scholarly journals METHODS FOR ALLEVIATION AND REDUCTION OF THE EFFECTS OF GROWTH STRESSES IN Eucalyptus urophylla

2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Juliana Cristina da Silva ◽  
Ana Márcia Macedo Ladeira Carvalho ◽  
Bruno de Freitas Homem de Faria
Keyword(s):  
Tree Growth ◽  
Growth Stress ◽  
Efficient Technique ◽  
Eucalyptus Urophylla ◽  
Herbicide Application ◽  
Growth Stresses ◽  
Cracking Control

ABSTRACT There are many species of the Eucalyptus genus presents high levels of the growth stress. These stresses are mechanical efforts generated during the tree growth to help maintaining the balance of the cup in response to environmental and silvicultural agents. The stresses are responsible for the cracks of tops and for the warp after unfolding. The objective of this study was to test five different methods to minimize the effects of growth stress on the production of Eucalyptus urophylla sawlogs. The boards produced were then evaluated and measured for cracking, arching, curvature and cupping. The treatment with herbicide presented the smallest medium indexes of cracking (16.63 cm) and of arching (0.23 mm.m-1), while the medium curvature was smaller than observed in boards unfolded in 72 hours after the reduction of the trees (0.88 mm.m-1). Unfolding after ten days of harvesting represented the less efficient technique in the cracking control, curvature and arching. The cupping was not observed during boards processing. The herbicide application was more efficient in the reduction of the effects of the growth tensions.

scholarly journals METHODS FOR ALLEVIATION AND REDUCTION OF THE EFFECTS OF GROWTH STRESSES IN Eucalyptus urophylla

2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Juliana Cristina da Silva ◽  
Ana Márcia Macedo Ladeira Carvalho ◽  
Bruno de Freitas Homem de Faria
Keyword(s):  
Tree Growth ◽  
Growth Stress ◽  
Efficient Technique ◽  
Eucalyptus Urophylla ◽  
Herbicide Application ◽  
Growth Stresses ◽  
Cracking Control

ABSTRACT There are many species of the Eucalyptus genus presents high levels of the growth stress. These stresses are mechanical efforts generated during the tree growth to help maintaining the balance of the cup in response to environmental and silvicultural agents. The stresses are responsible for the cracks of tops and for the warp after unfolding. The objective of this study was to test five different methods to minimize the effects of growth stress on the production of Eucalyptus urophylla sawlogs. The boards produced were then evaluated and measured for cracking, arching, curvature and cupping. The treatment with herbicide presented the smallest medium indexes of cracking (16.63 cm) and of arching (0.23 mm.m-1), while the medium curvature was smaller than observed in boards unfolded in 72 hours after the reduction of the trees (0.88 mm.m-1). Unfolding after ten days of harvesting represented the less efficient technique in the cracking control, curvature and arching. The cupping was not observed during boards processing. The herbicide application was more efficient in the reduction of the effects of the growth tensions.

Tree growth stresses—Part IV: Visco-elastic strain recovery

1972 ◽  
Vol 6 (2) ◽  
pp. 95-120 ◽  
Author(s):  
J. D. Boyd ◽  
K. B. Schuster
Keyword(s):  
Tree Growth ◽  
Elastic Strain ◽  
Strain Recovery ◽  
Growth Stresses

scholarly journals Site Classification of Eucalyptus urophylla × Eucalyptus grandis Plantations in China

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 871
Author(s):  
Haifei Lu ◽  
Jianmin Xu ◽  
Guangyou Li ◽  
Wangshu Liu
Keyword(s):  
Tree Growth ◽  
Soil Depth ◽  
Eucalyptus Grandis ◽  
Growth Potential ◽  
Slope Position ◽  
Purple Soil ◽  
Eucalyptus Urophylla ◽  
Site Factors ◽  
Quantification Theory ◽  
The Relationship

Background and Objectives: It is important to match species needs with site conditions for sustainable forestry. In Eucalyptus urophylla × Eucalyptus grandis plantations in southern Yunnan, China, species-site mismatches have led to inappropriate expansion and management, which has degraded forests and decreased efficiency in plantation production. Further research is needed to understand the relationship between tree growth and site productivity. We empirically explored site features and classified site types within these plantations in southern Yunnan. Our objective was to develop a theoretical basis for improving site selection for afforestation, and to establish intensive management in that region. Materials and Methods: 130 standard plots were set up in 1−15-year-old eucalyptus plantations in Pu’er and Lincang. We used quantification theory to examine the relationship between dominant tree growth traits and site factors. Hierarchical cluster analysis and canonical correlation analysis were applied to classify sites and evaluate the growth potential of E. urophylla × E. grandis plantations, respectively. Results: The multiple correlation coefficient between eight site factors (altitude, slope, slope position, aspect, soil depth, texture, bulk density, and litter thickness) and the quantitative growth of the dominant tree was 0.834 (p < 0.05). Slope position, altitude, and soil depth were the main factors contributing to the variation in stand growth. Plantation growth was best on lower slopes at relatively low altitude, where thick and weathered red soil layers existed. Conversely, the poorest plantations were located on upper slopes at higher altitude, with a thin semi-weathered purple soil layer. The soil factors total nitrogen (N) and potassium (K), trace boron (B), copper (Cu), and zinc (Zn) content, available phosphorous (P), and organic matter content in the soil influenced plantation growth. Conclusions. The addition of N, P, and K fertilizer as well as trace elements such as B, Cu, and Zn can promote the productivity of these plantations.

