Quercus macrocarpa: Kenny, L. & Wenzell , K.

2015 ◽  
Author(s):  
Keyword(s):  
Quercus Macrocarpa

scholarly journals Measuring the Contribution of Leaves to the Structural Complexity of Urban Tree Crowns with Terrestrial Laser Scanning

2021 ◽  
Vol 13 (14) ◽  
pp. 2773
Author(s):  
Georgios Arseniou ◽  
David W. MacFarlane ◽  
Dominik Seidel
Keyword(s):  
Laser Scanning ◽  
Structural Complexity ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Urban Trees ◽  
Box Dimension ◽  
State University ◽  
Leaf Removal ◽  
Quercus Macrocarpa ◽  
Methodological Considerations

Trees have a fractal-like branching architecture that determines their structural complexity. We used terrestrial laser scanning technology to study the role of foliage in the structural complexity of urban trees. Forty-five trees of three deciduous species, Gleditsia triacanthos, Quercus macrocarpa, Metasequoia glyptostroboides, were sampled on the Michigan State University campus. We studied their structural complexity by calculating the box-dimension (Db) metric from point clouds generated for the trees using terrestrial laser scanning, during the leaf-on and -off conditions. Furthermore, we artificially defoliated the leaf-on point clouds by applying an algorithm that separates the foliage from the woody material of the trees, and then recalculated the Db metric. The Db of the leaf-on tree point clouds was significantly greater than the Db of the leaf-off point clouds across all species. Additionally, the leaf removal algorithm introduced bias to the estimation of the leaf-removed Db of the G. triacanthos and M. glyptostroboides trees. The index capturing the contribution of leaves to the structural complexity of the study trees (the ratio of the Db of the leaf-on point clouds divided by the Db of the leaf-off point clouds minus one), was negatively correlated with branch surface area and different metrics of the length of paths through the branch network of the trees, indicating that the contribution of leaves decreases as branch network complexity increases. Underestimation of the Db of the G. triacanthos trees, after the artificial leaf removal, was related to maximum branch order. These results enhance our understanding of tree structural complexity by disentangling the contribution of leaves from that of the woody structures. The study also highlighted important methodological considerations for studying tree structure, with and without leaves, from laser-derived point clouds.

Absorption, Translocation, and Degradation of Tebuthiuron and Hexazinone in Woody Species

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 739-743 ◽  
Author(s):  
Wayne K. McNeil ◽  
Jimmy F. Stritzke ◽  
Eddie Basler
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Woody Species ◽  
Black Walnut ◽  
The Other ◽  
Juniperus Virginiana ◽  
Eastern Redcedar ◽  
Quercus Macrocarpa ◽  
Root Absorption ◽  
Bur Oak

Seedlings of winged elm (Ulmus dataMichx.), bur oak (Quercus macrocarpaMichx.), black walnut (Juglans nigraL.), eastern redcedar (Juniperus virginianaL.), and loblolly pine (Pinus taedaL.) were treated in nutrient solution with ring-labeled14C-tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} or14C-hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione]. Four hours later,14C was detected in all sections of winged elm treated with14C-tebuthiuron and14C-hexazinone. Root absorption of the tebuthiuron label by the other species occurred in the order: loblolly pine > bur oak > black walnut = eastern redcedar. The sequence of14C-hexazinone absorption was: loblolly pine > black walnut ≥ bur oak = eastern redcedar. Foliar accumulation of the tebuthiuron label occurred in the order: bur oak > loblolly pine > eastern redcedar = black walnut, whereas the sequence with hexazinone was loblolly pine > bur oak > black walnut = eastern redcedar. The presence of the three metabolites of hexazinone in loblolly pine suggests that it may be resistant to hexazinone as a result of its ability to degrade hexazinone rather than its ability to limit uptake.

scholarly journals Adventitious Root Formation in Stem Cuttings of Quercus bicolor and Quercus macrocarpa and Its Relationship to Stem Anatomy

2008 ◽  
Vol 133 (4) ◽  
pp. 479-486 ◽  
Author(s):  
J. Naalamle Amissah ◽  
Dominick J. Paolillo ◽  
Nina Bassuk
Keyword(s):  
Secondary Growth ◽  
Adventitious Root Formation ◽  
Fiber Bundles ◽  
Vascular Bundles ◽  
Stem Cuttings ◽  
Root Primordia ◽  
Stem Anatomy ◽  
Indole Butyric Acid ◽  
Quercus Macrocarpa ◽  
Quercus Bicolor

This study investigated the relationship of stem anatomy to differences in rooting ability between Quercus bicolor Wild. and Quercus macrocarpa Michx. cuttings. Quercus bicolor cuttings were found to have a significantly greater proportion of parenchymatous gaps in the sclerenchyma sheath over a 9-week period compared with Q. macrocarpa cuttings. In Q. macrocarpa, the percentage gap was generally low, coinciding with the low percentage rooting observed in this species. Percentage rooting correlated well (r2 = 0.75) with the percentage parenchymatous gap in the perivascular region of Q. bicolor cuttings. The problems with accepting this relationship as causal are stated in the discussion. Untreated cuttings showed normal stem organization: a dermal tissue system that included the initial stages of phellem formation, a cortex, and a ring of closely arranged vascular bundles in early stages of secondary growth. The locations of the five distinct lobes of the pith were coordinated with the locations of root primordia. Callus growth was first detected in the cortex (i.e., external to the fiber bundles), followed by proliferation within the phloem, opposite the lobes of the pith, 8 to 12 days after cuttings were treated with indole butyric acid (6000 mg·L−1 dissolved in 50% v/v ethanol in water). By 14 to 16 days, root primordia had developed within the proliferative tissue in the secondary phloem. In both species, root primordia penetrated parenchymatous gaps in the fiber sheath directly, the fiber bundles being displaced laterally as the roots increased in size.

