Finto Antony

Modeling the longitudinal variation in wood specific gravity of planted loblolly pine (Pinus taeda) in the United States.

Loblolly pine (Pinus taeda L.) is a major plantation species grown in the southern United States, producing wood having a multitude of uses including pulp and lumber production. Specific gravity (SG) is an important property used to measure the quality of wood produced, and it varies regionally and within the tree with height and radius. SG at different height levels was measured from 407 trees representing 135 plantations across the natural range of loblolly pine. A three-segment quadratic model and a semiparametric model were proposed to explain the vertical and regional variations in SG. Both models were in agreement that a stem can be divided into three segments based on the vertical variation in SG. Based on the fitted models, the mean trend in SG of trees from the southern Atlantic Coastal Plain and Gulf Coastal Plain was observed to be higher than in other physiographical regions (Upper Coastal Plain, Hilly Coastal Plain, northern Atlantic Coastal Plain, and Piedmont). Maps showing the regional var...

A Comparison of earlywood–latewood Demarcation Methods – A case study in Loblolly PINE

Demarcating the transition from earlywood (EW) to latewood (LW) is important for accurately estimating the width of both wood types within an annual ring, their respective densities and the proportion of LW within an annual ring. Different methods have been used to define the transition from EW to LW and include Mork’s index, the threshold density method and the inflection point method. In loblolly pine (Pinus taeda L.) a threshold value of 480 kg/m3 (basic density) has conventionally been used to demarcate EW from LW. In this study the three methods: a threshold density of 480 kg/m3, the inflection point method and Mork’s index were used to define the point at which EW transitioned to LW using annual rings for 20 loblolly pine breast height increment cores. Significant correlation was observed among the three methods in identifying the demarcation point. However, the results indicated that EW-LW demarcation points identified using the three methods in juvenile wood rings were different to mature wood rings; with the most pronounced differences being observed for Mork’s index.

Effect of midrotation fertilization on growth and specific gravity of loblolly pine

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 Car- olina. The study was laid out in a randomized complete-block design receiving four levels of nitrogen (N) fertilizer: unfer- tilized 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 in- creased radial growth. Fertilization rate of 336 kg/ha N significantly reduced 4 year average ring specific gravity and late- wood 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.

The effect of mid-rotation fertilization on the wood properties of loblolly pine (Pinus taeda).

Mid-rotation fertilization is a common practice in the management of loblolly pine (Pinus taeda L.) plantations, typically providing large improvements in growth. However, concerns exist about the quality of wood produced following fertilization. The objective of this study was to develop an understanding of wood property changes following fertilization. Wood samples from a study involving four levels of fertilization applied to a thinned mid-rotation loblolly pine plantation located on the lower coastal plain of North Carolina were sampled. The study was laid out in a randomized complete block design involving four blocks and four levels of nitrogen fertilizer: Control-000, 112, 224 and 336 kg/ha, along with 28 kg/ha of phosphorus with all treatments. Thirty-two trees were felled and disks were cut at five heights from each tree. Wood properties including modulus of elasticity, air-dry density and tracheid anatomical properties were measured for each of the three post-fertilization annual growth rings using near infrared (NIR) spectra obtained from the radial face of strips cut from the disks. An analysis of variance was conducted on three-year basal area weighted average stiffness, air-dry density, and tracheid anatomical properties. A decrease in stiffness, air-dry density, tracheid wall thickness, and an increase in tracheid radial diameter were observed for the heaviest fertilizer treatment (336 kg/ha) compared to the control and 112 kg/ha of nitrogen. Microfibril angle (MFA), cell tangential diameter, and tracheid perimeter showed little change. Wood properties of trees receiving fertilizer rates of 112 and 224 kg/ha were not significantly affected.

Effect of mid-rotation fertilization on stiffness and strength of loblolly pine wood

Trees sampled from a loblolly pine mid-rotation fertilization trial were used in this study. The study was laid out in a randomized complete block design with four levels of nitrogen fertilizer as treatments: control (000N), 112 (112N), 224 (224N), and 336 (336N) kg/ha of nitrogen, with each treatment replicated in 4 blocks. Two trees were destructively sampled from each plot giving a total of 32 trees. Bolts 0.6 m in length were collected from each tree (3 bolts per tree); with the midpoint of each bolt at heights of 2.4, 7.3 and 12.2 m from the base of the tree (each bolt represented the midpoint of standard 4.9 m saw logs). Static bending samples with dimensions 25 by 25 by 406 mm (radial, tangential and longitudinal dimensions respectively) were cut from the bolts that included the 25 mm of wood produced immediately following fertilization. Data on modulus of elasticity (MOE, stiffness) and modulus of rupture (MOR, strength) were collected from clear static bending samples. Based on the analysis of variance, no significant treatment effect was observed on MOE and MOR. However, MOE and MOR decreased in wood produced immediately after fertilization for trees which received the highest level of fertilization (336N). A decreasing trend in MOE and MOR with height was also present.

Relationships between Static Mechanical Properties and SilviScan Measured Wood Properties in Loblolly Pine

Abstract Relationships between static bending modulus of elasticity (MOE) and SilviScan (SS) properties (SilviScan MOE [MOESS], specific gravity, and microfibril angle) were explored. Seventy-three clearwood specimens (25 by 25 by 406 mm) were cut from thirty-two 33-year-old loblolly pine trees. Relationships were calculated between MOE and MOESS (R2 = 0.77); however, MOESS, calibrated using sonic resonance, averaged 25 percent higher than static MOE. Calibrating MOESS to static MOE instead of sonic resonance MOE resulted in similar prediction performance (R2 = 0.77), but more importantly approximately equal prediction values. The results demonstrate the importance of properly utilizing SilviScan information for predicting loblolly pine properties in static bending.