Wood density of western hemlock: effect of ring width

1994 ◽  
Vol 24 (3) ◽  
pp. 638-641 ◽  
Author(s):  
Jeffrey D. DeBell ◽  
John C. Tappeiner II ◽  
Robert L. Krahmer

Wood density of western hemlock (Tsugaheterophylla (Raf.) Sarg.) was determined by X-ray densitometry of strips from breast-height samples consisting of rings 20–24 from the pith. Ring parameters were averaged over the 5 years for each strip. Wood density was negatively correlated with radial growth rate. Average wood density dropped from 0.47 to 0.37 g/cm3 as average ring width increased from 2 to 8 mm. Wood density decreased at higher growth rates primarily because earlywood width increased while latewood width remained the same; as a result, percentage of latewood decreased. Earlywood density decreased slightly at higher growth rates, but latewood density was not significantly related to growth rate.

2004 ◽  
Vol 34 (12) ◽  
pp. 2433-2442 ◽  
Author(s):  
Dean S DeBell ◽  
Ryan Singleton ◽  
Barbara L Gartner ◽  
David D Marshall

Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. Growth and wood density traits of individual rings were measured via X-ray densitometry, and relationships of ring density and its components to age and growth rate were analyzed. Ring density was highest (0.49 g/cm3) near the pith, declined to 0.40 g/cm3 at age 10, remained stable to about age 25, and then increased gradually and remained between 0.43 and 0.44 g/cm3 from age 38 to 45 and beyond. A negative influence of rapid growth on whole ring density was greatest at young ages and diminished with time, becoming nonsignificant beyond age 30. Earlywood density, latewood density, and latewood proportion were all negatively related to ring width at young ages, but by age 21-25, latewood proportion was the only component of ring density that remained significantly diminished by increased growth rate. Residual differences in wood density (after age and growth rate were considered) did not appear to be related to either stand density or site class. Overall, young-growth hemlock trees are relatively uniform in wood density and likely to be more so if grown in intensively managed stands.


Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 199-203 ◽  
Author(s):  
M. P. Denne ◽  
C. M. Cahalan ◽  
D. P. Aebischer

Summary To assess the likely effects of silvicultural treatment on the wood quality of Nothofagus nervosa grown in the UK, and the possibilities of independent selection within seed origins for density and growth rate, ring width and wood density were analysed from pith to bark of 19 trees. Variations in vessel lumen size, vessel number mm−2, and total lumen area mm−2 were analysed in ten trees. Since density increased by only 0.005g cm−3 per mm increase in ring width, silvicultural practices such as initial spacing and thinning are not likely to have a substantial effect on the wood density of rauli. Similarly, variation in density with cambial age was significant but relatively minor in the 40- and 60-year old trees of the present sample, suggesting that the rotation length is unlikely to have any practical influence on the density of rauli. Considerable between-tree differences in density were found which did not correspond to differences in ring width, suggesting it should be feasible to select independently for density and growth rate. These differences in density were associated with differences in both vessel lumen size and vessel number mm−2


1980 ◽  
Vol 10 (2) ◽  
pp. 169-175 ◽  
Author(s):  
J. Harry G. Smith

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.


1998 ◽  
Vol 28 (4) ◽  
pp. 566-573 ◽  
Author(s):  
Limin Xiong ◽  
Naoki Okada ◽  
Takeshi Fujiwara ◽  
Sadaaki Ohta ◽  
Jonathan G Palmer

Seven different tree-ring parameters (total ring width, earlywood width, latewood width, maximum latewood density, minimum earlywood density, average earlywood density, and average latewood density) were obtained from pink pine (Halocarpus biformis Hook.) at one chronology site in New Zealand (NZ). The chronologies were analyzed individually and then compared with each other. The relationships between the different tree-ring parameters and climate data (NZ average and local climate data) are also presented. There were more significant climate response functions in the NZ national average climate series than that of local climate data series. Earlywood-related parameters (earlywood width, minimum density, and average earlywood density) were more sensitive to climate than those of latewood. Temperature during the NZ growth season (November-March) was found to be the most strongly related to tree growth. This study demonstrates that the use of both ring width and ring density data can increase the climate information obtained from ring widths and should lead to improved paleoclimate reconstructions in New Zealand.


1964 ◽  
Vol 42 (9) ◽  
pp. 1105-1118 ◽  
Author(s):  
M. W. Bannan

Tracheid size and rate of anticlinal divisions in the cambium were determined for lodgepole pine at several sites in western North America ranging in elevation from 3000 to 11,000 feet. The determinations were made at breast height in trees with boles 10–20 in. in diameter. The base rate of anticlinal division was low as compared with other conifers, the average being 0.8 divisions per cm of xylem increment when ring width exceeded 1.5 mm. The frequency of division increased as annual xylem production fell below 1 mm, and rose sharply with continued reduction in ring width under 0.3 mm. Maximum cell length was associated with a ring width of 1 mm, and the length decreased in both wide and narrow rings. The tangential width of the tracheids likewise lessened as ring width fell below 1 mm, the decline becoming accentuated with continued waning of growth to less than 0.3 mm. Cell diameter differed from the overall mean by more than 1 µ at only one site after allowance was made for dissimilarities in growth rate. Cells were shortest at the two highest sites. The newly formed partition in pseudotransverse division tended to be inclined in the same direction in neighboring cells, but the percentage of divisions deviating from the preferred orientation was higher than in other conifers. Reversals in direction of tilt occurred after varied intervals, these apparently being corrective in function.


