Identification of representative sampling heights for specific gravity and moisture content in plantation-grown loblolly pine (Pinus taeda)

2012 ◽  
Vol 42 (3) ◽  
pp. 574-584 ◽  
Author(s):  
Finto Antony ◽  
Laurence R. Schimleck ◽  
Richard F. Daniels

Conventionally, increment cores collected at breast height (1.4 m) have been used to measure wood properties of standing loblolly pine (Pinus taeda L.) trees. This height has been used because of the ease of sampling and cost involved in extracting the cores. In this study, the efficacy of a breast-height core to represent whole-tree specific gravity (SG) and moisture content (MC) was examined. The sampling height that best represents whole-tree SG and MC was identified using the correlation between volume-weighted whole-tree SG and MC with SG and MC measurements collected at different heights within a tree. We found a high correlation between observed whole-disk SG and MC with volume-weighted whole-tree SG and MC at most sampling heights. The strength of the correlation followed a skewed parabolic curve form for both wood properties. The strongest correlations were observed between 4.6 and 6.1 m, with marginally lower correlations at the base of the tree, and the weakest correlations were observed towards the tip of the tree. In addition, it was found that the number of stands and trees that need to be sampled to achieve a certain accuracy in overall mean whole-tree SG and MC was greater if breast height was used as a sampling height compared with the most representative sampling heights identified (4.6 m for SG and 6.1 m for MC).

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  

2009 ◽  
Vol 39 (5) ◽  
pp. 928-935 ◽  
Author(s):  
Finto Antony ◽  
Lewis Jordan ◽  
Richard F. Daniels ◽  
Laurence R. Schimleck ◽  
Alexander Clark ◽  
...  

Wood properties and growth were measured on breast-height cores and on disks collected at different heights from a thinned and fertilized midrotation loblolly pine ( Pinus taeda L.) plantation in the lower Coastal Plain of North Carolina. The study was laid out in a randomized complete-block design receiving four levels of nitrogen (N) fertilizer: unfertilized control and 112, 224, and 336 kg/ha plus 28 kg/ha of phosphorus with each treatment. The effect of fertilization was analyzed for the whole-disk and for a 4 year average following fertilization on data collected from breast-height cores and from disks. The fertilization treatments did not significantly affect whole-disk wood properties but significantly increased radial growth. Fertilization rate of 336 kg/ha N significantly reduced 4 year average ring specific gravity and latewood specific gravity. Wood properties of trees that received 112 and 224 kg/ha N were not affected following treatment. There was no height related trend in wood property changes due to fertilization. Fertilization significantly increased ring basal area and earlywood basal area. In summary, there was a decline in wood properties and an increase in basal area growth immediately after fertilization; both depended on the rate of fertilizer applied irrespective of height.


2005 ◽  
Vol 35 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P D Jones ◽  
L R Schimleck ◽  
G F Peter ◽  
R F Daniels ◽  
A Clark III

Preliminary studies based on small sample sets show that near infrared (NIR) spectroscopy has the potential for rapidly estimating many important wood properties. However, if NIR is to be used operationally, then calibrations using several hundred samples from a wide variety of growing conditions need to be developed and their performance tested on samples from new populations. In this study, 120 Pinus taeda L. (loblolly pine) radial strips (cut from increment cores) representing 15 different sites from three physiographic regions in Georgia (USA) were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were collected in 10-mm increments from the radial longitudinal surface of each strip and split into calibration (nine sites, 729 spectra) and prediction sets (six sites, 225 spectra). Calibrations were developed using untreated and mathematically treated (first and second derivative and multiplicative scatter correction) spectra. Strong correlations were obtained for all properties, the strongest R2 values being 0.83 (density), 0.90 (MFA), and 0.93 (stiffness). When applied to the test set, good relationships were obtained (Rp2 ranged from 0.80 to 0.90), but the accuracy of predictions varied depending on math treatment. The addition of a small number of cores from the prediction set (one core per new site) to the calibration set improved the accuracy of predictions and importantly minimized the differences obtained with the various math treatments. These results suggest that density, MFA, and stiffness can be estimated by NIR with sufficient accuracy to be used in operational settings.


2002 ◽  
Vol 104 (2) ◽  
pp. 214-222 ◽  
Author(s):  
M. M. Sewell ◽  
M. F. Davis ◽  
G. A. Tuskan ◽  
N. C. Wheeler ◽  
C. C. Elam ◽  
...  

