scholarly journals The Effects of Pruning on Drag and Bending Moment of Shade Trees

2008 ◽  
Vol 34 (4) ◽  
pp. 207-215
Author(s):  
Michael Pavlis ◽  
Brian Kane ◽  
J. Roger Harris ◽  
John Seiler
Keyword(s):  
Center Of Pressure ◽  
Bending Moment ◽  
National Standards ◽  
Shade Trees ◽  
White Oak ◽  
Practical Applications ◽  
Before And After ◽  
Quercus Bicolor ◽  
Swamp White Oak ◽  
Simulated Wind

Arborists assume that pruning can help reduce the risk of tree failure by reducing the pressure exerted on trunks by wind (drag-induced bending moment), but there are few studies that quantify this effect. We simulated wind by driving trees in the back of a pickup truck from 0 to 24.5 m/s (0 to 55 mph) and measured drag-induced bending moment as well as tree morphometric data for Freeman maple (Acer × freemanii), swamp white oak (Quercus bicolor Willd.), and shingle oak (Quercus imbricaria Michx.). Measurements were taken before and after application of one of three American National Standards Institute A300 pruning types (raising, reduction pruning, thinning). Reduction of drag-induced bending moment differed by pruning type, largely in accordance with the mass of foliage and twigs removed. The effectiveness of pruning types was also species-dependent because crown architecture affected how much mass each pruning type removed. In general, per unit of mass removed, reduction pruning more effectively reduced the drag-induced bending moment than thinning or raising. Reduction pruning reduced the center of pressure height and, presumably, increased crown porosity after pruning. Prediction of the reduction of drag-induced bending moment was not reliable based on reduction in crown area after pruning. We discuss the practical applications of our findings.

Comparing the Missouri Gravel Bed and a Wood Chip Production Method for Tree Growth

2019 ◽  
Vol 45 (6) ◽  
Author(s):  
Kelby Fite ◽  
Liza Holmes ◽  
Elden LeBrun
Keyword(s):  
Wood Chip ◽  
Production Method ◽  
White Oak ◽  
Gravel Bed ◽  
System A ◽  
Nursery Production ◽  
Quercus Bicolor ◽  
Root Stock ◽  
Swamp White Oak ◽  
Bare Root

Tree root defects from current nursery production practices influence short- and long-term tree performance and survivability. The Missouri Gravel Bed (MGB) system, a production method using gravel as a substrate, has been used to prevent many of these defects from occurring. MGB production involves planting bare root stock into a bed of gravel with frequent drip irrigation in order to produce a root system with relatively few defects. MGB production methods have also been purported to allow for summer transplanting of many species, as opposed to traditional dormant transplanting.Because gravel has low water- and nutrient-holding capacity, biochar (5% by volume) was incorporated into one plot as a possible means of improving both water- and nutrient-holding capacity over gravel alone. Wood chip mulch was also investigated as a growing substrate in place of the gravel in a growing system. In 2015, three species, Quercus bicolor (swamp white oak), Taxodium distichum (baldcypress), and Tilia cordata (littleleaf linden), were studied in pea gravel (PG), biochar-amended pea gravel (BC), and wood chip mulch bed (MB) growing environments. Very few differences occurred over the growing season with above- or belowground parameters indicating that the minimal-to-no-cost, more readily available substrate of wood chip mulch should be considered in these growing systems.

Early responses of sapwood of Quercus bicolor to mechanical injury

1970 ◽  
Vol 48 (4) ◽  
pp. 683-686 ◽  
Author(s):  
J. F. Wardell ◽  
J. H. Hart
Keyword(s):  
Mechanical Injury ◽  
Annual Rings ◽  
Triphenyl Tetrazolium Chloride ◽  
White Oak ◽  
Tetrazolium Chloride ◽  
Starch Grains ◽  
Quercus Bicolor ◽  
Swamp White Oak ◽  
Ray Parenchyma Cells ◽  
Extraneous Material

