scholarly journals Effects of Stump Diameter on Sprout Number and Size for Three Oak Species in a Pennsylvania Clearcut

2009 ◽  
Vol 26 (3) ◽  
pp. 122-125 ◽  
Author(s):  
Benjamin A. Sands ◽  
Marc D. Abrams
Keyword(s):  
Maximum Height ◽  
White Oak ◽  
Diameter Class ◽  
Quercus Velutina ◽  
East Central ◽  
Central Pennsylvania ◽  
The Mean ◽  
Black Oak ◽  
Stump Sprouts ◽  
Stump Diameter

Abstract In a 2004 clearcut of a former even-aged oak (Quercus) forest, we examined the number and maximum height of stump sprouts for three oak species in east-central Pennsylvania. The greatest number of sprouts was produced by black oak (Quercus velutina) and chestnut oak (Q.montana) as compared with white oak (Q. alba). Logistic regression showed that diameter of stumps was a significant factor in determining the probability of sprouting for black oak, and an inverse relationship between stump diameter and the number of sprouts per stump was foundfor all three species. The number of white oak sprouts peaked in the 10‐20-cm diameter class and declined on larger stumps. The number of black oak sprouts peaked in the 20‐50-cm classes, and trees in the 70‐80-cm class produced the fewest sprouts. The mean annual growthof the tallest sprout on each stump was greater for black oak and chestnut oak than white oak.

Shoot elongation of black oak and white oak sprouts

1979 ◽  
Vol 9 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Paul S. Johnson
Keyword(s):  
Growing Season ◽  
Shoot Elongation ◽  
White Oak ◽  
Growing Seasons ◽  
Black Oak ◽  
Stump Diameter

Weekly events in shoot elongation were observed and measured for 43 black oak (Quercusvelutina Lam.) and 41 white oak (Q. alba L.) sprouts in their second growing season. In addition, total net shoot elongation (i.e., elongation minus current dieback) was measured at the ends of the first four growing seasons. Sprouts originated from stumps with diameters of 0.6 in. (1.5 cm) to 12 in. (30.5 cm). Average net elongation of both species reached a weekly maximum of 0.6 ft (18.3 cm) during the 3rd growth week (May 4–10). Although elongation among individual sprouts was extremely variable, most sprouts of both species flushed two or more times during the 17-week study period. Periods of individual flushes ranged from 1 to 3 weeks and most occurred during the first 13 growth weeks. Based on regression estimates, 2nd-year gross shoot elongation increased with increasing stump diameter up to 6 in. (15.2 cm); above this diameter shoot elongation decreased. Net 4-year elongation of both species also tended to increase with increasing stump diameter up to 6 in. There were no significant differences between species in 2nd-year gross elongation or in total 4-year net elongation.

Models for Estimating DBH from Stump Diameter for Southern Indiana Oaks

1990 ◽  
Vol 7 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Paul S. Johnson ◽  
Dale R. Weigel
Keyword(s):  
Nonlinear Regression ◽  
Red Oak ◽  
Northern Red Oak ◽  
White Oak ◽  
New Models ◽  
Species Groups ◽  
Diameter Outside Bark ◽  
Black Oak ◽  
Stump Diameter

Abstract Nonlinear regression estimates of DBH based on stump diameter outside bark 6 in. above ground are presented for northern red oak, and the white oak-scarlet oak and black oak-chestnut oak species groups in southern Indiana. Model estimates were compared to those from models developed for other regions. DBH estimates obtained from the new models and some previously reported models can be used to recontruct preharvest volume, value, and structure of harvested oak stands in southern Indiana. North. J. Appl. For. 7:79-81, June 1990.

