Branches versus stems in woody plants: control of branch diameter growth and angle

1998 ◽  
Vol 76 (11) ◽  
pp. 1852-1856 ◽  
Author(s):  
Brayton F Wilson
Keyword(s):  
Acer Rubrum ◽  
Growth Stress ◽  
Diameter Growth ◽  
Reaction Wood ◽  
Differential Growth ◽  
Lateral Shoot ◽  
Branch Diameter ◽  
Growth Stresses ◽  
Branch Angle ◽  
Apical Control

The results of three studies at different stages of branch development demonstrated the importance of apical control of diameter growth in both stem formation and branch angle. Diameter growth is controlled by competition between branches and the stem for branch-produced photosynthate. Apical control of branch angle occurs only in species that can produce differential growth stresses. In those species, upward bending is largely regulated by the amount of branch diameter growth. The first study followed stem formation from current shoots in Kalmia latifolia L., a shrub without terminal buds or apical control of branch angle. When several current or older shoots were competing, the longest, most distal lateral shoot usually became the stem. Shoot angle was poorly correlated with eventual dominance. A more proximal lateral shoot on the underside of a leaning parent became the longest, dominant lateral in 24% of the parent shoots. The second study used stem girdles to test the hypothesis that the subjacent stem competes with the branch for branch-produced photosynthate. Results from Pinus strobus L. supported the hypothesis, but results from Betula lenta L. and Acer rubrum L. did not. The third study removed apical control from branches of six forest-shrub species by cutting off the stem above the branch. Branches of all species increased diameter growth after cutting the stem, but only branches of Ilex verticillata (L.) Gray, Hamamelis virginiana L., and Cornus amomum Mill. developed differential growth stress and bent upward. Treated branches of Gaylusaccia baccata (Wang.) K. Koch, Viburnum cassinoides L., and K. latifolia sagged as much as controls.Key words: apical control, diameter growth, branch angle, growth stress, reaction wood.

A GENERAL THEORY FOR THE ORIGIN OF GROWTH STRESSES IN REACTION WOOD: HOW TREES STAY UPRIGHT

IAWA Journal ◽  
2001 ◽  
Vol 22 (3) ◽  
pp. 205-212 ◽  
Author(s):  
Richard Kenneth Bamber
Keyword(s):  
General Theory ◽  
Compression Wood ◽  
Tensile Force ◽  
Compressive Force ◽  
Growth Stress ◽  
Cellulose Microfibrils ◽  
Reaction Wood ◽  
Growth Stresses ◽  
Helical Springs ◽  
Prevailing View

A general theory for the origin of growth stresses in the reaction wood of trees is presented. In both gymnosperms and arboreal dicotyledons, stress is considered to arise from the cellulosic component of the wood. It is suggested that in gymnosperms, cellulose microfibrils behave as helical springs. The helical springs are thought to be laid down in a compressed state and thus exert a compressive force which acts to right or stabilise the tree.In arboreal dicotyledons the cellulose microfibrils are laid down as extended, longitudinally oriented springs and thus exert a tensile force tending to right or stabilise the tree.Contrary to the prevailing view, lignin is not considered to be involved in the generation of growth stress in reaction wood. It is suggested that the sole function of lignin is to cement the cellulosic constituents into a whole, thus ensuring the transmission of stresses through the wood. The low values of lignin often reported from tension wood and especially from gelatinous fibres is seen as a mechanism to facilitate the contraction of microfibils thus maximising longitudinal tensile stress. The high values of lignin in of compression wood is seen as a mechanism to increase the compressive strength of compression wood.

