate effect on ring density. Ring density showed an increasing trend from pith to bark at all heights, except at the 75% height, and a decrease with increasing height in the bole. Fertilization and thinning both increased diameter growth, and their beneficial effects were still evident 13 years after treatments.

Influences of spacing on radial growth and percentage latewood of Douglas-fir, western hemlock, and western redcedar

1980 ◽  
Vol 10 (2) ◽  
pp. 169-175 ◽  
Author(s):  
J. Harry G. Smith
Keyword(s):  
Wood Quality ◽  
Ring Width ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Western Redcedar ◽  
X Ray ◽  
Good Site ◽  
Binocular Microscope ◽  
Reduced Costs ◽  
Ray Methods

Growth in ring width and percentage latewood on a very good site is described for 21-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), 20-year-old western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western redcedar (Thujaplicata Donn) planted at five spacings (0.91 to 4.57 m). Cores extracted at breast height are used to show the effects of spacing through growth rate and crown development, and of age through number of rings from pith for the years 1965 to 1976. Percentages of latewood measured by binocular microscope are compared with results obtainable by X-ray methods for analysis of ring widths and densities. Influences of spacing on wood quality are discussed. It is concluded that wide initial spacings increase ring width and decrease percentage latewood significantly, but the reduced costs and increased sizes at wide spacings provide more than adequate compensation for the moderate reduction in wood quality.

The Effect of Industrial Emission on Wood Quality in Norway Spruce (Picea Abies)

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 399-404 ◽  
Author(s):  
J. A. Evertsen ◽  
M. P. Mac Siurtain ◽  
J. J. Gardiner
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Manufacturing Process ◽  
Wood Quality ◽  
Ring Width ◽  
Wood Properties ◽  
Industrial Emission ◽  
Preliminary Study

In this preliminary study, the influence of industrial emission on the wood quality of Norway spruce was evaluated. Intrinsie wood quality determining properties: ring width (RW), mean annual density, percentage annual 1atewood and the product of (RW × (maximumminimum density)) appear to be affected by the emissions of a fertiliser factory adjoining the stands studied. Fluctuations in the performance of these intrinsic wood properties coincide with the start of production by the factory and a change in the manufacturing process.

Wood Quality of Sugi (Cryptomeria Japonica) Grown at four initial Spacings

IAWA Journal ◽  
2005 ◽  
Vol 26 (3) ◽  
pp. 375-386 ◽  
Author(s):  
F. Ishiguri ◽  
S. Kasai ◽  
S. Yokota ◽  
K. Iizuka ◽  
N. Yoshizawa
Keyword(s):  
Cryptomeria Japonica ◽  
Wood Quality ◽  
Microfibril Angle ◽  
Basic Density ◽  
Ring Width ◽  
The Other ◽  
Modulus Of Rupture ◽  
Density Control ◽  
Initial Spacing

Wood quality is affected by silviculture, which includes factors such as stand density control and genetics. In the present study, the effects of initial spacing on the general wood quality and lumber quality of sugi wood (Cryptomeria japonica D. Don) were examined. Logs of 35-year-old sugi were cut from four stands with different initial spacing (A: 2.6 by 2.6 m, 1,500 trees/ha; B: 1.8 by 1.8 m, 3,000 trees/ha; C: 1.3 by 1.3 m, 6,000 trees/ha; D: 1.0 by 1.0 m, 10,000 trees/ha). Trees from stand A showed significantly larger values in annual ring width than trees from the other stands. However, there were no significant differences in the wood basic density, the length of latewood tracheids, and the microfibril angle of the S2 layer among stands. On the other hand, initial spacing affected the lumber quality. The average diameter of knots was significantly larger in stand A than in the other stands. In addition, the dynamic Young's modulus, the modulus of rupture, and the modulus of elasticity in static bending increased with the decrease in the initial spacing from 2.6 by 2.6 m to 1.3 by 1.3 m.

Impact of the foliar pathogen Swiss needle cast on wood quality of Douglas-fir

2005 ◽  
Vol 35 (2) ◽  
pp. 331-339 ◽  
Author(s):  
G R Johnson ◽  
Amy T Grotta ◽  
Barbara L Gartner ◽  
Geoff Downes
Keyword(s):  
Moisture Content ◽  
Wood Density ◽  
Wood Quality ◽  
Ring Width ◽  
Wood Properties ◽  
Douglas Fir ◽  
Needle Cast ◽  
Needle Retention ◽  
Foliar Pathogen ◽  
Swiss Needle Cast

Many stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near coastal areas of Oregon and Washington are heavily infected with the foliar pathogen causing Swiss needle cast (SNC) disease, and yet there is very little research on the resulting wood quality. Modulus of elasticity (MOE), modulus of rupture (MOR), microfibril angle (MFA), wood density, latewood proportion, and sapwood moisture content were examined in 20- to 28-year-old trees from 15 stands that were infected with varying intensities of SNC. SNC severity was quantified by measuring needle retention, the number of needle cohorts retained at three crown levels. Correlations between disease severity and wood properties were examined at both the stand and within-stand levels. Trees from heavily infected stands (needle retention <2 years) had higher MOE, wood density, and latewood proportion and lower sapwood moisture content than trees from healthier stands. Breast-height age (BHage) was also correlated with these properties, but age alone did not explain all of the increases. MFA was not associated with SNC severity. Within stands, needle retention was not associated with MOE or MOR. The increase in latewood proportion in diseased stands appears to be the driving factor behind their increase in stiffness (MOE). Ring width decreased with decreased needle retention, and the examined wood properties generally showed stronger correlations with ring width than with needle retention.

Ring Width, Density and Wood Anatomy of Douglas Fir with Different Crown Vitality

IAWA Journal ◽  
1991 ◽  
Vol 12 (4) ◽  
pp. 453-465 ◽  
Author(s):  
Ingrid de Kort ◽  
Veronique Loeffen ◽  
Pieter Baas
Keyword(s):  
Cell Wall ◽  
Wood Quality ◽  
Rapid Assessment ◽  
Ring Width ◽  
Density Variation ◽  
Douglas Fir ◽  
Growth Rings ◽  
Cross Sectional ◽  
Sectional Surface ◽  
The Impact

The correlations of density, cell wall percentage, number of cells per cross sectional surface area, latewood percentage and ring width are analysed within growth rings, among rings of different widths, and among six Douglas fir trees of different vitality classes. There is a consistent, positive correlation between density, cell wall percentage and latewood percentage. Correlations of ring width with latewood percentage and density vary from tree to tree. For practical purposes latewood percentage can be used to explain c. 60% of the density variation. This parameter is recommended for rapid assessment of the impact of crown vitality on wood quality.

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.

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