Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees), with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars.
References
[1]
Zalesny, R.S., Jr.; Donner, D.M.; Coyle, D.R.; Headlee, W.L. An approach for siting poplar energy production systems to increase productivity and associated ecosystem services. For. Ecol. Manag. 2012, 284, 45–58, doi:10.1016/j.foreco.2012.07.022.
[2]
Millennium Ecosystem Assessment (MEA). In Ecosystems and Human Well-Being: Synthesis; Island Press: Washington, DC, USA, 2005; p. 155.
[3]
Thelemann, R.; Johnson, G.; Sheaffer, C.; Banerjee, S.; Cai, H.; Wyse, D. The effect of landscape position on biomass crop yield. Agron. J. 2010, 102, 513–522, doi:10.2134/agronj2009.0058.
[4]
Headlee, W.L. Productivity and Biometry of Hybrid Poplars with Respect to Establishment, Regeneration, Regional Modeling, and Utilization of Bio-Energy Byproducts. Ph.D. Thesis, Iowa State University, Ames, IA, USA, 2012.
[5]
Burken, J.G.; Schnoor, J.L. Predictive relationships for uptake of organic contaminants by hybrid poplar trees. Environ. Sci. Technol. 1998, 32, 3379–3385, doi:10.1021/es9706817.
[6]
Zalesny, J.A.; Zalesny, R.S., Jr.; Wiese, A.H.; Sexton, B.T.; Hall, R.B. Uptake of macro- and micro-nutrients into leaf, woody, and root tissue of Populus after irrigation with landfill leachate. J. Sust. For. 2008, 27, 303–327, doi:10.1080/10549810802256262.
[7]
Headlee, W.L.; Zalesny, R.S., Jr.; Donner, D.M.; Hall, R.B. Using a process-based model (3-PG) to predict and map hybrid poplar biomass productivity in Minnesota and Wisconsin, USA. Bioenergy Res. 2013, 6, 196–210, doi:10.1007/s12155-012-9251-x.
[8]
Stanton, B.; Eaton, J.; Johnson, J.; Rice, D.; Schuette, B.; Moser, B. Hybrid poplar in the Pacific Northwest: The effects of a market-driven management. J. For. 2002, 100, 28–33.
[9]
Johnson, J.M.F.; Coleman, M.D.; Gesch, R.; Jaradat, A.; Mitchell, R.; Reicosky, D.; Wilhelm, W.W. Biomass-bioenergy crops in the United States: A changing paradigm. Am. J. Plant Sci. Biotechnol. 2007, 1, 1–28.
[10]
U.S. Department of Energy. U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry; Perlack, R.D., Stokes, B.J., Eds.; Oak Ridge National Laboratory: Oak Ridge, TN, USA, 2011; p. 227.
[11]
Langholtz, M.; Graham, R.; Eaton, L.; Perlack, R.; Hellwinkel, C.; de la Torre Ugarte, D. Price projections of feedstocks for biofuels and biopower in the U.S. Energy Pol. 2012, 41, 484–493, doi:10.1016/j.enpol.2011.11.009.
[12]
Berndes, G.; Hoogwijk, M.; van den Broek, R. The contribution of biomass in the future global energy supply: A review of 17 studies. Biomass Bioenergy 2003, 25, 1–28, doi:10.1016/S0961-9534(02)00185-X.
[13]
Zhu, J.Y.; Pan, X.; Zalesny, R.S., Jr. Pretreatment of woody biomass for biofuel production: Energy efficiency, technologies, and recalcitrance. Appl. Microbiol. Biotechnol. 2010, 87, 847–857, doi:10.1007/s00253-010-2654-8.
[14]
Wang, Z.J.; Zhu, J.Y.; Zalesny, R.S., Jr.; Chen, K.F. Ethanol production potential from poplar wood through enzymatic saccharification and fermentation. Fuel 2012, 95, 606–614, doi:10.1016/j.fuel.2011.12.032.
