Clonal variation in basic density, moisture content and heating value of wood, bark and branches in hybrid aspen

Hybrid aspen (Populus tremula × P. tremuloides) is one of the fastest growing tree species in Finland. During the mid-1990s, a breeding programme was started with the aim of selecting clones that were superior in producing pulpwood. Hybrid aspen can also be grown as a short-rotation crop for bioenergy. To study clonal variation in wood and bark properties, seven clones were selected from a 12-year-old field trial located in southern Finland. From each clone, five trees were harvested and samples were taken from stem wood, stem bark and branches to determine basic density, effective heating value, moisture and ash content. Vertical within-tree variation in moisture content and basic density was also studied. The differences between clones were significant for almost all studied properties. For all studied properties there was a significant difference between wood and bark. Wood had lower ash content (0.5% vs. 3.9%), basic density (378 kg m–3 vs. 450 kg m–3) and effective heating value (18.26 MJ kg–1 vs. 19.24 MJ kg–1), but higher moisture content (55% vs. 49%) than bark. The values for branches were intermediate. These results suggest that the properties of hybrid aspen important for energy use could be improved by clonal selection. However, selecting clones based on fast growth only may be challenging since it may lead to a decrease in hybrid aspen wood density.

[1]  J. Hytönen.  Biomass, nutrient content and energy yield of short-rotation hybrid aspen (P. tremula x P. tremuloides) coppice , 2018 .

[2]  A. Tullus,et al.  Above-ground growth and temporal plant–soil relations in midterm hybrid aspen (Populus tremula L. × P. tremuloides Michx.) plantations on former arable lands in hemiboreal Estonia , 2017 .

[3]  Y. Niu,et al.  Ash-related issues during biomass combustion: Alkali-induced slagging, silicate melt-induced slagging (ash fusion), agglomeration, corrosion, ash utilization, and related countermeasures , 2016 .

[4]  Eija Alakangas,et al.  Properties of indigenous fuels in Finland , 2016 .

[5]  O. Miezīte,et al.  Hybrid aspen clone wood mechanical properties. , 2016 .

[6]  E. Beuker,et al.  Growth potential of first generation hybrid aspen plantations in southern Finland , 2016 .

[7]  L. Rytter,et al.  Productivity and thinning effects in hybrid aspen root sucker stands , 2015 .

[8]  H. Böhlenius,et al.  Growth response of hybrid poplars to different types and levels of vegetation control , 2015 .

[9]  J. Nurmi,et al.  HEATING VALUE AND ASH CONTENT OF INTENSIVELY MANAGED STANDS , 2015 .

[10]  A. Jasińska,et al.  Increasing air humidity - a climate trend predicted for northern latitudes - alters the chemical composition of stemwood in silver birch and hybrid aspen. , 2014 .

[11]  Shawn D. Mansfield,et al.  Wood Quality and Growth Characterization across Intra- and Inter-Specific Hybrid Aspen Clones , 2013 .

[12]  M. Weih,et al.  Short-rotation forestry with hybrid aspen (Populus tremula L.×P. tremuloides Michx.) in Northern Europe , 2012 .

[13]  L. Dzurenda,et al.  Energy Characteristics of Wood-Chips Produced from Salix Viminalis - Clone ULV Energijska obiljeja iverja proizvedenoga od drva Salix viminalis - klona ULV , 2010 .

[14]  L. Pärn,et al.  Above-ground biomass characteristics of young hybrid aspen (Populus tremula L. x P. tremuloides Michx.) plantations on former agricultural land in Estonia , 2009 .

[15]  P. Diouf,et al.  Antioxidant properties and polyphenol contents of trembling aspen bark extracts , 2009, Wood Science and Technology.

[16]  H. Heräjärvi.  Effect of drying technology on aspen wood properties. , 2009 .

[17]  Henrik Heräjärvi,et al.  Variation of basic density and brinell hardness within mature Finnish Betula pendula and B. Pubescens stems , 2007 .

[18]  J. Nurmi,et al.  The characteristics of whole-tree fuel stocks from silvicultural cleanings and thinnings , 2007 .

[19]  H. Heräjärvi,et al.  Wood density and growth rate of European and hybrid aspen in Southern Finland , 2006 .

[20]  E. Verkasalo,et al.  Metsä- ja hybridihaapa sahatavaran ja jatkojalosteiden raaka-aineena , 2006 .

[21]  J. Azevedo,et al.  Estimating the higher heating value of biomass fuels from basic analysis data , 2005 .

[22]  J. Hytönen,et al.  Effects of competing vegetation and post-planting weed control on the mortality, growth and vole damages to Betula pendula planted on former agricultural land , 2005 .

[23]  H. Heräjärvi.  Static bending properties of Finnish birch wood , 2004, Wood Science and Technology.

[24]  L. Rytter,et al.  Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.) , 2003 .

[25]  R. Alén,et al.  Genetic Control of Wood Physicochemical Properties, Growth, and Phenology in Hybrid Aspen Clones , 2001 .

[26]  T. Kärki.  Variation of wood density and shrinkage in European aspen (Populus tremula) , 2001, Holz als Roh- und Werkstoff.

[27]  E. Beuker.  Aspen breeding in Finland, new challenges , 2000 .

[28]  Ralph E.H. Sims,et al.  Fuel characteristics of short rotation forest biomass , 1999 .

[29]  J. Hynynen.  Haavan ja hybridihaavan kasvu ja tuotos. , 1999 .

[30]  Juha Nurmi,et al.  Heating values of mature trees. , 1997 .

[31]  Juha Nurmi,et al.  Heating values of the above ground biomass of small-sized trees. , 1993 .

[32]  U. Gullberg,et al.  Genetic variation in a 26‐year old hybrid aspen trial in southern Sweden , 1993 .

[33]  Raili Voipio,et al.  Pienikokoisten puiden maanpäällisen biomassan kemiallinen koostumus. , 1992 .

[34]  G. Tsoumis,et al.  Science and technology of wood : structure, properties, utilization , 1991 .

[35]  W. A. Kenney,et al.  A review of biomass quality research relevant to the use of poplar and willow for energy conversion , 1990 .

[36]  G. Lyons.  Fuel properties of short-rotation hardwood coppice sprouts , 1986 .

[37]  P. Hakkila,et al.  The technique of recycling wood and bark ash , 1983 .