An Investigation of Selected Factors that Influence Hardwood Wettability

Holzforschung ◽  
2001 ◽  
Vol 55 (5) ◽  
pp. 541-548 ◽  
Author(s):  
Todd F. Shupe ◽  
Chung Y. Hse ◽  
Wan H. Wang
Keyword(s):  
Contact Angle ◽  
Phenol Formaldehyde ◽  
Contact Angles ◽  
Red Oak ◽  
White Oak ◽  
Air Drying ◽  
Post Oak ◽  
The Mean ◽  
Species Pattern ◽  
Black Oak

Summary Wettability of sanded and non-sanded transverse and tangential sections of 22 southern hardwoods species was judged by measurement of contact angles using phenol formaldehyde resins. As expected, contact angle values on transverse sections were higher than those on tangential sections for both sanded and non-sanded surfaces. On sanded surfaces, hackberry had the highest mean contact angle (64.7°), and black oak had the lowest mean contact angle (50.1°). On non-sanded surfaces, winged elm had the highest mean contact angle (59.1°), and sweetgum had the lowest mean contact angle (45.9°). In addition, 4 of the 22 species (southern red oak, sweetgum, white oak, and post oak) were selected to investigate the effect of oven-drying, air-drying, and free-drying on wettability. The mean transverse contact was 2.1°–29.0° and 5.1°–31.5° higher than radial and tangential values, respectively. The contact angle pattern typically displayed for a given species and plane was generally oven-dry > air-dry > freeze-dry. The species pattern for most methods and planes was: sweetgum > white oak > post oak > southern red oak. White oak and post oak gave similar contact angle values.

Influence of weather at time of pollination on acorn production of Quercus alba and Quercus velutina

1999 ◽  
Vol 29 (12) ◽  
pp. 1817-1823 ◽  
Author(s):  
Robert A Cecich ◽  
Neal H Sullivan
Keyword(s):  
Pistillate Flower ◽  
Maximum Temperature ◽  
Quercus Alba ◽  
Negative Effects ◽  
White Oak ◽  
Weather Variables ◽  
Acorn Production ◽  
Quercus Velutina ◽  
Individual Trees ◽  
Black Oak

Pistillate flower development and acorn production were observed in small populations of white oak (Quercus alba L.) and black oak (Quercus velutina Lam.) in central Missouri from 1990 to 1997. There were significant year-year differences in the size of flower crops for both species and significant tree-tree differences in black oak. About 7% of the white oak flowers matured into acorns; most flowers aborted by early July, just after fertilization. About 12% of the black oak flowers matured into acorns, but some individual trees never or rarely produced a mature acorn. The number of fertilized flowers in white oak and black oak in early July was positively correlated with acorn production. Over all trees and years, the number of flowers and acorns were significantly correlated. Acorn production varied in relation to weather variables during the time of pollination. Simple regression models were good predictors of white oak acorn production but not of black oak acorn production. Maximum temperature and the number of days with hail had negative effects on acorn production. The number of days of rain during the pollination period was positively correlated with flower survival in black oak but not with white oak.

Stump diameter and DBH relationships for white oak and black oak in the Lower Peninsula of Michigan

1991 ◽  
Vol 21 (11) ◽  
pp. 1596-1600 ◽  
Author(s):  
Prabhat R. Ojasvi ◽  
Carl W. Ramm ◽  
Douglas O. Lantagne ◽  
Jeffrey Bruggink
Keyword(s):  
Geometric Model ◽  
Principal Component ◽  
Ground Level ◽  
Multivariate Model ◽  
Multivariate Models ◽  
White Oak ◽  
Geometric Models ◽  
Lower Peninsula ◽  
Black Oak ◽  
Stump Diameter

Principal component analysis of white oak (Quercusalba L.) and black oak (Quercusnigra L.) revealed different stem profiles across four ecological land units in the Lower Peninsula of Michigan. Multivariate linear regression and geometric models were developed to predict DBH from stump diameter for both species. For the multivariate model, the prediction variables were stump diameters at 15 and 30 cm above the ground level. The geometric model uses stump diameter at any height. Both the multivariate and geometric models can be used to predict DBH; however, the geometric models have the advantage of using fewer variables and being more flexible than the multivariate models.