[15]
Jenkins, B.M.; Baxter, L.L.; Miles, T.R., Jr.; Miles, T.R. Combustion properties of biomass. Fuel Proc. Technol. 1998, 54, 17–46, doi:10.1016/S0378-3820(97)00059-3.
[16]
Weber, J.C.; Stettler, R.F.; Heilman, P.E. Genetic variation and productivity of Populus trichocarpa and its hybrids. I. Morphology and phenology of 50 native clones. Can. J. For. Res. 1985, 15, 376–383, doi:10.1139/x85-060.
[17]
Rajora, O.P.; Zsuffa, L. Allozyme divergence and evolutionary relationships among Populus deltoides, P. nigra, and P. maximowiczii. Genome 1990, 33, 44–49.
[18]
Eckenwalder, J.E. Systematics and Evolution of Populus. In Biology of Populus and Its Implications for Management and Conservation; Stettler, R.F., Bradshaw, H.D., Jr., Heilman, P.E., Hinckley, T.M., Eds.; NRC Research Press, National Research Council of Canada: Ottawa, ON, Canada, 1996. Chapter 1; pp. 7–32.
[19]
Kenney, W.A.; Sennerby-Forsse, L.; Layton, P. A review of biomass quality research relevant to the use of poplar and willow for energy conversion. Biomass 1990, 21, 163–188, doi:10.1016/0144-4565(90)90063-P.
[20]
Kenney, W.A.; Gambles, R.L.; Sennerby-Forsse, L. Feedstock Characteristic and Quality. In Ecophysiology of Short Rotation Forest Crops; Mitchell, C.P., Ford-Robertson, J.B., Hinckley, T., Sennerby-Forsse, L., Eds.; Elsevier: London, UK, 1992. Chapter 10; pp. 267–284.
[21]
Mátyás, C.; Peszlen, I. Effect of age on selected wood quality traits of poplar clones. Silvae Gen. 1997, 46, 64–72.
[22]
Tharakan, P.J.; Volk, T.A.; Abrahamson, L.P.; White, E.H. Energy feedstock characteristics of willow and hybrid poplar clones at harvest age. Biomass Bioenergy 2003, 25, 571–580, doi:10.1016/S0961-9534(03)00054-0.
[23]
Pliura, A.; Yu, Q.Y.; Zhang, S.Y.; MacKay, J.; Périnet, P.; Bousquet, J. Variation in wood density and shrinkage and their relationship to growth of selected young poplar hybrid crosses. For. Sci. 2005, 51, 472–482.
[24]
Pliura, A.; Zhang, S.Y.; MacKay, J.; Bousquet, J. Genotypic variation in wood density and growth traits of poplar hybrids at four clonal trials. For. Ecol. Manag. 2007, 238, 92–106, doi:10.1016/j.foreco.2006.09.082.
[25]
Olson, J.R.; Jourdain, C.J.; Rousseau, R.J. Selection for cellulose content, specific gravity, and volume in young Populus deltoides clones. Can. J. For. Res. 1985, 15, 393–396, doi:10.1139/x85-063.
[26]
Kord, B.; Kialashaki, A.; Kord, B. The within-tree variation in wood density and shrinkage, and their relationship in Populus euramericana. Turk. J. Agric. For. 2010, 34, 121–126.
[27]
Riemenschneider, D.E.; Berguson, W.E.; Dickmann, D.I.; Hall, R.B.; Isebrands, J.G.; Mohn, C.A.; Stanosz, G.R.; Tuskan, G.A. Poplar breeding and testing strategies in the north-central US: Demonstration of potential yield and consideration of future research needs. For. Chron. 2001, 77, 245–253.
[28]
Beaudoin, M.; Hernández, R.E.; Koubaa, A.; Poliquin, J. Interclonal, intraclonal and within-tree variation in wood density of poplar hybrid clones. Wood Fiber Sci. 1992, 24, 147–153.
[29]
Geyer, W.A.; DeWyke, J.; Walawender, W.P. Biomass and gasification properties of young Populus clones. Wood Fiber Sci. 2000, 32, 375–384.
