A comparison of methods for edge-bias compensation

1998 ◽  
Vol 28 (6) ◽  
pp. 942-945 ◽  
Author(s):  
Philip J Radtke ◽  
Harold E Burkhart
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Age ◽  
Tree Crown ◽  
Individual Tree ◽  
Plot Size ◽  
Random Arrangement ◽  
Pinus Taeda L ◽  
Crown Closure ◽  
Bias Compensation

Ignoring the effects of off-plot trees on variables measured within a plot boundary may result in the under estimation problem known as edge bias. A number of edge bias compensation techniques have been proposed in the literature. Four of these were compared with the alternative of ignoring off-plot trees to determine their relative adequacy in modeling crown closure from individual tree crown measurements. Data from a spacing trial of loblolly pine (Pinus taeda L.) were used to make the comparisons. By shrinking the effective size of experimental plots, measurements of "off-plot" data were made available to compare with the results of edge-bias compensation models. Three edge-bias compensation algorithms were found to perform equivalently well: translation; reflection via a reflecting line through the edge trees; and a random arrangement of interior trees around the plot. The ability of the models to compensate for edge bias declined with stand age. Furthermore,the variability of compensation values increased with age and as plot size was reduced.

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

1998 ◽  
Vol 28 (9) ◽  
pp. 1344-1351 ◽  
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.

Eight-Year Performance of Loblolly Pine with Pisolithus Ectomycorrhizae on a Good-Quality Forest Site

1988 ◽  
Vol 12 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Donald H. Marx ◽  
Charles E. Cordell ◽  
Alexander Clark
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Forest Site ◽  
Water Deficits ◽  
Growing Seasons ◽  
Area Growth ◽  
Pinus Taeda L ◽  
Crown Closure

Abstract Loblolly pine (Pinus taeda L) seedlings with different initial amounts of Pisolithus tinctorius (Pt) ectomycorrhizae (Pt index 0, 27, 46, 68, or 88) were planted on a good-quality site (site index 90 ft at age 50) in southwest Georgia. After 8 years and crown closure, trees with Pt indices of 88 and 68 had significantly better survival and greater heights, diameters, volumes, and green weights per tree and per ac than nursery-run, control seedlings (Pt index 0). Volume and weight yields per ac were over 50% greater and volume and weight yields per tree were over 20% greater for trees in the Pt index 88 treatment than they were for control trees. A special statistical analysis indicated that average per ac volume was positively correlated with initial Pt index values larger than 58. Tree-ring analyses showed that trees with a Pt index of 88 had significantly greater annual basal area growth than controls during growing seasons with water deficits of 8 to 13 in. Annual growth did not differ when water deficits were greater or less than these amounts. After 8 years, Pt basidiocarps were present throughout the study site. Mycorrhizal treatment integrity may have been lost after 3 or 4 years. South. J. Appl. For. 12(4):275-280

Effects of competition control and annual nitrogen fertilization on gas exchange of different-aged Pinus taeda

2003 ◽  
Vol 33 (6) ◽  
pp. 1076-1083 ◽  
Author(s):  
Gregory T Munger ◽  
Rodney E Will ◽  
Bruce E Borders
Keyword(s):  
Gas Exchange ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Positive Impact ◽  
Leaf Gas Exchange ◽  
Nitrogen Concentration ◽  
Net Photosynthesis ◽  
Stand Age ◽  
Competition Control ◽  
Pinus Taeda L

To determine the importance of competition control and annual fertilization on leaf gas exchange, light-saturated net photosynthesis (Asat), stomatal conductance (gs), and internal CO2 concentration (Ci) were measured multiple times in different-aged loblolly pine (Pinus taeda L.) stands growing at a Piedmont (BF Grant) and Coastal Plain (Waycross) location in Georgia, U.S.A. At both locations, competition control decreased Asat and gs (Asat from 4.53 to 4.12 µmol·m–2·s–1, gs from 0.058 to 0.050 mol·m–2·s–1 at BF Grant; Asat from 4.22 to 4.01 µmol·m–2·s–1, gs from 0.054 to 0.049 mol·m–2·s–1 at Waycross). Overall, fertilization did not have a positive impact on Asat, even though fertilization significantly increased foliar nitrogen concentration. At BF Grant, fertilization significantly decreased gs from 0.057 to 0.051 mol·m–2·s–1 and Ci from 217 to 205 µmol·mol–1. In addition, the decrease in Ci associated with fertilization became larger with stand age. At Waycross, fertilization decreased Ci from 211 to 203 µmol·mol–1 and the interaction between fertilization and stand age was significant for gs and Ci. These results indicate that silivcultural practices that increase resource availability and stand growth did not enhance leaf gas exchange.