Negative gravitropism of Ginkgo biloba: growth stress and reaction wood formation

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Tatsuya Shirai ◽  
Hiroyuki Yamamoto ◽  
Miyuki Matsuo ◽  
Mikuri Inatsugu ◽  
Masato Yoshida ◽  
...  
Keyword(s):  
Ginkgo Biloba ◽  
Lignin Content ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Wood Formation ◽  
Growth Stress ◽  
Reaction Wood ◽  
Cellulose Content ◽  
S2 Layer ◽  
Negative Gravitropism

Abstract Ginkgo (Ginkgo biloba L.) forms thick, lignified secondary xylem in the cylindrical stem as in Pinales (commonly called conifers), although it has more phylogenetic affinity to Cycadales than to conifers. Ginkgo forms compression wood-like (CW-like) reaction wood (RW) in its inclined stem as it is the case in conifers. However, the distribution of growth stress is not yet investigated in the RW of ginkgo, and thus this tissue resulting from negative gravitropism is still waiting for closer consideration. The present study intended to fill this gap. It has been demonstrated that, indeed, ginkgo forms RW tissue on the lower side of the inclined stem, where the compressive growth stress (CGS) was generated. In the RW, the micorofibril angle in the S2 layer, the air-dried density, and the lignin content increased, whereas the cellulose content decreased. These data are quite similar to those of conifer CWs. The multiple linear regression analysis revealed that the CGS is significantly correlated by the changes in the aforementioned parameters. It can be safely concluded that the negative gravitropism of ginkgo is very similar to that of conifers.

Precommercial Thinning and Pruning of Appalachian Stump Sprouts—10-Year Results

1988 ◽  
Vol 12 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Neil I. Lamson
Keyword(s):  
Acer Rubrum ◽  
Prunus Serotina ◽  
Maximum Diameter ◽  
Diameter Growth ◽  
Red Oak ◽  
Black Cherry ◽  
Northern Red Oak ◽  
Red Maple ◽  
Growth Data ◽  
Precommercial Thinning

Abstract In northern West Virginia, 7-year-old American basswood (Tilia americana L.) and 12-year-old red maple (Acer rubrum L.), black cherry (Prunus serotina Ehrh.), and northern red oak (Quercus rubra L.) stump sprout clumps received one of four treatments: unthinned control; thinned to the best one or two codominant sprouts per clump; branch pruned up to 75% of total height; or thinned plus pruned. Analysis of 10-year growth data showed that height growth was not affected by any of the treatments. For all species, pruning slightly increased the length of clear stem and decreased periodic diameter growth. Thinning increased survival of basswood, red oak, and red maple crop stems. Thinning increased the 10-year diameter growth by 0.1 to 0.8 in. Recommendations for thinning 10- to 20-year-old sprout clumps are presented. Pruning is not recommended. In order to maintain maximum diameter growth, thinning individual sprout clumps should be followed by stand crop tree release in about 10 years. South. J. Appl. For. 12(1):23-27.

Ethylene, gibberellins, auxin and the apical control of branch angle in a conifer, Cupressus arizonica

Planta ◽  
1980 ◽  
Vol 148 (1) ◽  
pp. 64-68 ◽  
Author(s):  
T. J. Blake ◽  
R. P. Pharis ◽  
D. M. Reid
Keyword(s):  
Branch Angle ◽  
Apical Control ◽  
Cupressus Arizonica

Predicting branch angle and branch diameter of Scots pine from usual tree measurements and stand structural information

1998 ◽  
Vol 28 (11) ◽  
pp. 1686-1696 ◽  
Author(s):  
Harri Mäkinen ◽  
Francis Colin
Keyword(s):  
Scots Pine ◽  
Structural Information ◽  
Stand Density ◽  
Random Tree ◽  
Tree Level ◽  
Variance Component Model ◽  
Detailed Knowledge ◽  
Branch Diameter ◽  
Branch Angle ◽  
Tree Effect

A total of 19 thinning experiments were performed in southern and central Finland to study branchiness of Scots pine (Pinus sylvestris L.). Data were collected from 229 trees of different ages and canopy positions growing on sites of different fertility and thinned to different stand densities. They were used to construct models for predicting vertical trends of branch angle and branch diameter along the stem. By using the variance component model, it was possible to separate the stand-, plot-, and tree-level variations of the dependent variables. However, as the random stand and plot effects were small, they were ignored. The random tree effect of the branch angle model was slightly higher compared with the random tree effect of the branch diameter model. Branch angle increased rapidly in the upper part of the crown, but the increase levelled off in the lower part of the stem. Branch diameter increased from the stem apex to the lower part of the crown and then decreased again towards the base of the tree. Stand density measures were significant variables in the models of branch angle and branch diameter. However, they could be excluded without loss of accuracy if variables describing dimensions of the tree were used as independent variables. Relative crown length and stem diameter were adequate tree-level variables for describing branch characteristics. Validation of the models constructed without variables describing stand density revealed no biased behaviour with respect to stand density. It was concluded that branch characteristics can be predicted from the measurement of some tree-level variables without detailed knowledge of the stand history.