2003 ◽  
Vol 33 (12) ◽  
pp. 2297-2305 ◽  
Author(s):  
L R Schimleck ◽  
C Mora ◽  
R F Daniels

The application of near infrared (NIR) spectroscopy to the green wood of radial samples (simulated increment cores) and the development of calibrations for the prediction of wood properties are described. Twenty Pinus taeda L. (loblolly pine) radial strips were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were obtained in 10-mm steps from the radial longitudinal and transverse faces of each sample and used to develop calibrations for each property. NIR spectra were collected when the wood was green (moisture content ranged from approximately 100% to 154%) and dried to approximately 7% moisture content. Relationships between measured and NIR estimates for green wood were good; coefficients of determination (R2) ranged from 0.79 (MFA) to 0.85 (air-dry density). Differences between calibrations developed using the radial longitudinal and transverse faces were small. Calibrations were tested on an independent set. Predictive errors were relatively large for some green samples and relationships were moderate; R2p ranged from 0.67 (MFA) to 0.81 (stiffness). Dry wood calibrations demonstrated strong predictive relationships with R2p ranging from 0.87 (air-dry density) to 0.95 (stiffness). NIR spectroscopy has the potential to predict the air-dry density, MFA, and stiffness of 10-mm sections of green P. taeda wood samples.


2011 ◽  
Vol 35 (3) ◽  
pp. 142-147 ◽  
Author(s):  
Finto Antony ◽  
Laurence R. Schimleck ◽  
Richard F. Daniels ◽  
Alexander Clark

Abstract Growth and wood properties were measured on breast height cores collected from two stands, New Bern and Bertie, located in the lower Coastal Plain of North Carolina. The New Bern site was thinned before fertilizer application, and the Bertie site was not. The study was laid out in a randomized complete block design with each treatment replicated in four blocks at New Bern and two blocks at Bertie. The treatments were different levels of nitrogen fertilization: control (no nitrogen) and 112, 224, and 336 kg/ha. In addition, 28 kg/ha of phosphorus was included with each treatment. The objective of this study was to examine the response in growth and wood properties to midrotation fertilization in a thinned versus an unthinned stand. A significant decrease in latewood specific gravity was observed following nitrogen fertilization in the thinned stand but not in the unthinned stand. Whole ring width, latewood width, and earlywood width significantly increased following nitrogen fertilization at New Bern but not at Bertie. Whole ring specific gravity, earlywood specific gravity, latewood percentage, and earlywood:latewood ratio did not show any change due to fertilization in either stand. Responses in both growth and wood characteristics lasted for 2–3 years following fertilization and depended on the amount of fertilizer applied and whether or not the site was thinned. The response to nitrogen application was significant for the thinned stand only.


2000 ◽  
Vol 101 (8) ◽  
pp. 1273-1281 ◽  
Author(s):  
M. M. Sewell ◽  
D. L. Bassoni ◽  
R. A. Megraw ◽  
N. C. Wheeler ◽  
D. B. Neale

1988 ◽  
Vol 12 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Bruce R. Zutter ◽  
Patrick J. Minogue ◽  
Dean H. Gjerstad

Abstract Four growing seasons after aerial applications of glyphosate at 1.0, 1.5 or 2.0 lb ai/ac in a three-year-old loblolly pine (Pinus taeda L.) plantation in late summer, diameter at breast height (dbh) and total height of pines were greater on treated compared to untreated areas. Pines on treated plots averaged 2.5 in. dbh and 15.2 ft in height while pines on untreated plots averaged 1.9 in. dbh and 13.5 ft in height. Height growth curves of treated pines through four growing seasons following treatment. In general, reduction in hardwood density and pine response each increased with increasing glyphosate rate. Relative composition of red maple in the stand increased two years after treatment for all rates of glyphosate, but did not change in the plots without treatment. South. J. Appl. For. 12(1):54-58.


2009 ◽  
Vol 33 (2) ◽  
pp. 58-61 ◽  
Author(s):  
Quang V. Cao

Abstract Recent advances in laser technology help make possible accurate and affordable measurements of upper-stem diameters. These measurements can be used to calibrate results from a taper equation to improve the accuracy of diameter predictions along the tree bole. Felled-tree data from a loblolly pine (Pinus taeda L.) plantation were used to evaluate two methods for calibrating outputs from a segmented taper equation with parameters either obtained from the data in this study or originally published by <xref ref-type="bibr" rid="B5-2124">Max and Burkhart (1976</xref>, Segmented polynomial regression applied to taper equations, For. Sci. 22:283–289). For outside-bark diameters, although a simple calibration for dbh gave desirable results, a better calibration involving both dbh and an upper-stem diameter provided significant improvements in predicting tree taper. Results varied depending on where the diameter was measured, with optimum gains obtained when the upper-stem diameter was measured at the midpoint between breast height and the tree tip. For inside-bark diameters, the calibration for inside-bark dbh actually produced inferior predictions, whereas the calibration based on both dbh and an upper-stem diameter offered only modest improvements over the unadjusted predictions.


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