Effects of release from suppression on wood functional characteristics in young Douglas-fir and western hemlock

2006 ◽  
Vol 36 (8) ◽  
pp. 2038-2046 ◽  
Author(s):  
Heidi J Renninger ◽  
Barbara L Gartner ◽  
Frederick C Meinzer
Keyword(s):  
Moisture Content ◽  
Wood Density ◽  
Growth Ring ◽  
Specific Conductivity ◽  
Ring Width ◽  
Wood Properties ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Growth Ring Width

Little is known of wood properties in trees that were initially suppressed and subsequently released from suppression. The purpose of this study was to assess differences in growth ring width, specific conductivity (Ks), tracheid dimensions, moisture content, and wood density in suppressed Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees and trees released from suppression averaging 12–18 years of age. Growth ring width was 370% higher for Douglas-fir and 300% higher for western hemlock trees released from suppression, and Ks was 182% higher for Douglas-fir and 42% higher for western hemlock trees released from suppression. Earlywood width was approximately four times greater after release in both species, whereas the relative increase in latewood width was much greater in Douglas-fir. Tracheids were 25% wider and 11% longer in released Douglas-fir trees. In western hemlock, released trees had 19% wider tracheids that were approximately the same length as those in suppressed trees. Moisture content was 66% greater in released Douglas-fir and 41% greater in released western hemlock. Wood density decreased by 21% in Douglas-fir trees and by 11% in western hemlock trees released from suppression. However, wood density of released trees did not differ from average reported values, implying that wood from released trees may be suitable for many of its traditional applications.

scholarly journals Effects of live crown on vertical patterns of wood density and growth in Douglas-fir

2002 ◽  
Vol 32 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Barbara L Gartner ◽  
Eric M North ◽  
G R Johnson ◽  
Ryan Singleton
Keyword(s):  
Wood Density ◽  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Mature Wood ◽  
Node Number ◽  
Growth Ring Width ◽  
Residual Variation ◽  
Wide Range

It would be valuable economically to know what are the biological triggers for formation of mature wood (currently of high value) and (or) what maintains production of juvenile wood (currently of low value), to develop silvicultural regimes that control the relative production of the two types of wood. Foresters commonly assume the bole of softwoods produces juvenile wood within the crown and mature wood below. We tested that assumption by comparing growth ring areas and widths and wood density components of the outer three growth rings in disks sampled from different vertical positions of 34-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. The 18 trees were sampled from one site and had a wide range of heights to live crown. Most of the variance (63–93%) in wood characteristics (growth ring area: total, earlywood, latewood; growth ring width: total, earlywood, latewood; latewood proportion: by area, width; and ring density: total, earlywood, latewood) was due to within-tree differences (related to age of the disk). Stepwise regression analysis gave us equations to estimate wood characteristics, after which we analyzed the residuals with a linear model that included whether a disk was within or below the crown (defined as the lowest node on the stem with less than three live branches). After adjusting for tree and disk position, only 2–10% of the residual variation was associated with whether the disk was in or out of the live crown. There were no statistically significant differences at p = 0.05 between a given disk (by node number) in versus out of the crown for any of the factors studied. Moreover, the wood density characteristics were not statistically significant at p = 0.30. This research suggests that there was no effect of the crown position on the transition from juvenile to mature wood as judged by wood density. Therefore, we found no evidence to support the concept that tree spacing and live-branch pruning have a significant effect on the cambial age of transition from juvenile to mature wood in Douglas-fir trees of this age.

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.

Effects of defoliation on growth, biomass allocation, and wood properties of Betula pendula clones grown at different nutrient levels

2002 ◽  
Vol 32 (3) ◽  
pp. 498-508 ◽  
Author(s):  
Seija Anttonen ◽  
Riikka Piispanen ◽  
Jari Ovaska ◽  
Pia Mutikainen ◽  
Pekka Saranpää ◽  
...  
Keyword(s):  
Nutrient Availability ◽  
Recovery Time ◽  
Betula Pendula ◽  
Growth Ring ◽  
Ring Width ◽  
Wood Properties ◽  
Minor Role ◽  
Total Biomass ◽  
Nutrient Levels ◽  
Growth Ring Width

