Effect of growth rate on specific gravity of East-Liaoning oak (Quercusliaotungensis) wood

1991 ◽  
Vol 21 (2) ◽  
pp. 255-260 ◽  
Author(s):  
Shu-Yin Zhang ◽  
Yuan Zhong
Keyword(s):  
Growth Rate ◽  
Specific Gravity ◽  
Juvenile Wood ◽  
Growth Ring ◽  
Ring Width ◽  
Mature Wood ◽  
Constant Growth Rate ◽  
Ring Number ◽  
Constant Growth ◽  
Effect Of Age

The effect of growth rate on the specific gravity of East-Liaoning oak (Quercusliaotungensis Koidz.) wood was studied and statistically compared with the effect of age (ring number from the pith). Results revealed that age is a decisive factor in controlling the specific gravity of wood, while effect of growth rate on specific gravity is statistically less important. Furthermore, the effect of growth rate varies with ring width range, age, and position within one growth ring (earlywood, latewood, or the whole ring). Within narrower ring widths, specific gravity increases rapidly with increasing growth rate, then more slowly as ring width increases, and when ring width is beyond a specific range, specific gravity remains more or less constant. Growth rate shows little effect on specific gravity of juvenile wood, but with increasing age, the effect increases gradually to reach a significant level in mature wood. Growth rate does not affect specific gravity of latewood significantly, but it shows a greater effect on specific gravity of the whole ring.

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.

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.

Maturation Rate of Tracheid Lengthening in Slow-Grown Young Sugi (Cryptomeria Japonica) Trees

IAWA Journal ◽  
1993 ◽  
Vol 14 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Takafumi Kubo ◽  
Miwako Koyama
Keyword(s):  
Growth Rate ◽  
Cryptomeria Japonica ◽  
Radial Growth ◽  
Juvenile Wood ◽  
Ring Width ◽  
Mature Wood ◽  
Annual Rings ◽  
Tracheid Length ◽  
Rate Of Increase ◽  
Maturation Rate

Maturation rate, the rate of increase in tracheid length in juvenile wood, was examined in sugi (Cryptomeria japonica D. Don) saplings grown for five years under different shading conditions: 10%, 20% 40% and 100 % of relative illumination intensity. The lowest photointensity dramatically suppressed radial growth and slowed tracheid lengthening. Radial variation of tracheid length within the stem was associated with distance from the pith, rather than the number of annual rings from the pith. Furthermore, maturation rate was closely related to the rate of the radial growth, which changed proportionally with growth rate below a 2-3 mm ring width. A lower maturation rate of tracheid length is associated with a delay in the transition from juvenile to mature wood.

scholarly journals Effect of growth rate on the physical and mechanical properties of Douglas-fir in western Europe

2017 ◽  
Vol 47 (8) ◽  
pp. 1056-1065 ◽  
Author(s):  
C. Pollet ◽  
J.-M. Henin ◽  
J. Hébert ◽  
B. Jourez
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Management Practices ◽  
Juvenile Wood ◽  
Ring Width ◽  
Physical And Mechanical Properties ◽  
Douglas Fir ◽  
Mature Wood ◽  
Cambial Age ◽  
The Impact

To quantify the impact of forest management practices and tree growth rate on the potential uses of Douglas-fir wood, nine physico-mechanical properties were studied on more than 1250 standardized clear specimens. These were collected from trees cut in 11 even-aged stands (six trees per stand) located in Wallonia (southern Belgium). Stands were 40 to 69 years old, and mean tree girth was ca. 150 cm. Mean ring width of the 66 trees ranged from 3 to more than 7 mm. Statistical analysis showed significant but weak effects of ring width on the studied properties. Considered jointly, mean ring width and cambial age of the test specimens only explained 28% to 40% of the variability of their properties. Also, when ring width increases, these properties display higher decreases in juvenile wood than in mature wood. From a technological standpoint, maintaining mean ring width under 4 mm in juvenile wood and 6 mm in mature wood should accommodate all potential uses of Douglas-fir wood. However, considering that density appeared to be the main driver of wood properties, our results and the literature corroborate the importance of genetic selection as a complement to silvicultural measures to improve or guarantee the technological properties of Douglas-fir wood.

scholarly journals Breeding records of Leptotila rufaxilla (Aves: Columbidae) in southwestern Brazilian Amazon with notes on nesting in some regions of occurrence

