A Stochastic Frontier Model for Fitting Tree Crown Shape in Loblolly Pine (Pinus taeda L.)

1996 ◽  
Vol 1 (3) ◽  
pp. 336 ◽  
Author(s):  
Sunil K. Nepal ◽  
Greg L. Somers ◽  
Steven B. Caudill
1998 ◽  
Vol 28 (6) ◽  
pp. 942-945 ◽  
Author(s):  
Philip J Radtke ◽  
Harold E Burkhart

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.


Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 321-330 ◽  
Author(s):  
Mitchell M Sewell ◽  
Bradley K Sherman ◽  
David B Neale

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).


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

1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop

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.


1997 ◽  
Vol 21 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Steven E. McKeand ◽  
Robert P. Crook ◽  
H. Lee Allen

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.


BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Mengmeng Lu ◽  
Konstantin V. Krutovsky ◽  
C. Dana Nelson ◽  
Tomasz E. Koralewski ◽  
Thomas D. Byram ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document