Management of optic disc pit-associated maculopathy: A case series from a tertiary referral center

2021 ◽  
pp. 112067212110237
Author(s):  
Ilkay Kilic Muftuoglu ◽  
Ecem Onder Tokuc ◽  
V Levent Karabas
Keyword(s):  
Optic Disc ◽  
Case Series ◽  
Internal Limiting Membrane ◽  
Maximum Height ◽  
Optic Disc Pit ◽  
Tertiary Referral Center ◽  
Number Of Patients ◽  
The Mean ◽  
Foveal Center

Purpose: To report outcomes of pars plana vitrectomy (PPV) combined with internal limiting membrane (ILM) stuffing technique in patients with optic disc pit associated maculopathy (ODP-M). Methods: Data including best-corrected visual acuity (BCVA), central macular thickness (CMT), foveal center point thickness (FCP), and maximum height of fluid (max_fluid) (intraretinal or subretinal) were collected from the medical records of the patients. Results: Six eyes of six patients with a mean age of 28.0 ± 17.68 years (range: 9–53 year) underwent PPV + ILM plug surgery. The mean follow-up duration was 25.62 ± 26.11 months (range: 11.80–78.00 month) duration. The mean BCVA increased from 1.25 ± 1.04 logMAR (20/355, Snellen equivalent) to 0.86 ± 1.09 logMAR (20/144, Snellen equivalent) at last follow-up ( p = 0.043). Compared to baseline, CMT, FCP, and max_fluid significantly decreased at all visits after the surgery ( p < 0.05 for all visits). At last follow-up, 66.6% of the eyes (four eyes) showed complete resolution of fluid at a mean of 5.25 ± 4.99 months (range: 1–12 months) after the surgery. Conclusion: PPV with ILM plug seemed to be an effective surgical technique in ODP-M. Studies with longer follow-up and higher number of patients are needed to confirm our results.

Pituitary dimensions and volume measurements in pregnancy and post partum

1998 ◽  
Vol 39 (1) ◽  
pp. 64-69 ◽  
Author(s):  
H. Dinç ◽  
F. Esen ◽  
A. Demirci ◽  
A. Sari ◽  
H. Resit Gümele
Keyword(s):  
Pituitary Gland ◽  
Matched Control ◽  
Post Partum ◽  
Three Dimensions ◽  
Maximum Height ◽  
Third Trimester ◽  
Normal Pituitary Gland ◽  
Volume Measurements ◽  
Length Width ◽  
The Mean

Purpose: Our purpose was to clarify and further characterize the changes in height, length, width, volume, and shape in the normal pituitary gland and in width in the infundibulum during pregnancy and the first 6 months post partum. Material and Methods: Cranial MR imaging was performed in 78 women who were pregnant in the second or third trimester or who were post partum, and in 18 age-matched control subjects who were not pregnant. Volume measurements were performed in 2 ways; volume 1=1/2xheightxlengthxwidth; and volume 2=area (measured by trackball)xslice thickness Results: Gland volume, height, width, length, and convexity, and infundibular width increased during pregnancy. the highest values were seen during the 3 days immediately post partum. When compared with volunteers, volumes 1 and 2 showed the largest increase (120%) among the parameters. Gland height showed the best correlation (r=0.94, p>0.00001) with gestational age. the mean height of the gland was 8.76 mm in the third trimester. None of the pregnant women had a gland height of above 10 mm during pregnancy. Only 2 subjects had gland heights of 10.04 and 10.2 mm during the 0–3 days post partum. After this first post-partum period of 3 days, the gland size, shape, and volume and the infundibular width returned to normal within 6 months Conclusion: the pituitary gland enlarges in three dimensions throughout pregnancy. During pregnancy, the volume of the gland shows the highest percentage of increase compared to its length, height, and width. the maximum height of the gland does not exceed 10 mm during pregnancy but it may exceed 10 mm during the 3 days immediately post partum.

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