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.

Measurement of surface growth stress in Eucalyptus nitens Maiden by splitting a log along its axis

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Shakti Chauhan ◽  
Kenneth Entwistle
Keyword(s):  
Splitting Method ◽  
Circular Cross Section ◽  
Growth Stress ◽  
Surface Growth ◽  
Longitudinal Growth ◽  
Growth Strain ◽  
Eucalyptus Nitens ◽  
Growth Stresses ◽  
The Relationship ◽  
Longitudinal Growth Strain

Abstract When a log is sawn along the length, an outward bending or deflection of two half rounds arises from the release of growth stresses in the log. The relationship between this outward bending and the peripheral longitudinal growth strain in logs from a 10-year-old Eucalyptus nitens plantation was investigated. In total, 63 trees were felled and two logs (one bottom and an upper log) were cut from each felled tree. A strong association was observed between the measured longitudinal growth strain and the outward bending produced by splitting the log along its axis. A mathematical model was developed that enables calculation of the relationship between the surface axial growth stress and the opening of the split log. This involves calculation of the lateral deflection of a tapered cantilever beam of semi-circular cross-section under a known bending moment. The relationship between the opening of the slit log and the surface axial stress showed good agreement with the measured data on 126 logs. The model equation is effective in predicting the growth stress from the magnitude of the log distortion. This log sawing or splitting method is quick and reliable for assessing the surface growth stresses in small diameter trees. It could have potential in breeding programs for identifying families or clones for low-growth stresses of superior eucalypts for sawn timber production.

Native Hardwood Tree Seedling Establishment Following Invasive Autumn-Olive (Elaeagnus umbellata) Removal on a Reclaimed Coal Mine

2018 ◽  
Vol 11 (3) ◽  
pp. 155-161
Author(s):  
Morgan E. Franke ◽  
Carl Zipper ◽  
Jacob N. Barney
Keyword(s):  
Tree Growth ◽  
Management Practices ◽  
Growing Season ◽  
The United States ◽  
Herbicide Application ◽  
Elaeagnus Umbellata ◽  
Autumn Olive ◽  
Native Trees ◽  
Tree Survival ◽  
Native Tree

AbstractThe Appalachian region of the United States is home to the largest temperate deciduous forest in the world, though surface mining has caused significant forest loss. Many former coal mines are now dominated by invasive plants, which often inhibit establishment of desirable species, especially slower-growing native trees. Autumn-olive (Elaeagnus umbellataThunb.) is a nonnative, nitrogen-fixing shrub that was historically planted on former coalfields, but now impedes reclamation. To better understand the influence ofE. umbellatamanagement practices on hardwood establishment, we evaluated two common management practices: cutting and cut stump herbicide treatment. Planted native tree species, including black cherry (Prunus serotinaEhrh.), pin oak (Quercus palustrisMünchh.), and red maple (Acer rubrumL.), were monitored for survival and performance over two growing seasons followingE. umbellataremoval. In each plot, we also measured plant-available nitrate (NO3−) and ammonium (NH4+) in soils using ionic exchange membranes. At the end of the first growing season, native tree survival was high, and the presence or absence ofE. umbellatahad little effect on tree survival or growth, despite the higher plant-available nitrate whereE. umbellatawas present. By the end of the second growing season, native tree survival dropped to 20% to 60% and varied amongE. umbellatatreatments. Survival was highest whenE. umbellatawas cut and treated with herbicide, though tree growth was similar across all treatments withoutE. umbellata. When establishing native trees to replaceE. umbellata, cutting and herbicide application treatment of the invader resulted in the highest overall efficacy (100% control), though the most cost-effective method may be to simply cut mature stands despite regrowth, as this resulted in equivalent native tree growth over 2 yr. While this allowedE. umbellataregeneration, it provided sufficient invader control to allow initial tree establishment. Cutting and herbicide application treatment resulted in lessE. umbellataregeneration and appears to provide greater assurance that established trees will persist over the long term.

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.

scholarly journals Apple and Peach Orchard Establishment Following Multi-year Use of Diuron, Simazine, and Terbacil

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1211-1213 ◽  
Author(s):  
Thomas Tworkoski ◽  
Stephen Miller
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Tree Growth ◽  
Prunus Persica ◽  
Apple Tree ◽  
Fruit Tree ◽  
Peach Tree ◽  
Herbicide Application ◽  
Herbicide Treatments ◽  
Peach Orchard

Combinations of diuron, simazine, and terbacil were applied every year over 15 and 16 years to the same plots. Apple (Malu×domestica Borkh.) and peach (Prunus persica L.) trees then were planted 1 and 2 years following the last herbicide application. In general, apple-tree growth was not affected, but peach tree growth was reduced by some herbicide treatments. Peach-tree growth was reduced in plots treated with terbacil and soil organic matter was lowest in these plots. Time of last herbicide treatment did not affect apple- or peach-tree growth. The results indicated that reduced fruit-tree growth was associated with reduced soil organic matter and that residual terbacil may have inhibited peach-tree growth. Chemical names used: N′-(3,4-dichlorphenyl)-N,N-dimethylurea (diuron); 6-chloro-N,N′-diethyl-1,3,5-triazine-2,4-diamine (simazine); 5-chloro-3-(1,1-dimethylethyl)-6-methyl-2,4(1H,3H)-pyrimidinedione (terbacil).

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