scholarly journals Growth Periodicity for Container-Grown Red and Freeman Maple Cultivars in AHS Heat-Zone 8

1999 ◽  
Vol 17 (3) ◽  
pp. 141-146
Author(s):  
Jeff L. Sibley ◽  
John M. Ruter ◽  
D. Joseph Eakes
Keyword(s):  
Root Growth ◽  
Interspecific Cross ◽  
Acer Rubrum ◽  
Growth Modeling ◽  
Growth Patterns ◽  
Diameter Growth ◽  
Red Maple ◽  
Heat Zone ◽  
Growth Increase ◽  
Growth Periodicity

Abstract Growth patterns of seven red maple (Acer rubrum L.) and three Freeman maple (Acer x freemanii E. Murray) cultivars grown in containers in Alabama were evaluated using monthly destructive harvests. The effectiveness of a growth modeling technique not previously described is demonstrated using the data presented for both the Freeman maple (red maple xsilver maple interspecific cross) and red maple categories. Freeman maple cultivars ‘Armstrong’, ‘Celzam’ (Celebration™), and ‘Jeffersred’ (Autumn Blaze™); and red maple cultivars ‘Autumn Flame’, ‘Fairview Flame’, ‘Landsburg’ (Firedance™), ‘Franksred’ (Red Sunset™), ‘Olson’ (Northfire™), ‘Northwood’, and ‘October Glory®’ were studied. Uniform liners of each cultivar were planted in 9.1-liter (#3) containers in March 1996. More than 75% of seasonal height and diameter growth was complete for most cultivars before mid-August, while only 25% of root growth had occurred by the end of August. The remaining 75% of root growth occurred from August through November. The greatest overall growth (based on height, diameter, and root growth increase) was for ‘Autumn Flame’ and ‘October Glory®’, both red maple cultivars; and Freeman maple cultivars ‘Celzam’ and ‘Jeffersred’. The least overall growth (based on height, diameter, and root growth increase), was for red maple cultivars ‘Northwood’ and ‘Landsburg’.

scholarly journals Russeting and Relative Growth Rate Are Positively Related in ‘Conference’ and ‘Condo’ Pear

HortScience ◽  
2014 ◽  
Vol 49 (6) ◽  
pp. 746-749 ◽  
Author(s):  
Johannes Daniel Scharwies ◽  
Eckhard Grimm ◽  
Moritz Knoche
Keyword(s):  
Surface Area ◽  
Early Development ◽  
Growth Rates ◽  
Neck Region ◽  
Prolate Spheroid ◽  
Pear Fruit ◽  
Differential Growth ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growth Stresses

Russeting is an important surface disorder in fruit and mechanical growth stresses, among other factors, are considered causal in russet induction. To test this hypothesis, fruit development and russeting were monitored on a whole fruit level and also in the calyx, cheek, and neck region of developing ‘Conference’ and ‘Condo’ pear fruit (Pyrus communis L.). To quantify growth, the pear fruit was geometrically modeled as approximating to half of a prolate spheroid for the calyx region and two truncated cones for the cheek and neck regions, respectively. Mass and surface area of ‘Conference’ and ‘Condo’ fruit increased in a single sigmoidal pattern with time. Fruit volume, determined by buoyancy, using a hydrostatic balance, and the Archimedes’ principle was closely related to that predicted by the model from fruit geometry. Growth rates of surface area in ‘Conference’ and ‘Condo’ peaked at ≈90 and 100 days after full bloom (DAFB), respectively, and were highest in the calyx followed by the cheek and neck regions. Relative growth rates, calculated by dividing growth rates by the absolute surface area present at that time, were at maximum during early development and thereafter continuously declined. In general, relative growth rates were highest for the cheek region, intermediate in the calyx, and lowest for the neck. ‘Conference’ fruit were always more russeted than ‘Condo’ with russeting generally decreasing from calyx to cheek and neck. Furthermore, russeting increased rapidly in ‘Conference’ during early development until ≈70 DAFB, particularly in the calyx and cheek regions and, to a lesser extent, in the neck region. There was little change in russeting after ≈70 DAFB. Plotting rates of russeting vs. relative growth rates in surface area indicate a positive and common relationship across regions where russeting increased when relative growth rates exceeded 0.03/day. Thus, differential growth rates between regions within ‘Conference’ or ‘Condo’, but not across the two cultivars, accounted for topical differences in russeting.

