Total inside-bark volume is the most important selection criterion for productivity in tree breeding programs in the Southeastern U.S. Tree breeders typically estimate total inside-bark volume based on outside-bark diameter at breast height and total height without accounting for stem taper or bark thickness. To make a direct determination of total inside- and outside-bark volume, a loblolly pine (Pinus taeda L.) open-pollinated family trial replicated with cultural treatments of weed control and fertilization was measured. This direct measurement was compared to typical volume estimates. In this trial, approximately 40 individuals from each of 25 open-pollinated first- and second-generation families were destructively sampled in the 13th growing season. Selection for volume using a combined-variable (diameter2 * height) equation was found to be highly effective for making volume gain. There was a high correlation between estimated and directly-measured total inside-bark volumes (0.99). Bark thickness and stem taper had low importance for stem volume selection. There was a positive genetic correlation between bark thickness and diameter at breast height (0.66). This indicates that selection for larger diameters may produce individuals with thicker bark, which may eventually affect total inside-bark volume estimates.
AVERY, T. E. and H. E. BURKHART (2002): Forest measurements. 5th ed. McGraw-Hill. New York, N.Y. 456 p.
BALDWIN JR., V. C., K. D. PETERSON, A. CLARK III, R. B. FERGUSON, M. R. STRUB and D. R. BOWER (2000): The effects of spacing and thinning on stand and tree characteristics of 38-year-old loblolly pine. For. Ecol. and Manag. 137: 91-102.
BUFORD, M. A. and H. E. BURKHART (1987): Genetic improvement effects on growth and yield of loblolly pine plantations. For. Sci. 33: 707-724.
BURDON, R. D. (1975): Compression wood in Pinus radiata clones on four different sites. N. Z. J. For. Sci. 5: 152-164.
FALCONER, D. S. and T. F. C. MACKAY (1996): Introduction to quantitative genetics. 4th ed. Prentice Hall. Essex, England. 464 p.
GILMOUR, A. R., B. J. GOGEL, B. R. CULLIS, S. J. WELHAM and R. THOMPSON (2002): ASReml User Guide Release 1.0. VSN International Ltd., Hemel Hempstead, UK.
GOEBEL, N. B. and J. R. WARNER (1966): Volume tables for small diameter loblolly, shortleaf and Virginia pine in the upper South Carolina piedmont. Forest Research Series No. 7. Clemson University. Clemson, South Carolina.
ISIK, F., K. ISIK and S. J. LEE (1999): Genetic variation in Pinus brutia in Turkey: I. Growth, Biomass and Stem Quality Traits. For. Gene. 6: 89-99.
LARSON, P. R. (1963): Stem form development of forest trees. Vol. 5. Society of American Foresters. Washington, DC. 42 p.
LOEHLE, C. and G. NAMKOONG (1987): Constraints on tree breeding: Growth tradeoffs, growth strategies, and defense investments. For. Sci. 33: 1089-1097.
MCKEAND, S. E., E. J. JOKELA, D. A. HUBER, T. D. BYRAM, H. LEE ALLEN, B. LI and T. J. MULLIN (2006): Performance of improved genotypes of loblolly pine across different soils, climates, and silvicultural inputs. For. Ecol. and Manag. 227: 178-184.
MAGNUSSEN, S. (1995): The impact of genetic variation in relative growth rates on stem volume differentiation: a simulation study. Silvae Genet. 44: 194-205.
MATZIRIS, D. I. (2000): Genetic variation and realized genetic gain from Aleppo pine tree improvement. Silvae Genet. 49: 5-10.
NEWBERRY, J. D. and H. E. BURKHART (1986): Variableform stem profile models for loblolly pine. Can. J. For. Res. 16: 109-114.
PEDERICK, L. A. (1970): Variation and inheritance of stem form and bark thickness in young loblolly pine. Technical Report 41. School of Forest Resources, North Carolina State University. Raleigh, NC. 44 p.
SAS-INSTITUTE (2004): SAS Version 9 Cary, NC. SAS Institute, Inc.
SHELBOURNE, C. J. A. (1972): Genotype-environment interaction: Its study and its implications in forest tree improvement. P. 1-28 in Proc. of IUFRO Genetics. Tokyo, Japan.
SHERRILL, J. R. (2005): Genetic and cultural effects on stem taper and bark thickness in loblolly pine (Pinus taeda L.). Ms Thesis. North Carolina State University, Raleigh, NC. 91p.
SIERRA-LUCERO, V., S. E. MCKEAND, D. A. HUBER, D. L. ROCKWOOD and T. L. WHITE (2002): Performance differences and genetic parameters for four coastal provenances of loblolly pine in the Southeastern United States. For. Sci. 48: 732-742.
SPURR, S. H. (1952): Forest Inventory. Ronald Press Co. New York, NY. 476 p.
SVENSSON, J. C., S. E. MCKEAND, H. L. ALLEN and R. G. CAMPBELL (1999): Genetic variation in height and volume of loblolly pine open-pollinated families during canopy closure. Silvae Genet. 48: 204-207.
YAMADA, Y. (1962): Genotype by environment interaction and genetic correlation of the same trait under different environments. Jap. J. Genet. 37: 498-509.