1994 ◽  
Vol 24 (9) ◽  
pp. 1818-1823 ◽  
Author(s):  
S.Y. Zhang ◽  
G. Nepveu ◽  
R. Eyono Owoundi

Twenty-three trees of European oak (Quercuspetraea (Matt) Liebl. and Quercusrobur L.) were collected from northeastern France to study intratree and intertree variation in the following characteristics: (i) wood density as well as earlywood density and latewood density; (ii) various types of wood shrinkage; and (iii) ring width and its components. Both intratree variation and intertree variation in the three characteristics are significant, but intertree variation is generally smaller. However, the relative magnitude of intertree variation varies with characteristic: intertree variation accounts for about 40% of the total variation in radial, tangential, and volumetric wood shrinkage, 32.5% of the total variation in ring width, and 12.6% of the total variation in wood density. Furthermore, the intertree variation is closely and positively related to the intratree variation: among the three characteristics studied, both intertree variation and intratree variation were highest for ring width and its components, and lowest for wood density and its components. In addition, intratree variation increased remarkably with increasing tree age in these species. In general, intratree variation in wood density and wood shrinkage depends more on cambial age than on ring width. The present study, together with the information available so far, suggests that the quality of European oak wood could be significantly improved.


Author(s):  
Vladimír Gryc ◽  
Hanuš Vavrčík ◽  
Štěpán Gomola

Variability of ring width, wood density and swelling in beech from two different areas was analysed. The variability of each property was described along the stem radius. The analysis proved that the ring width decreased in direction from the pith to the outer part of the stem (cambium). Statistically significant difference of mean ring width between locality 1 and 2 was not found. Density and volumetric swelling of wood were statistically significantly different between localities. Results showed that the density and volumetric swelling decreased from pith to cambium. Statistically significant dependency between density and volumetric swelling of wood was proved. The average wood density of beech was 752 kg·m–3 at 12% moisture content.


1971 ◽  
Vol 1 (2) ◽  
pp. 90-98 ◽  
Author(s):  
M. L. Parker ◽  
W. E. S. Henoch

Two parameters of growth rings from Engelmann spruce (Piceaengelmannii Parry) near Peyto lake, Alberta were studied and compared. Indices of maximum density of the latewood were derived from densitometric plots of X-ray negatives. Indices of ring widths were also obtained from the same specimens. Latewood density proved to be more useful for dendrochronological studies than ring width. The indices of density were significantly correlated with mean maximum air temperature and monthly runoff during August for three rivers in the region near Peyto lake. Analysis of latewood density as well as ring width improves the potential for dating tree-ring materials, and for using them to estimate past environment, especially for trees, such as the Peyto lake Engelmann spruce, with rings that do not vary greatly in width from one year to the next.


1998 ◽  
Vol 28 (1) ◽  
pp. 56-68 ◽  
Author(s):  
Pierre Dutilleul ◽  
Marc Herman ◽  
Tomas Avella-Shaw

The main hypothesis tested in this paper is whether heavy thinnings affect the correlations among ring width, wood density, and mean tracheid length. Within-tree correlations were calculated between time series of yearly measurements. Among-tree correlations were computed (1) between averages over a growing period and (2) year by year. Correlations were analyzed on 20 fast-grown and 20 slow-grown Norway spruces (Picea abies (L.) Karst.) from an even-aged, plantation-grown stand near Rendeux, Belgian Ardennes. In the within-tree approach, fast-grown spruces showed a stronger negative correlation between ring width and fiber length. In among-tree approach 1, the widely held negative correlation between ring width and wood density vanished when the spruce growth rate was above 2.2 cm/year in circumference. Among-tree approach 2 demonstrated that the magnitude and sign of the correlations also depended on the year; a few years showed a significant correlation between ring width and wood density for the fast-grown Norway spruces, whereas the correlation was systematically negative and significant on many years for the slow-grown spruces. This study may explain part of the contradictory results reported in the literature concerning hypotheses similar to ours.


2008 ◽  
Vol 38 (6) ◽  
pp. 1470-1477 ◽  
Author(s):  
Maria João Gaspar ◽  
José Luís Louzada ◽  
Maria Emília Silva ◽  
Alexandre Aguiar ◽  
Maria Helena Almeida

This study contributes to the Pinus pinaster Ait. breeding programme, which is reaching the third generation by adding information on wood quality of 46 open-pollinated families from a progeny trial located in Leiria, Portugal, that originated from seed collected in a clonal seed orchard. A total of 552 seventeen-year-old trees were sampled at 2 m height. Trends were studied from the pith outward in variance components and narrow-sense heritability (h2) of wood density components and ring-width characteristics as well as genetic correlations between cambial ages. Mean ring density (RD), minimum density (MND), maximum density (MXD), earlywood density (EWD), latewood density (LWD), earlywood width, latewood width, ring width, latewood percentage, and heterogeneity index were determined using X-ray densitometry procedures. RD had higher genetic control (h2 = 0.63), and heritability values of earlywood components (h2MND = 0.54, h2EWD = 0.60) exceeded those of latewood components (h2MXD = 0.34, h2LWD = 0.26). Heritabilities increased with ring number from pith for almost all wood density components, and there were high age–age genetic correlations for wood density traits (rg > 0.98).


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