scholarly journals Growth of Newly Established Tilia platyphyllos ‘Rubra’ Roadside Trees in Response to Weed Control and Pruning

2010 ◽  
Vol 36 (1) ◽  
pp. 35-40
Author(s):  
Palle Kristoffersen ◽  
Oliver Bühler ◽  
Søren Larsen ◽  
Thomas Randrup
Keyword(s):  
Weed Control ◽  
Untreated Control ◽  
Early Stage ◽  
Management Practice ◽  
Diameter Ratio ◽  
Diameter Growth ◽  
Branch Diameter ◽  
Diameter Increment ◽  
Tilia Platyphyllos ◽  
Stem Diameter Growth

This tree establishment study investigates the effect of weed control and pruning treatments on stem and branch diameter increment of newly planted broad-leaved lime (Tilia platyphyllos ‘Rubra’) roadside trees. Weed control significantly increased stem circumference four years after establishment by 3.6 cm (1.4 in) from 24.5 cm (9.7 in, untreated control) to 28.1 cm (11.1 in). In terms of Danish nursery sales prices, this corresponds to an increase of tree cash value of 1201 DKK (160.90 €, 235.40 US$) per tree. Calculating with 400 DKK (53.60 €, 78.40 US$) as cost for contract weeding per hour, this corresponds to 0.75 hours per tree per year for a period of four years. In addition to weed control treatments, trees were pruned at establishment, two years after establishment, or at both times. None of the pruning treatments affected stem diameter growth, but branch diameter and branch:stem diameter ratio were significantly reduced by all pruning treatments. Branch diameter ranged from 40.1 mm (1.6 in) on unpruned trees to 34.6 mm (1.4 in on trees pruned both times. Branch:stem diameter ratio ranged from 0.54 on unpruned trees to 0.49 on trees pruned both times. In consequence, weed control is recommended as a strong management practice. Mild pruning is also considered advisable, if structural crown problems can be avoided at an early stage, and if the tree has to be prepared for later pruning operations.

Silvicultural control of mechanical stresses in trees

1988 ◽  
Vol 18 (10) ◽  
pp. 1215-1225 ◽  
Author(s):  
Hans Kubler
Keyword(s):  
Spatial Distribution ◽  
Mechanical Stress ◽  
High Stress ◽  
Growth Conditions ◽  
Mechanical Stresses ◽  
Reaction Wood ◽  
Prevailing Wind ◽  
Growth Stresses ◽  
Stable Growth ◽  
Steep Slopes

Mechanical stress generated by growing wood cells causes heart checks in the ends of timber, while lumber end-splits and warps. It is not possible to prevent these growth stresses but they can be minimized. Trees generate relatively high stress in order to bend stems and branches into positions more favorable for the tree, as is known from reaction wood, whose growth stresses are extremely high. One controls the stresses by giving trees no reason to reorient themselves, that is, by providing stable growth conditions. To this end, trees should have sufficient, uniform light, and where light is scarce, as in understories, one-sided light changes have to be avoided. In particular, the spatial distribution of trees in the stand should be uniform; multistoried forests are preferable to single-storied, even-aged plantations. The stands should be thinned slightly, frequently, and uniformly, rather than haphazardly and severely after long periods. In areas with strong prevailing wind, close spacing may minimize the stresses, whereas on steep slopes wide spacing appears to be preferable.

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