Regional variation in wood modulus of elasticity (stiffness) and modulus of rupture (strength) of planted loblolly pine in the United States

Modulus of elasticity (MOE), modulus of rupture (MOR), and specific gravity (SG) are important properties for determining the end-use and value of a piece of lumber. This study addressed the variation in MOE, MOR, and SG with physiographic region, tree height, and wood type. Properties were measured from two static bending samples (dimensions 25.4 mm × 25.4 mm × 406.4 mm) representing each wood type (corewood and outerwood) at heights 2.4, 7.3, and 12.2 m from three trees sampled from 135 loblolly pine ( Pinus taeda L.) stands distributed across the natural range of the species. An analysis of variance was conducted to detect the effect of physiographpic region, height, and wood type on each property. Significant regional variation was observed for MOE, MOR, and SG for both wood types with high values in the Gulf and South Atlantic Coastal Plains compared with other regions. A significant height-related trend in MOE, MOR, and SG within a tree was identified; MOE and MOR increased in corewood and decreased in outerwood with height. Maps showing regional variation in MOE and MOR at different heights by wood type were produced and showed significant variation for both properties.

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Crown efficiency in a loblolly pine (Pinus taeda) spacing experiment

Canadian Journal of Forest Research ◽

10.1139/x98-115 ◽

1998 ◽

Vol 28 (9) ◽

pp. 1344-1351 ◽

Cited By ~ 12

Author(s):

Hubert Sterba ◽

Ralph L Amateis

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Basal Area ◽

Tree Height ◽

Projection Area ◽

Individual Tree ◽

Dominant Height ◽

Crown Projection Area ◽

Pinus Taeda L ◽

Crown Closure

Crown efficiency was first defined by Assmann (1961. Waldertragskunde. BLV, München) as individual tree volume increment per unit of crown projection area. He hypothesized that within a given crown class, smaller crowns are more efficient because their ratio between crown surface and horizontal crown projection is higher. Data from a loblolly pine (Pinus taeda L.) spacing experiment were used to test if this hypothesis also holds in young loblolly pine stands and, if so, to determine if it explains the increment differences between spacings in the spacing experiment. Using individual tree height relative to plot dominant height to describe crown class, within-plot regression showed that crown efficiency decreased with crown size for trees below dominant height. This relationship was much less pronounced than indicated from Assmann's examples, although the crown surface to crown projection ratio behaved in the same way as Assmann had hypothesized. Crown efficiency as well as the crown surface to crown projection area ratio decreased with increasing density. Basal area increment per hectare increased until total crown closure approached 130% and then stayed constant. This major impact of total crown coverage brings into question the usefullness of crown efficiency as an indicator for unit area growth.

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Effect of Silvicultural Practice and Wood Type on Loblolly Pine Particleboard and Medium Density Fiberboard Properties

Holzforschung ◽

10.1515/hf.1999.036 ◽

1999 ◽

Vol 53 (2) ◽

pp. 215-222 ◽

Cited By ~ 3

Author(s):

Todd F. Shupe ◽

Chung Y. Hse ◽

Elvin T. Choong ◽

Leslie H. Groom

Keyword(s):

Physical Properties ◽

Pinus Taeda ◽

Loblolly Pine ◽

Medium Density Fiberboard ◽

Thickness Swell ◽

Modulus Of Rupture ◽

Wood Type ◽

Mechanical And Physical Properties ◽

Silvicultural Practice ◽

Strategy I

Summary The objective of this study was to determine the effect of five different silvicultural strategies and wood type on mechanical and physical properties of loblolly pine (Pinus taeda L.) particleboard and fiberboard. The furnish was prepared in an unconventional manner from innerwood and outerwood veneer for each stand. Modulus of rupture (MOR) differences between the stands were insignificant for particleboard. Some significant modulus of elastisity (MOE) differences existed between the stands for particleboard and fiberboard. Differences between the wood types were minimal for each stand. Innerwood yielded higher mean MOR, MOE, and internal bond (IB) values than outerwood for most of the stands. The differences between the stand and wood types for 2 and 24 h thickness swell and 2 and 24h water adsorption were very minimal. This research has shown that innerwood can produce particleboard and fiberboard panels with very comparable mechanical and physical properties to outerwood. The effect of the silvicultural strategy (i. e., stand) was minimal for most properties.