2021 ◽  
Vol 28 (3) ◽  
pp. e18793
Author(s):  
Jônatas Lima ◽  
Railene Almeida ◽  
Edson Guilherme
Keyword(s):  
Growth Rate ◽  
Brazilian Amazon ◽  
Nesting Success ◽  
Daily Survival Rate ◽  
Forest Fragment ◽  
Lowland Forest ◽  
Constant Growth Rate ◽  
Nestling Period ◽  
Constant Growth ◽  
Southwestern Amazonia

We present new aspects of breeding biology of Gray-fronted Dove Leptotila rufaxilla, from five nests found between 2012 and 2014 in a lowland forest fragment in southwestern Brazil. The nests simple/platform shape were built at a mean height of 1.90 m above ground. The clutch size was two eggs white and elliptic, incubated for 15 days (based on three nests). We recorded predation in two nests still in incubation phase. Minimum hatch weight of nestlings was 10 g and young fledged with a mean mass of 56 g. The constant growth rate (K) of nestlings was 0.40 with a growth asymptote of 60.7 g. Daily survival rate, Mayfield and apparent nesting success in the incubation period was 90, 20 and 56%, respectively, while in the nestling period were all 100%. Our data and the contribution of citizen science showed that L. rufaxilla breeds over the year, mainly in the rainy season, both in southwestern Amazonia and in other regions of occurrence.

Growth and Evaluation of [AFeOx/REFeO3] (A=Ca, Sr, RE=La, Bi) Superlattices by Pulsed Laser Deposition Method Using High Density Targets Prepared by Pechini Method

2012 ◽  
Vol 1454 ◽  
pp. 161-166 ◽  
Author(s):  
Nobuyuki Iwata ◽  
Yuta Watabe ◽  
Yoshito Tsuchiya ◽  
Kento. Norota ◽  
Takuya Hashimoto ◽  
...  
Keyword(s):  
Growth Rate ◽  
Flat Surface ◽  
Pechini Method ◽  
Laser Deposition ◽  
Growth Constant ◽  
Constant Growth Rate ◽  
X Ray ◽  
Flat Interface ◽  
Reference Layer ◽  
Constant Growth

ABSTRACTThe LaFeO3 and CaFeOX layers are grown using highly dense target prepared by Pechini method, with which accurate growth rate is achieved. Since the LaFeO3demonstrates the obvious RHEED oscillation until the end of growth, constant growth rate, and the step-terraces structure, the LFO is employed as a buffer and/or reference layer to determine the required pulses to deposit the thickness we desire in the superlattice. Superlattices show the clear satellite peaks and Laue oscillation in the XRD spectra as well as the oscillations caused by the film thickness with a flat surface and superstructure with a flat interface in the x-ray reflection spectrum. The streaky RHEED patterns and step-terraces surface are consistent with the results of spectra using x-ray.

scholarly journals Constant Growth Rate Can Be Supported by Decreasing Energy Flux and Increasing Aerobic Glycolysis

Cell Reports ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 705-714 ◽  
Author(s):  
Nikolai Slavov ◽  
Bogdan A. Budnik ◽  
David Schwab ◽  
Edoardo M. Airoldi ◽  
Alexander van Oudenaarden
Keyword(s):  
Growth Rate ◽  
Energy Flux ◽  
Aerobic Glycolysis ◽  
Constant Growth Rate ◽  
Constant Growth

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.

scholarly journals General formulation of Luria-Delbrück distribution of the number of mutants

2015 ◽  
Author(s):  
bahram houchmandzadeh
Keyword(s):  
Growth Rate ◽  
Evolutionary Theory ◽  
Growth Function ◽  
Considerable Effort ◽  
Constant Growth Rate ◽  
Stochastic Growth ◽  
The Subject ◽  
Constant Growth

Abstract The Luria-Delbrück experiment is a cornerstone of evolutionary theory, demonstrating the randomness of mutations before selection. The distribution of the number of mutants in this experiment has been the subject of intense investigation during the last 70 years. Despite this considerable effort, most of the results have been obtained under the assumption of constant growth rate, which is far from the experimental condition. We derive here the properties of this distribution for arbitrary growth function, for both the deterministic and stochastic growth of the mutants. The derivation we propose is surprisingly simple and versatile, allowing many generalizations to be taken easily into account.

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