Keith Jayawickrama

Jayawickrama, Keith

Position Type:
Job Title:
Director of the Northwest Tree Improvement Cooperative
Forest Ecosystems & Society
Office Location:
220 Richardson Hall
Phone Number:
B.S., University of Colombo, 1986
M.S., North Carolina State University, 1990
M.Stat, North Carolina State University, 1996
Ph.D., North Carolina State University, 1996
Research Interests
  • Forest Genetics
  • Tree Breeding
My priority is promoting, directing, and supporting cooperative tree improvement activities for important conifer species (Douglas-fir, western hemlock, coastal redwood, and western red cedar) in the US Pacific Northwest.
Selected Publications:
  1. Jayawickrama, KJS and Ye, TZ. 2020. Cooperative Second-Cycle Breeding and Test¬ing of Coastal Douglas-fir in the US Pacific Northwest: Strategy, Implementation, and Op¬erational Aspects. Silvae Genetica (2020) 69, 98 – 107.
  2. Joo, S, Maguire, DA, Jayawickrama, KJS, Ye, TZ, J. and St. Clair JB. 2020. Estimation of yield gains at rotation-age from genetic tree improvement in coast Douglas-fir. Forest Ecology and Management. 466 (2020) 117930
  3. Howe, GT, Jayawickrama, K, Kolpak SE, Kling, J, Trappe, M, Hipkins, V, Ye, T, Guida, S, Cronn, R, Cushman, SA and McEvoy, S. 2020. An Axiom SNP genotyping array for Douglas-fir. BMC Genomics (2020) 21:9.
  4. Geleynse, Scott, Keith Jayawickrama, Matt Trappe, Terrance Ye & Xiao Zhang 2016. Genetic Parameters of Factors Affecting the Biomass Recalcitrance of Douglas Fir Trees. BioEnergy Research DOI 10.1007/s12155-016-9718-2
  5. Lowell, E.C., Maguire, D.A. Briggs, D.G., Turnblom, E.C., Jayawickrama, K. J.S. and Bryce, J. 2014. Effects of Silviculture and Genetics on Branch/Knot Attributes of Coastal Pacific Northwest Douglas-Fir and Implications for Wood Quality—A Synthesis. Forests 2014, 5, 1717-1736; doi:10.3390/f5071717
  6. Ye, T.Z and Jayawickrama, K.J.S. 2014. Geographic variation and local growth superiority for coastal Douglas-fir – rotation-age growth performance in a Douglas-fir provenance test. Silvae Genetica 59(1): 29-39.
  7. Geleynse, S., Alvarez-Vasco, C., Garcia, K., Jayawickrama, K., Trappe, M. and Zhang, X. 2014. A Multi-Level Analysis Approach to Measuring Variations in Biomass Recalcitrance of Douglas fir Tree Samples. BioEnergy Research DOI:10.1007/s12155-014-9483-z
  8. Urhan, O., Kolpak, S.E., Jayawickrama, KJS, Howe, GT. 2014. Early genetic selection for wood stiffness in juvenile Douglas-fir and western hemlock Forest Ecology and Management 320: 104-117.
  9. Jayawickrama K.J.S., L.K. Miller and D.W. Cress 2013. Coastal Douglas-Fir Controlled Crossing Guidelines. Tree Planters Notes 56(1): 60-73
  10. Ye, T. Z. and Jayawickrama, K.J.S. 2012. Early selection for improving volume growth in coastal Douglas-fir breeding programs. Silvae Genetica 61(4-5): 186-198.
  11. Jayawickrama KJS Ye, TZ and Howe, G. 2010. Heritabilities, intertrait genetic correlations, G x E interaction and predicted genetic gains for acoustic velocity in mid-rotation coastal Douglas fir. Silvae Genetica 60(1): 8-18.
  12. Ye, TZ, Jayawickrama KJS and St Clair JB. 2009. Realized gains from block-plot coastal Douglas-fir trials in the Northern Oregon Cascades. Silvae Genetica 59(1): 29-39.
  13. Ye, T. Z. and Jayawickrama, K. J. S. 2008. Efficiency of using spatial analysis in first-generation coastal Douglas-fir progeny tests in the US Pacific Northwest. Tree Genetics & Genomes 4: 677-692.
  14. McKeand SE, Li B, Grissom JE, Isik F and Jayawickrama KJS. 2008. Genetic parameter estimates for growth traits from diallel tests of loblolly pine throughout the southeastern United States. Silvae Genetica 57:101-110.
  15. Ye, Terrance Z., Jayawickrama Keith JS, and Johnson GR. 2007. Efficiency of Including First-generation Information in Second-generation Ranking and Selection: Results of Computer Simulation. Tree Genetics and Genomes 3: 319-328.
  16. Howe, G, K Jayawickrama, GR Johnson, M Cherry and NC Wheeler. 2005. Breeding Douglas-fir. Invited book chapter on the genetic improvement of Douglas-fir. Pp. 245-353. In: Plant Breeding Reviews, v. 27. J. Janick (ed). John Wiley and Sons, Inc.