The response of sapwood of swamp white oak (Quercus bicolor Willd.) to mechanical injury was studied over a 28-day period. In cells within 0.5 cm of a wound stimulus, starch grains disappeared and cells were unable to reduce the vital stain, triphenyl tetrazolium chloride (TTC), 8 to 10 days after mechanical injury. Extraneous material and tannins began to accumulate 10 to 12 days after mechanical injury. Nuclei began to disintegrate 12 to 14 days after mechanical injury, but some persisted throughout the period of investigation.With increasing distance from the cambium, starch grains disappeared from ray parenchyma. Cells in the annual rings of sapwood adjacent to the heartwood were unable to reduce TTC. Nuclei were present in all annual rings of sapwood but were lacking in heartwood. Tannins appeared at the heartwood boundary and accumulated in the heartwood.With respect to the criteria used, this investigation indicates that formation of discoloration in sapwood and conversion of sapwood to heartwood appear similar.

scholarly journals The Effects Of Pruning Type On Wind Loading Of Acer Rubrum

2006 ◽  
Vol 32 (1) ◽  
pp. 33-40
Author(s):  
E. Thomas Smiley ◽  
Brian Kane
Keyword(s):  
Center Of Pressure ◽  
Acer Rubrum ◽  
Bending Moment ◽  
Wind Load ◽  
Wind Loading ◽  
Load Reduction ◽  
Before And After

The wind load, bending moment, height, and weight were determined for 81 red maples (Acer rubrum) before and after pruning. Trees were thinned, reduced, lion tailed, or stripped of foliage. All three pruning treatments reduced wind load significantly compared to unpruned trees at all tested velocities (11, 16, and 20 m/sec [25, 35, and 45 mph]). Reduction in wind load increased with increasing velocity. Differences in wind-load reduction between reduction pruning and thinning were not significant at any velocity. The reduction in wind load was linearly related to the amount of weight removed by pruning treatments. Compared to the same trees prior to pruning, the center of pressure height was significantly lowered on thinned and reduced trees, while the center of pressure height did not change on lion-tailed trees.

QUERCUS BICOLOR, SWAMP WHITE OAK

2014 ◽  
pp. 1307-1308
Author(s):  
Henry John Elwes ◽  
Augustine Henry
Keyword(s):  
White Oak ◽  
Quercus Bicolor ◽  
Swamp White Oak

scholarly journals Asexual Embryogenesis and Plant Regeneration from Male Catkins of Quercus

HortScience ◽  
1991 ◽  
Vol 26 (9) ◽  
pp. 1217-1218 ◽  
Author(s):  
V.M. Gingas
Keyword(s):  
Plant Regeneration ◽  
Growth Regulators ◽  
Embryogenic Callus ◽  
Dichlorophenoxyacetic Acid ◽  
Ms Medium ◽  
White Oak ◽  
Callus Proliferation ◽  
Quercus Bicolor ◽  
Swamp White Oak ◽  
Asexual Embryogenesis

Partially expanded male catkins of swamp white oak (Quercus bicolor Willd.) and red oak (Quercus rubra L.) were cultured on Murashige and Skoog (MS) medium supplemented with BA or 2,4-D. Explants on 2,4-D produced a yellow embryogenic callus originating from the junction of the pedicel and peduncle. Subsequent transfers to MS with BA and then MS without growth regulators resulted in callus proliferation. After 10 to 14 weeks in culture, white embryoids developed from the callus of Q. bicolor. Separated and individually cultured embryoids underwent direct, repetitive embryogenesis. Upon transfer to l/2-strength MS, embryoid germination and plant regeneration occurred. Callus of Q. rubra degenerated after 5 months in culture, failing to yield embryogenic structures. Chemical names used: dichlorophenoxyacetic acid (2,4-D); benzyladenine (BA).

scholarly journals Cutting Back Stock Plants Promotes Adventitious Rooting of Stems of Quercus bicolor and Quercus macrocarpa

2009 ◽  
Vol 27 (3) ◽  
pp. 159-165 ◽  
Author(s):  
J. Naalamle Amissah ◽  
Nina Bassuk
Keyword(s):  
Adventitious Rooting ◽  
Stem Cuttings ◽  
Stock Plant ◽  
White Oak ◽  
Quercus Macrocarpa ◽  
Intact Plants ◽  
Plant Group ◽  
Bur Oak ◽  
Quercus Bicolor ◽  
Swamp White Oak