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Historical Patterns of Forest Fertilization in the Southeastern United States from 1969 to 2004

Southern Journal of Applied Forestry ◽

10.1093/sjaf/31.3.129 ◽

2007 ◽

Vol 31 (3) ◽

pp. 129-137 ◽

Cited By ~ 47

Author(s):

Timothy J. Albaugh ◽

H. Lee Allen ◽

Thomas R. Fox

Keyword(s):

United States ◽

Loblolly Pine ◽

Southeastern United States ◽

The United States ◽

Fertilizer Application ◽

Diammonium Phosphate ◽

Forest Fertilization ◽

Nitrogen And Phosphorus ◽

Research Results ◽

Pinus Taeda L

Abstract Based on historical forest fertilization survey records, over 16 million ac were fertilized in the southeastern United States from 1969 to 2004, with the peak forest fertilizer application in 1999, when 1.59 million ac were fertilized. The 1999 applications were largely on loblolly pine (Pinus taeda L.; 91%) in established stands (78%) and included both nitrogen and phosphorus, typically as urea and diammonium phosphate fertilizers, respectively. On a tonnage basis from 2000 to 2004, the average amount of forest-applied urea and diammonium phosphate represented 2.5% of those materials applied in the United States. The number of acres fertilized approximately doubled every 2 years from 1991 through 1999. This increase can be attributed to a shift in forest production interests to the southeastern United States at a time when research results were showing positive biological and economic responses to nitrogen and phosphorus applications in midrotation southern pine stands. Common application rates for nitrogen and phosphorus were 200 and 50 lb elemental nitrogen ac−1and 25 and 50 lb elemental phosphorus ac−1 for stands >2 years old and ≤2 years old, respectively. In 1994, application of elements other than nitrogen and phosphorus, including potassium, boron, and magnesium, began in response to newly available research results. Boron was applied to 30% of the total number of acres fertilized in 2004, likely because boron, when applied with urea, may reduce nitrogen volatilization.

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Effect of Mid-Rotation Fertilization on Stiffness and Strength of Loblolly Pine Wood

IAWA Journal ◽

10.1163/22941932-00000011 ◽

2013 ◽

Vol 34 (2) ◽

pp. 127-134 ◽

Cited By ~ 1

Author(s):

Finto Antony ◽

Laurence R. Schimleck ◽

Richard F. Daniels ◽

Alexander Clark

Keyword(s):

Loblolly Pine ◽

Treatment Effect ◽

Nitrogen Fertilizer ◽

Modulus Of Elasticity ◽

Block Design ◽

Modulus Of Rupture ◽

Significant Treatment Effect ◽

Significant Treatment ◽

Randomized Complete Block Design ◽

Four Levels

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.

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Modeling Early Responses of Loblolly Pine Growth to Thinning in the Western Gulf Coastal Plain Region

Forest Science ◽

10.1093/forsci/fxaa009 ◽

2020 ◽

Vol 66 (5) ◽

pp. 623-633

Author(s):

Y H Weng ◽

J Grogan ◽

D W Coble

Keyword(s):

Loblolly Pine ◽

Basal Area ◽

Tree Height ◽

Height Growth ◽

Growth Responses ◽

Individual Tree ◽

Large Trees ◽

The Difference ◽

Pinus Taeda L ◽

Stand Basal Area

Abstract Growth response to thinning has long been a research topic of interest in forest science. This study presents the first 3–4 years of response of loblolly pine (Pinus taeda L.) growth to thinning at different intensities. Data were collected from the East Texas Pine Research Project’s region-wide loblolly pine thinning study, which covers a wide variety of stand conditions. Four treatments, light, moderate, and heavy thinning, respectively having 370, 555, and 740 residual trees per hectare after thinning, and an unthinned control, were included. Individual tree diameter at breast height (dbh) and total height were recorded annually for the first 3–4 years after thinning. Results indicate significant differences between treatments in dbh growth in each year after thinning, as well as for all years combined. Each thinning treatment had significantly greater dbh growth than the control in the first growing season with this positive response being more evident in the case of the heavier thinning or at the later years post-thinning. Conversely, the thinning effect on tree height growth was initially negligibly negative, then becoming positive after 2–4 years, with the heavier thinning becoming positive sooner. Tree size class, assigned based on prethinning dbh, had a significant effect on both dbh and height growth responses. Compared to the control, small trees had a greater response both in dbh and in height growth than the medium and large trees over the measurement period. At the stand level, the heavier thinning had significantly less stand basal area per hectare, but the difference in stand basal area per hectare between the thinned and the unthinned plots decreased with years post-thinning. Results from this study can improve our understanding in thinning effects and help forest managers make accurate decisions on silvicultural regimes.