Three-year old Betula pendula Roth clones were grown at two nutrient levels in a field experiment to investigate the responses and recovery in growth and wood properties to a range of defoliation levels (0–100%). No general threshold value of defoliation level for negative effects in growth was found, since the sensitivity of saplings to defoliation varied according to plant traits studied. However, responses were related to defoliation intensity. Saplings compensated for 25% defoliation in terms of height growth and number of current branches and were able to tolerate 50% defoliation without effects on diameter growth 1 year after the defoliation. Nutrient availability was significant only in determining how total biomass responded to defoliation. Fertilized saplings were able to tolerate 25% defoliation without reduction in total biomass, but nonfertilized saplings were not. The interaction between defoliation and fertilization disappeared in the second growing season after the defoliation. Saplings were not able to compensate for 75% defoliation in terms of total biomass or for 100% defoliation in terms of growth and branching even in 2 years' recovery time. In stemwood, complete defoliation reduced growth ring width and vessel diameter simultaneously and also induced a narrow zone of secondary xylem with defects. Our results suggest that defoliation level and recovery time played a crucial role in compensatory growth of birch saplings, while nutrient availability had a minor role.

Climate signals from intra-annual wood density fluctuations in Abies durangensis

IAWA Journal ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 276-287 ◽  
Author(s):  
Marcos González-Cásares ◽  
Marín Pompa-García ◽  
Alejandro Venegas-González
Keyword(s):  
Wood Density ◽  
Drought Index ◽  
Growth Ring ◽  
Ring Width ◽  
Climatic Conditions ◽  
Density Fluctuations ◽  
Growth Ring Width ◽  
Density Values ◽  
Climate Signals ◽  
Hydroclimatic Variables

ABSTRACTOngoing climate change is expected to alter forests by affecting forest productivity, with implications for the ecological functions of these systems. Despite its great dendrochronological potential, little research has been conducted into the use of wood density as a proxy for determining sensitivity to climate variability in Mexico. The response of Abies durangensis Martínez, in terms of wood density and growth ring width, to monthly climatic values (mean temperature, accumulated precipitation and the drought index SPEI) was analyzed through correlation analysis. Abies durangensis presents a high response, in terms of radial growth, to climatic conditions. Tree-ring widths are more sensitive to hydroclimatic variables, whereas wood density values are more sensitive to temperature. In particular, mean (MeanD) and minimum (MND) wood density values are more sensitive to climate than maximum (MXD). We found very marked spatial variations that indicate that A. durangensis responds differently to drought conditions depending on the indices of density.

Wood Structure and Growth Ring Width of Vital and Non-Vital Douglas Fir (Pseudotsuga Menziesii) from a Single Stand in the Netherlands

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 309-318 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
Growth Rate ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Wood Structure ◽  
Growth Reduction ◽  
External Appearance ◽  
Dead Trees ◽  
Growth Ring Width ◽  
C 50

A comparison was made of diameter growth and wood structure in 26 trees of Douglas fir of different vitality cJasses in a decJining, c. 50- years old stand in De Peel (southeastern Netherlands). Ring width patterns agree cJosely but not perfectly with vitality cJasses as estimated by external appearance of the crown. The 'diseased' vitality cJasses all show growth reductions over the last 20 to 30 years. In the most diseased cJass no wood had been formed at all at the stern base over the last 4 to 10 years. The onset of growth reduction may be connected with the effect of air pollution in the last 40 to 50 years. The most striking result was the inverse relationship between growth rate in the first 10 to 15 years of growth, and growth rate in the last decades: all trees which are healthy at present showed slow radial growth when young, and all diseased to dead trees exhibited fast growth in their youth.