scholarly journals Spectral differentiation of oak wilt from foliar fungal disease and drought is correlated with physiological changes

2020 ◽  
Vol 40 (3) ◽  
pp. 377-390 ◽  
Author(s):  
Beth Fallon ◽  
Anna Yang ◽  
Cathleen Lapadat ◽  
Isabella Armour ◽  
Jennifer Juzwik ◽  
...  
Keyword(s):  
Water Status ◽  
Hyperspectral Data ◽  
Oak Wilt ◽  
Quercus Macrocarpa ◽  
Stress Symptoms ◽  
Spectral Models ◽  
Bur Oak ◽  
Quercus Ellipsoidalis ◽  
Sources Of Infection ◽  
Tree Stress

Abstract Hyperspectral reflectance tools have been used to detect multiple pathogens in agricultural settings and single sources of infection or broad declines in forest stands. However, differentiation of any one disease from other sources of tree stress is integral for stand and landscape-level applications in mixed species systems. We tested the ability of spectral models to differentiate oak wilt, a fatal disease in oaks caused by Bretziella fagacearum ``Bretz'', from among other mechanisms of decline. We subjected greenhouse-grown oak seedlings (Quercus ellipsoidalis ``E.J. Hill'' and Quercus macrocarpa ``Michx.'') to chronic drought or inoculation with the oak wilt fungus or bur oak blight fungus (Tubakia iowensis ``T.C. Harr. & D. McNew''). We measured leaf and canopy spectroscopic reflectance (400–2400 nm) and instantaneous photosynthetic and stomatal conductance rates, then used partial least-squares discriminant analysis to predict treatment from hyperspectral data. We detected oak wilt before symptom appearance, and classified the disease with high accuracy in symptomatic leaves. Classification accuracy from spectra increased with declines in photosynthetic function in oak wilt-inoculated plants. Wavelengths diagnostic of oak wilt were only found in non-visible spectral regions and are associated with water status, non-structural carbohydrates and photosynthetic mechanisms. We show that hyperspectral models can differentiate oak wilt from other causes of tree decline and that detection is correlated with biological mechanisms of oak wilt infection and disease progression. We also show that within the canopy, symptom heterogeneity can reduce detection, but that symptomatic leaves and tree canopies are suitable for highly accurate diagnosis. Remote application of hyperspectral tools can be used for specific detection of disease across a multi-species forest stand exhibiting multiple stress symptoms.

A Description of the Previously Unknown Male of Cyrtolobus griseus Van Duzee

1951 ◽  
Vol 83 (4) ◽  
pp. 106-106
Author(s):  
Clifford J. Dennis
Keyword(s):  
Quercus Macrocarpa ◽  
University Of Wisconsin ◽  
Bur Oak ◽  
The University ◽  
Unknown Male

Apparently, the male of Cyrtolobus griseus Van Duzee (Stud. N.A. Memb. 90.16, 1908) has never been described. The following is a description of a male which is here designated the allotype. This specimen was collected in the University of Wisconsin Arboretum, Madison, July 21, 1950 from bur oak (Quercus macrocarpa Michx.). The allotype is in the author's collection.

The association of two invasive shrubs, common buckthorn (Rhamnus cathartica) and Tartarian honeysuckle (Lonicera tatarica), with oak communities in the midwestern United States

2011 ◽  
Vol 41 (10) ◽  
pp. 1981-1992 ◽  
Author(s):  
Lisa A. Schulte ◽  
Erik C. Mottl ◽  
Brian J. Palik
Keyword(s):  
United States ◽  
Soil Nutrient ◽  
Oak Forests ◽  
Quercus Alba ◽  
Forest Edges ◽  
Rhamnus Cathartica ◽  
White Oak ◽  
Midwestern United States ◽  
Quercus Macrocarpa ◽  
Bur Oak

Oak forests throughout North America are declining due to changes in disturbance regimes that have led to increased competition from other tree and shrub species. We evaluated associations between oak regeneration, the occurrence of two common invasive shrubs (common buckthorn ( Rhamnus cathartica L.) and Tartarian honeysuckle ( Lonicera tatarica L.)), and forest edges in oak forests in a portion of the midwestern United States where bur ( Quercus macrocarpa Michx.), red ( Quercus rubra L.), and white oak ( Quercus alba L.) were historically dominant. We found poor recruitment of oaks in comparison to other, more shade-tolerant tree species. Results further revealed a strong stand-scale association between bur oak, open canopy conditions, high soil nutrient levels, and the presence of common buckthorn and Tartarian honeysuckle; these same site characteristics were disassociated with red and white oak. Within red and white oak stands, however, the presence of the invasive shrubs was more pronounced near forest edges. While oak recruitment is hampered throughout stands, our research suggests that predominant constraints may vary based on soil and light gradients found along forest edges.

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