Genetic variation in basic density and modulus of

Authors: G R Johnson Barbara L Gartner

Publish Date: 2006/08/24

Volume: 3, Issue: 1, Pages: 25-33

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Abstract

Douglasfir trees from 39 openpollinated families at four test locations were assessed to estimate heritability of modulus of elasticity MOE and basic density After trees were felled sound velocity was measured on 4m logs with the Director HM200 Disks were taken to estimate dry and green wood density dynamic MOE was estimated as green density × sound velocity2 Heritability estimates of MOE acrosssite h 2=055 were larger than those for total height 015 and diameter at breast height DBH 029 and similar to those for density 059 Negative genetic correlations were found for MOE with height r A=−030 and DBH r A=−051 and were similar to those found for density with height r A=−052 and DBH r A=−057 The partial correlations of height with MOE and density while holding DBH constant were positive implying that the observed negative correlations between height and the wood properties were a function of the high positive correlation between height and DBH and the strong negative correlations between DBH and the wood properties Taper DBH/height−14 was found to be negatively associated with MOE Selection for MOE may produce greater gains than selection for density because MOE had a larger coefficient of additive variation 96 than density 51 Conversely selection for growth may have a more negative impact on MOE than density because of the greater genetic variation associated with MOE Family mean correlations of the wood quality traits with stem form and crown health were mostly nonsignificantThis research was supported by the Sustainable Forestry component of Agenda 2020 a joint effort of the US Department of Agriculture Forest Service Research and Development and the American Forest and Paper Association a special grant from the USDA to Oregon State University for wood utilization research the Swiss Needle Cast Cooperative and the Oregon Department of Forestry Data and analyses were also provided by the Northwest Tree Improvement Cooperative Field assistance was provided by Steve Skinner and Joe Travers of the Oregon Department of Forestry and the chainsaw crew from the Oregon Department of Corrections Nicole Suty helped with some of the measurements Helpful reviews were provided by Rowland Burdon Marilyn Cherry Keith Jayawickrama Leith Knowles Satish Kumar Nancy Mandel Charles Sorensson Michael Stoehr and three anonymous reviewers

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