Influence of xylem growth ring width and wood density on durability of oak heartwood

2008 ◽  
Vol 62 (4) ◽  
pp. 368-371 ◽  
Author(s):  
Miha Humar ◽  
Blaž Fabčič ◽  
Martin Zupančič ◽  
Franc Pohleven ◽  
Primož Oven
Keyword(s):  
Wood Density ◽  
Growth Ring ◽  
Ring Width ◽  
Growth Ring Width ◽  
Xylem Growth

Tracheid Length in Vital and Non Vital Douglas Fir (Pseudotsuga Menziesii) in the Netherlands

IAWA Journal ◽  
1990 ◽  
Vol 11 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
The Netherlands ◽  
Pseudotsuga Menziesii ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Growth Reduction ◽  
Tracheid Length ◽  
Growth Ring Width ◽  
Temporary Growth

Tracheid length in relation to growth ring width is recorded for five Douglas firs from different sites in the Netherlands. The investigated trees differed in vitality assessed by crown appearance. Non vital trees showed a growth reduction which coincides with a decrease in tracheid length. Temporary growth reductions in vital trees did not result in a decrease of tracheid length. The relations hip between tracheid length and ring width is discussed.

scholarly journals Growth ring width of Pinus Caribaea and its relationship with wood properties

2018 ◽  
Vol 46 (120) ◽  
Author(s):  
Joaquim Carlos Gonçalez ◽  
Nayara Santos ◽  
Francides Gomes da Silva Junior ◽  
Roberta Santos Souza ◽  
Marcella Hermida de Paula
Keyword(s):  
Growth Ring ◽  
Ring Width ◽  
Wood Properties ◽  
Pinus Caribaea ◽  
Growth Ring Width

Growth ofPseudotsuga menziesiiandTsuga heterophyllaseedlings along a light gradient: resource allocation and morphological acclimation

1997 ◽  
Vol 75 (9) ◽  
pp. 1424-1435 ◽  
Author(s):  
D. Mailly ◽  
J. P. Kimmins
Keyword(s):  
Leaf Morphology ◽  
Biomass Accumulation ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Low Light ◽  
Growing Seasons ◽  
Light Levels ◽  
Light Gradient ◽  
Relative Light Intensity

Silvicultural alternatives that differ in the degree of overstory removal may create shady environments that will be problematic for the regeneration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Gradients of light in the field were used to compare mortality, growth, and leaf morphological acclimation of two conifer species of contrasting shade tolerances: Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Results after two growing seasons indicated that Douglas-fir mortality occurred mainly at relative light intensity (RLI) below 20%, while western hemlock mortality was evenly distributed along the light gradient. Height, diameter, and biomass of the planted seedlings increased with increasing light for both species but at different rates, and maximum biomass accumulation always occurred in the open. Douglas-fir allocated more resources to stem biomass than western hemlock, which accumulated more foliage biomass. Increases in specific leaf area for Douglas-fir seedlings occurred at RLI ≤ 0.4 and red/far red (R/FR) ratio ≤ 0.6, which appear to be the minimal optimum light levels for growth. Conversely, western hemlock seedlings adjusted their leaf morphology in a more regular pattern, and changes were less pronounced at low light levels. These results, along with early mortality results for Douglas-fir, suggest that the most successful way to artificially regenerate this species may be by allowing at least 20% of RLI for ensuring survival and at least 40% RLI for optimum growth. Key words: light, light quality, leaf morphology, acclimation.

Distribution of juvenile wood in two stems of Larixlaricina

1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong
Keyword(s):  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Tree Level ◽  
Growth Rings ◽  
Vertical Variation ◽  
Strong Negative Correlation ◽  
Ring Number ◽  
Tracheid Length ◽  
Growth Ring Width

The distribution and vertical variation of juvenile wood was studied in an 81-year-old dominant tree and an 83-year-old suppressed tree of Larixlaricina (Du Roi) K. Koch. Two criteria, growth ring width and tracheid length, were used to demarcate the boundary of juvenile wood. The width of juvenile wood, expressed in centimetres and the number of growth rings, decreased noticeably from the base to the top of the tree. The volume of juvenile wood decreased in a similar pattern. These decreasing trends had a strong negative correlation with the year of formation of cambial initials at a given tree level. The length of these cambial initials decreased with increasing age of formation of the cambial initials. In the juvenile wood zone, there was a positive linear regression between the growth ring number (age) and the tracheid length. The slopes of these regression lines at various tree levels increased as the age of the year of formation of the cambial initials increased. At a given tree level, the length of tracheids increased from the pith to a more uniform length near the bark. However, the number of years needed to attain a more uniform tracheid length decreased from the base to the top of the tree. These relationships suggest that the formation of juvenile wood is related to the year of formation of the cambial initials. Consequently, the juvenile wood is conical in shape, tapering towards the tree top.

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