Stand Density Management Diagram for Loblolly Pine Plantations in North Louisiana

1994 ◽  
Vol 18 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Roger A. Williams
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Density Relationship ◽  
Stand Density Management ◽  
Pinus Taeda L ◽  
Stand Density Index ◽  
Crown Closure ◽  
North Louisiana ◽  
Stand Density Management Diagram

Abstract A stand density management diagram for use with loblolly pine (Pinus taeda L.) plantations in north Louisiana has been developed. Three critical stand density boundaries important to management were defined: (1) the point of crown closure, (2) the point of self-thinning, and (3) the maximum tree size-stand density relationship. These three boundaries were estimated to occur at stand density index values of 160, 220, and 400, respectively. Three examples illustrating the use of these boundaries in thinning strategies are presented. South. J. Appl. For. 18(1):40-45.

scholarly journals A Consensus Map for Loblolly Pine (Pinus taeda L.). I. Construction and Integration of Individual Linkage Maps From Two Outbred Three-Generation Pedigrees

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 321-330 ◽  
Author(s):  
Mitchell M Sewell ◽  
Bradley K Sherman ◽  
David B Neale
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Fragment Length Polymorphism ◽  
Random Amplified Polymorphic Dna ◽  
Mapping Function ◽  
Genetic Maps ◽  
Linkage Data ◽  
Linkage Maps ◽  
Consensus Map ◽  
Pinus Taeda L

Abstract A consensus map for loblolly pine (Pinus taeda L.) was constructed from the integration of linkage data from two unrelated three-generation outbred pedigrees. The progeny segregation data from restriction fragment length polymorphism, random amplified polymorphic DNA, and isozyme genetic markers from each pedigree were recoded to reflect the two independent populations of parental meioses, and genetic maps were constructed to represent each parent. The rate of meiotic recombination was significantly greater for males than females, as was the average estimate of genome length for males {1983.7 cM [Kosambi mapping function (K)]} and females [1339.5 cM(K)]. The integration of individual maps allows for the synthesis of genetic information from independent sources onto a single consensus map and facilitates the consolidation of linkage groups to represent the chromosomes (n = 12) of loblolly pine. The resulting consensus map consists of 357 unique molecular markers and covers ∼1300 cM(K).

Long-term effects of stand density management and genotype on wood properties of loblolly pine (Pinus taeda L.) in the mid-South USA

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Wood Properties ◽  
Long Term Effects ◽  
Stand Density Management ◽  
Pinus Taeda L

scholarly journals Four Site-Preparation Techniques for Regenerating Pine-Hardwood Mixtures in the Piedmont

1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Height Growth ◽  
Site Preparation ◽  
Site Conditions ◽  
Growing Seasons ◽  
Southern Appalachian ◽  
Medium Quality ◽  
Pinus Taeda L ◽  
Preparation Techniques

Abstract Four variations of the fell-and-burn technique, a system developed to produce mixed pine-hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing of felling residual stems, as prescribed by the fell-and-burn technique, may be flexible because winter and spring felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of the first growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods within four growing seasons in burned plots and within six growing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122.

scholarly journals Genotypic Stability Effects on Predicted Family Responses to Silvicultural Treatments in Loblolly Pine

1997 ◽  
Vol 21 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Steven E. McKeand ◽  
Robert P. Crook ◽  
H. Lee Allen
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Responses ◽  
Intensive Culture ◽  
Genotype By Environment ◽  
Silvicultural Treatments ◽  
Genotypic Stability ◽  
Superior Genotypes ◽  
Using Data ◽  
Pinus Taeda L

Abstract The lack of rank change in growth characteristics when open-pollinated families of loblolly pine (Pinus taeda L.) are planted on different sites in the Southeast has greatly simplified breeding for superior genotypes. Although family rank does not usually change, genotype by environment interactions (GxE) may be very important in operational deployment of families in regeneration programs. Using data from GxE trials and two site preparation-fertilization-herbicide trials, we estimated the growth that different families should achieve following application of these silvicultural practices. Better performing families tend to be most responsive to site changes (i.e. genetically unstable). Growth responses to silvicultural treatment will be overestimated if only the most responsive families are used in silvicultural research trials. Similarly, genetic gains will be overestimated if gain trials are planted on only the best sites or receive intensive culture. South. J. Appl. For. 21(2):84-89.

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