[30]
DeBell, D.S.; Singleton, R.; Harrington, C.A.; Gartner, B.L. Wood density and fiber length in young Populus stems: Relation to clone, age, growth rate, and pruning. Wood Fiber Sci. 2002, 34, 529–539.
[31]
Ivkovich, M. Genetic variation of wood properties in balsam poplar (Populus balsamifera L.). Silvae Gen. 1996, 45, 119–124.
[32]
Hernández, R.E.; Koubaa, A.; Beaudoin, M.; Fortin, Y. Selected mechanical properties of fast-growing poplar hybrid clones. Wood Fiber Sci. 1998, 30, 138–147.
[33]
Zhang, S.Y.; Yu, Q.; Chauret, G.; Koubaa, A. Selection for both growth and wood properties in hybrid poplar clones. For. Sci. 2003, 49, 1–8.
[34]
Semen, E.; Kuo, M.; Su, Y.C.; Hall, R.B.; Stokke, D.D. Physical properties of kraft pulp from four-year-old aspen hybrids and crosses. Wood Fiber Sci. 2001, 33, 140–147.
[35]
Blankenhorn, P.R.; Bowersox, T.W.; Strauss, C.H.; Kessler, K.R.; Stover, L.R.; Kilmer, W.R.; DiCola, M.L. Effects of management strategy and site on specific gravity of a Populus hybrid clone. Wood Fiber Sci. 1992, 24, 274–279.
[36]
Murphey, W.K.; Bowersox, T.W.; Blankenhorn, P.R. Selected wood properties of young Populus hybrids. Wood Sci. 1979, 11, 263–267.
[37]
Zalesny, R.S., Jr.; Hall, R.B.; Zalesny, J.A.; Berguson, W.E.; McMahon, B.G.; Stanosz, G.R. Biomass and genotype × environment interactions of Populus energy crops in the Midwestern United States. Bioenergy Res. 2009, 2, 106–122, doi:10.1007/s12155-009-9039-9.
[38]
Hansen, E. Mid-Rotation Yields of Biomass Plantations in the North Central U.S.; Res. Pap. NC-309; U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: St. Paul, MN, USA, 1992; p. 8.
[39]
Hansen, E.A.; Ostry, M.E.; Johnson, W.D.; Tolsted, D.N.; Netzer, D.A.; Berguson, W.E.; Hall, R.B. Res. Paper NC-320; U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: St. Paul, MN, USA, 1994; p. 13.
[40]
Netzer, D.A.; Tolsted, D.; Ostry, M.E.; Isebrands, J.G.; Riemenschneider, D.E.; Ward, K.T. Growth, Yield, and Disease Resistance of 7- to 12-Year-Old Poplar Clones in the North Central United States; General Technical Report NC-229; U.S. Department of Agriculture, Forest Service, North Central Research Station: St. Paul, MN, USA, 2002; p. 31.
[41]
Web Soil Survey. Available online: http://websoilsurvey.nrcs.usda.gov (accessed on 21 February 2013).
[42]
National Climatic Data Center (NCDC) monthly summaries. Available online: http://www.ncdc.noaa.gov/oa/ncdc.html (accessed on 21 February 2013).
[43]
SAS Institute Inc. SAS Institute Inc: Cary, NC, USA, 2011.
[44]
Farmer, R.E. Variation and inheritance of eastern cottonwood growth and properties under two soil moisture regimes. Silvae Genet. 1970, 19, 5–8.
[45]
Pitre, F.E.; Pollet, B.; Lafarguette, F.; Cooke, J.E.K.; MacKay, J.J.; Lapierre, C. Effects of increased nitrogen supply on the lignification of poplar wood. J. Agric. Food Chem. 2007, 55, 10306–10314, doi:10.1021/jf071611e.
[46]
Hacke, U.G.; Plavcová, L.; Almeida-Rodriguez, A.; King-Jones, S.; Zhou, W.; Cooke, J.E.K. Influence of nitrogen fertilization on xylem traits and aquaporin expression in stems of hybrid poplar. Tree Physiol. 2010, 30, 1016–1025, doi:10.1093/treephys/tpq058.