Abstract Studies were conducted to investigate the severity of cutting back stock plants on adventitious rooting of layered stems and stem cuttings of Quercus bicolor Willd. (swamp white oak) and Quercus macrocarpa Michx. (bur oak). Rooting averaged 77% in Q. bicolor and 70% in Q. macrocarpa layered stems from the cutback stock plant group, compared to air layered stems from intact plants which averaged 1% in Q. bicolor and 0% in Q. macrocarpa. In another experiment cuttings were taken from three stock plant heights [4 cm (1.6 in), or 100 cm (39.4 in) stumps and intact plants ∼ 170 cm (66.9 in)] which were either etiolated or grown in natural light and rooted under mist. The best rooting (59%) and average number of roots (9.3) were found in etiolated Q. bicolor cuttings taken from 4 cm (1.6 in) stumps. Q. macrocarpa cuttings rooted poorly with only 7% of the cuttings rooting. By taking cuttings a week earlier for rooting (2 weeks, at the softwood stage), rooting in Q. macrocarpa was possible, with the best rooting (46%) found in etiolated cuttings taken from 4 cm (1.6 in) stumps. Overall, the highest rooting and greatest number of roots occurred in etiolated layers and cuttings from the 4 cm cutback group. Rooting generally increased with increasing extent of stock plant cutback

Positional influence on rooting of shoots forced from the main bole of swamp white oak and northern red oak

2003 ◽  
Vol 33 (4) ◽  
pp. 705-711 ◽  
Author(s):  
D W Fishel ◽  
J J Zaczek ◽  
J E Preece
Keyword(s):  
Vertical Gradient ◽  
Red Oak ◽  
Northern Red Oak ◽  
White Oak ◽  
Oak Trees ◽  
Shoot Production ◽  
Quercus Bicolor ◽  
Swamp White Oak ◽  
Rooting Response

The transition of ontogenetic maturity was assessed in two oak species by forcing softwood shoots from main bole stem sections in the greenhouse and from intact crowns, stumps, and hedged trees in situ and subsequently subjecting the new shoots to rooting trials. Mean shoot production was greater from forced stem sections of northern red oak (Quercus rubra L.) than from those of swamp white oak (Quercus bicolor Willd.) (14.6 and 4.6 shoots/m, respectively). Northern red oak stem sections exhibited a vertical gradient in the number of forced shoots; greater numbers originated from basal and juvenile sections of trees than from distal and mature sections. Rooting of swamp white oak shoots was low, 1.4% for forced shoots and none from hedged trees. Rooting of northern red oak was greater but variable, averaging 40.3% from greenhouse forced shoots and 0-35% from field-grown trees. Moreover, percent rooting was greatest for forced shoots originating from basal stem sections and declined with increasing distance from the tree base. The results suggest that ontogenetic maturation gradually increases, and rooting response decreases, along the bole of northern red oak trees.

A NEW SPECIES OF HOPLOCHAITOPHORUS FROM SWAMP WHITE OAK, WITH A KEY TO THE APTEROUS FORMS OF THE GENUS (HOMOPTERA: APHIDIDAE)

1972 ◽  
Vol 104 (10) ◽  
pp. 1539-1541
Author(s):  
F. W. Quednau
Keyword(s):  
New Species ◽  
White Oak ◽  
Quercus Bicolor ◽  
Swamp White Oak ◽  
A New Species

AbstractHoplochaitophorus spiniferus is described from swamp white oak, Quercus bicolor Willd. A key to the three known species of the genus is given.

Assessment and Orff Schulwerk Pedagogy

2019 ◽  
pp. 538-560
Author(s):  
Daniel Johnson
Keyword(s):  
Teacher Educators ◽  
Authentic Assessment ◽  
Research Literature ◽  
National Standards ◽  
International Adoptions ◽  
Practical Applications ◽  
Orff Schulwerk ◽  
Recent Developments ◽  
Based Instruction ◽  
Assessment Strategies

This chapter on assessing student learning and Orff Schulwerk examines the foundations of this approach, its focus on creativity, and practical applications of this pedagogy. By reviewing current research literature and international adoptions of the Schulwerk, the chapter focuses on three assessment-related challenges: a lack of clearly defined teaching practices, a de-emphasis of evaluation in the Orff process, and inherent challenges related to assessing creativity. An examination of professional resource documents and recent developments in national standards provides ways to address each of these assessment challenges in Orff-based instruction. A discussion of curricular levels offers more possibilities for enhancing authentic assessment strategies. Practical recommendations for Orff Schulwerk teachers to improve their assessment protocols and implications for teacher-educators conclude this chapter.

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