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Nantucket Pine Tip Moth, Rhyacionia frustrana (Comstock) (Insecta: Lepidoptera: Tortricidae)

EDIS ◽

10.32473/edis-in581-2003 ◽

1969 ◽

Vol 2005 (2) ◽

Author(s):

Wayne N. Dixon

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

The United States ◽

Cooperative Extension Service ◽

University Of Florida ◽

Pine Seedlings ◽

Nantucket Pine Tip Moth ◽

Rhyacionia Frustrana ◽

Growth Loss ◽

Pinus Taeda L

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), is a serious pest of young pine in plantations, wild pine seedlings in open areas, Christmas tree plantings, ornamental pines, and pine seed orchards in the United States. Growth loss and stem deformity, caused by larvae feeding inside growing shoots, buds, and conelets, can be considerable during the first five years when most damage occurs (Yates et al. 1981). The increasing population of a preferred host species, loblolly pine (Pinus taeda L.), in Florida poses an ever-increasing problem of Nantucket pine tip moth infestations. This document is EENY-304 (originally published as DPI Entomology Circular 298), one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: August 2003. EENY304/IN581: Nantucket Pine Tip Moth, Rhyacionia frustrana (Comstock) (Insecta: Lepidoptera: Tortricidae) (ufl.edu)

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Population density influences assessment and application of site index

Canadian Journal of Forest Research ◽

10.1139/x00-079 ◽

2000 ◽

Vol 30 (9) ◽

pp. 1472-1475 ◽

Cited By ~ 30

Author(s):

David W MacFarlane ◽

Edwin J Green ◽

Harold E Burkhart

Keyword(s):

Loblolly Pine ◽

Geographic Location ◽

Stand Density ◽

Tree Height ◽

Significant Negative Correlation ◽

Site Index ◽

Height Growth ◽

Planting Density ◽

Site Quality ◽

Pinus Taeda L

The height growth of dominant trees in plantations is often assumed to be independent of initial planting density. This assumption allows for the use of dominant tree height as an index of site quality. We found that this assumption was false for the seven tallest trees in 184 even-aged loblolly pine (Pinus taeda L.) stands, planted at nine initial planting densities, at four different geographic locations. A strong, highly significant negative correlation was found between dominant height and initial planting density for stands 14 and 16 years of age. This leads to large differences in predicted site index for stands with different initial planting densities planted at the same geographic location. Use of these site indices to predict yield produced large differences in predicted yield (m3/ha) at age 25. These results provide strong evidence for density-dependent height growth, even for dominant trees in the stand, and suggest that site index, used as a measurement of site quality, is confounded with stand density.

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Relative resistance to breaking of Pinus taeda and Pinus palustris

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpy038 ◽

2018 ◽

Vol 92 (4) ◽

pp. 417-424 ◽

Cited By ~ 3

Author(s):

Cory Garms ◽

Thomas J Dean

Keyword(s):

Loblolly Pine ◽

Modulus Of Elasticity ◽

Longleaf Pine ◽

Basal Area ◽

Bending Moment ◽

Pinus Palustris ◽

Modulus Of Rupture ◽

Pine Wood ◽

Pine Tree ◽

Crown Length

Abstract Patterns from hurricane damage indicate that longleaf pine is more windfirm than loblolly pine. Tree windfirmess has been attributed to many factors including species and material properties like wood strength and stiffness. Because longleaf pine wood is stronger and stiffer than loblolly pine wood, this study used static winching methodology to see if these properties account for differences in wind firmness by measuring bending force required to break stems (MMAX). Stress–strain diagrams were constructed for pulled trees to explore how they behave under increasing loads. Based on these diagrams, living trees appear to act as linear elastic materials as they experience increasing static lateral stress. As expected, longleaf pine stems were stiffer than loblolly pine wood in situ based on Young’s modulus of elasticity. Tree basal area was the best predictor of MMAX for both species, however, species had no significant effect on the maximum bending moment required to break tree stems of a given basal area for these trees under these conditions. The stiffness of the stems was higher for longleaf than loblolly as indicated by the modulus of elasticity, but the strength of the stems as indicated by the modulus of rupture was not significantly different between the species. Differences in the volumetric density of foliage, however, were consistent with the observed differences in stem failure between the species. For trees with the same diameter, loblolly pine had higher values of leaf area per unit crown length than longleaf pine.

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Forest Nursery Practices in the South

Southern Journal of Applied Forestry ◽

10.1093/sjaf/8.2.67 ◽

1984 ◽

Vol 8 (2) ◽

pp. 67-75 ◽

Cited By ~ 9

Author(s):

James N. Boyer ◽

David B. South

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Cover Crops ◽

The United States ◽

The Past ◽

Pine Seedlings ◽

Nursery Practices ◽

Forest Nurseries ◽

Bare Root ◽

Pinus Taeda L

Abstract Southern forest nurseries produce 80 percent of the bare-root seedlings grown in the United States (nearly 1.3 billion out of 1.6 billion in 1980). Loblolly pine (Pinus taeda L.) alone accounts for most of the reforestation in this country. Responses by southern nurserymen to a questionnaire were compiled in order to document the practices currently employed to produce southern pine seedlings. In comparison with forest industry nurseries, public nurseries tend to be older and larger, are less mechanized, employ more handweeding, use less cover crops, and produce a greater number of species. The most notable changes occurring in the past 50 years include increased production, a change in the favored species produced, increased chemical pest control, increased mechanical harvesting, and a shift in nursery site selection to sandier soils.

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