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

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.

2009 ◽  
Vol 26 (3) ◽  
pp. 122-125 ◽  
Author(s):  
Benjamin A. Sands ◽  
Marc D. Abrams

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.


1979 ◽  
Vol 9 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Paul S. Johnson

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.


1990 ◽  
Vol 7 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Paul S. Johnson ◽  
Dale R. Weigel

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.


2019 ◽  
pp. 40-47
Author(s):  
E. A. Mironchik

The article discusses the method of solving the task 18 on the Unified State Examination in Informatics (Russian EGE). The main idea of the method is to write the conditions of the problem utilizing the language of formal logic, using elementary predicates. According to the laws of logic the resulting complex logical expression would be transformed into an expression, according to which a geometric model is supposed to be constructed which allows to obtain an answer. The described algorithm does allow high complexity problem to be converted into a simple one.


2016 ◽  
Author(s):  
Loredana G. Suciu ◽  
Robert J. Griffin ◽  
Caroline A. Masiello

Abstract. Ozone (O3) in the lower troposphere is harmful to people and plants, particularly during summer, when photochemistry is the most active and higher temperatures favor local chemistry. Because of its dependence on the volatile organic compounds (VOCs) to nitrogen oxides (NOx) ratio, ground-level O3 is difficult to control locally, where many sources of these precursors contribute to its mixing ratio. In addition to local emissions, chemistry and transport, larger-scale factors also contribute to local O3 and NOx. These additional contributions (often referred to as "regional background") are not well quantified within the Houston-Galveston-Brazoria (HGB) region, impeding more efficient controls on precursor emissions to achieve compliance with the National Ambient Air Quality Standards for O3. In this study, we estimate regional background O3 and NOx in the HGB region and quantify their decadal-scale trends. We use four different approaches based on principal component analysis (PCA) to quantify background O3 and NOx. Three of these approaches consist of independent PCA on both O3 and NOx for both 1-h and 8-h levels to compare our results with previous studies and to highlight the effect of both temporal and spatial scales. In the fourth approach, we co-varied O3, NOx and meteorology. Our results show that the estimation of regional background O3 has less inherent uncertainty when it was constrained by NOx and meteorology, yielding a statistically significant temporal trend of −0.69 ± 0.27 ppb y−1. Likewise, the estimation of regional background NOx trend constrained by O3 and meteorology was −0.04 ± 0.02 ppb y−1. Our best estimates of 17-y average of season-scale background O3 and NOx were 46.72 ± 2.08 ppb and 6.80 ± 0.13 ppb, respectively. Regional background O3 and NOx both have declined over time in the HGB region. This decline is likely caused by a combination of state of Texas controls on precursor emissions since 2007 and the increase in frequency of flow from the Gulf of Mexico over the same time period.


The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 377-388 ◽  
Author(s):  
Jeffrey E. Moore ◽  
Robert K. Swihart

Abstract We assessed dietary preference of 14 captive Blue Jays (Cyanocitta cristata) for different food types under different conditions of availability. In four separate feeding trials, we provisioned jays with the following: Trial 1, two nuts each of white oak (Quercus alba), pin oak (Q. palustris), black oak (Q. velutina), northern red oak (Q. rubra), and shagbark hickory (Carya ovata); Trial 2, two small and two large red oak acorns; Trial 3, two germinating and two nongerminating white oak acorns; and Trial 4, one large red oak acorn, one large white oak acorn, and one shagbark hickory nut. We used discrete choice models to describe selection under conditions of changing choice sets. Blue Jays displayed a clear preference for pin oak and strong avoidance of red oak acorns when alternative foods were available. White oak and black oak acorns were selected intermediately. Shagbark hickory nuts were never used. Correlation coefficients suggested that preference was inversely related to seed size and the proportion of seed consisting of hard seed coat. In the absence of alternative food items, small red oak acorns were readily taken, whereas large red oak acorns were mostly avoided but still used by some birds. These results highlight the importance of considering food availability when making conclusions about preference, and lend support to the hypothesis that Blue Jays can be important dispersers of even less-preferred oak species. We discuss the potential as well as the limitations for Blue Jays to act as seed dispersers, with respect to postglacial range expansion of fagaceous tree species, and in the context of present-day dispersal in regions where forests are highly fragmented.


Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 224-224 ◽  
Author(s):  
Q. Huang

Bacterial leaf scorch caused by Xylella fastidiosa has been reported in 17 species of oak including bur, pin, red, scarlet, shingle, and white oaks (3). In September 2002, a leaf scorch symptom characterized by marginal necrosis of leaves bordered by a darker brown band was observed in a mature black oak (Quercus velutina Lam.) at the U.S. National Arboretum in Washington, D.C. The leaf petiole of the black oak was processed in general extraction buffer (Agdia, Inc., Elkhart, IN) contained in a FastDNA lysing matrix tube using the FastPrep FP120 instrument (Qbiogene, Inc., Carlsbad, CA) (1). The leaf petiole extract reacted with an antiserum specific for X. fastidiosa (Agadia, Inc.) in an enzyme-linked immunosorbent assay (ELISA). A slow-growing bacterium was cultured from leaf petioles of the affected black oak tree by soaking the surface-sterilized, finely cut leaf petioles in sterile water for 30 min, followed by spreading the bacterial suspension on periwinkle wilt plates (1). When the cultured bacterium was subjected to polymerase chain reaction (PCR) with primers specific for X. fastidiosa (2), a 472-bp PCR product was detected. The PCR product was confirmed to be the predicted X. fastidiosa product by sequencing and sequence comparison with the reported genomic sequence of X. fastidiosa. ELISA and bacterial isolation from leaf petioles of a nearby symptomless white oak (Q. alba L.) tree were negative. To our knowledge, this is the first report of X. fastidiosa associated with leaf scorch in black oak in the United States, expanding the host range of the bacterium in economically important landscape tree species. References: (1) Q. Huang and J. L. Sherald. Curr. Microbiol. 48:73, 2004. (2) M. R. Pooler and J. S. Hartung. Curr. Microbiol. 31:377, 1995. (3) J. L. Sherald. Xylella fastidiosa, A bacterial pathogen of landscape trees. Page 191 in: Shade Tree Wilt Diseases, C. L. Ash, ed. The American Phytopathological Society, 2001.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-23 ◽  
Author(s):  
Mauro Castelli ◽  
Fabiana Martins Clemente ◽  
Aleš Popovič ◽  
Sara Silva ◽  
Leonardo Vanneschi

Predicting air quality is a complex task due to the dynamic nature, volatility, and high variability in time and space of pollutants and particulates. At the same time, being able to model, predict, and monitor air quality is becoming more and more relevant, especially in urban areas, due to the observed critical impact of air pollution on citizens’ health and the environment. In this paper, we employ a popular machine learning method, support vector regression (SVR), to forecast pollutant and particulate levels and to predict the air quality index (AQI). Among the various tested alternatives, radial basis function (RBF) was the type of kernel that allowed SVR to obtain the most accurate predictions. Using the whole set of available variables revealed a more successful strategy than selecting features using principal component analysis. The presented results demonstrate that SVR with RBF kernel allows us to accurately predict hourly pollutant concentrations, like carbon monoxide, sulfur dioxide, nitrogen dioxide, ground-level ozone, and particulate matter 2.5, as well as the hourly AQI for the state of California. Classification into six AQI categories defined by the US Environmental Protection Agency was performed with an accuracy of 94.1% on unseen validation data.


2006 ◽  
Vol 84 (8) ◽  
pp. 1233-1248 ◽  
Author(s):  
Christopher T. Yarnes ◽  
William J. Boecklen ◽  
Kati Tuominen ◽  
Juha-Pekka Salminen

Interspecific variation in phenolic metabolism across plant species has been correlated to numerous ecological factors, yet generalities concerning the ecological role(s) of phenolics remain elusive. Moreover, studies of allometric variation (absolute and relative concentration) in phenolic metabolism are rare despite the importance of each to ecological interactions. In this study, we characterize individual phenolics in a group of 12 oak species from the Chihuahuan Desert and examine interspecific variation in the absolute and relative concentrations of phenolics using size and shape analysis. Size and shape analysis was able to successfully identify those compounds that contribute most to the interspecific allometric variation in phenolics and classify the oak species on the basis of phenolic metabolism. White versus black oak subgenera were found to be most different in their phenolic composition, where the two black oak species contained fewer and less diverse phenolics. Within the 10 white oak species, a predominantly eastern white oak, Quercus muhlenbergii Engelmann, was found to vary significantly from the more widespread white oaks of the Chihuahuan Desert. We also report the occurrence of complex tannins in oaks of North America for the first time, update proposed pathways of ellagitannin biosynthesis in oaks, and discuss the applicability of size and shape analysis to ecological studies of phenolics.


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