| 1. |
- Adamopoulos, Stergios
(författare)
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Identification of Fibre Components in Packaging Grade Papers
- 2006
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Ingår i: IAWA Journal. - : Brill Academic Publishers. - 0928-1541 .- 2294-1932. ; 27:2, s. 153-172
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Tidskriftsartikel (refereegranskat)abstract
- Environmental and economic issues have led to a significant increase of recycled paper as the main fibrous component of corrugated board the last years. Qualitative data on the different fibre types are needed for the evaluation of packaging fibre supply sources, which are becoming numerous and heterogeneous. Fifteen different packaging grade papers (7 linerboards and 8 corrugating medium) were selected to represent all the variety of papers available on the Spanish market. The origin of virgin and recycled fibres was identified by their morphological characteristics employing light microscopy and standard fibre analysis techniques. The waste-based papers (Waste based-liners and Fluting), Kraft-liners and Test-liner were highly variable containing 9–18 different wood and nonwood components. Semi-chemical, with 5–13 components, was the less variable grade. Hardwoods were identified as the most important fibre component from a quantitative standpoint. All papers contained in their hardwood mix Betula, Eucalyptus and Populus in significant amounts. Fagus sylvatica and Tilia were also frequently observed and in some papers were amongst major hardwood components. Prominent softwood components were found to be Pinus sylvestris, P. pinaster, P. radiata, Picea, Larix and in some papers Pinus nigra. The lower presence of a variety of softwood, hardwood and nonwood (mainly grasses) species and genera was due to the paper recycling process.
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| 2. |
- Adamopoulos, Stergios, et al.
(författare)
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Ring width, latewood proportion and density relationships in black locust wood of different origins and clones
- 2010
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 31:2, s. 169-178
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Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional discs were cut at breast height from 19 black locust trees aged 18–39 years of different clones and origin (Greece, Bulgaria and Hungarian clones J, U and NY). Ring width, latewood proportion and dry density were measured according to standard laboratory techniques in order to examine their relationships. Latewood proportion was found to increase (except for one tree from Bulgaria) with increasing ring width and logarithmic equations were calculated with relatively high correlation coefficients. A positive relation between dry density and latewood proportion was found in black locust of Bulgarian origin and in the Hungarian clone NY while in all other cases no meaningful relationship was observed. In mature wood, improved positive linear correlations were observed between dry density and latewood proportion with the exception of the Hungarian clone U. Regression analysis revealed low correlations between dry density and ring width and only black locust from Bulgaria had a high positive correlation. The positive correlations between dry density and ring width were slightly improved in mature wood with the exception of clone J from Hungary.
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| 3. |
- Adamopoulos, Stergios, et al.
(författare)
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Tracheid length – growth relationships of young Pinus brutia grown on reforestation sites
- 2012
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 33:1, s. 39-49
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Tidskriftsartikel (refereegranskat)abstract
- Brutia pine (Pinus brutia Ten.) reforestations have been successfully used for decades in restoration of degraded forest ecosystems in Greece. The future purpose of these reforestations might expand to include wood utilisation. This study provides information on tracheid length of juvenile brutia pine aged 14–22 years grown on good and medium sites in Northeastern Greece. In addition, relationships among ring width, latewood proportion, wood density, and tracheid length were evaluated by using Causal Correlation Analysis. Similar mean tracheid length values were found for good and medium sites. Radial variability of tracheid length was similar on the good and medium sites, showing the typical increase in the juvenile phase. On both site types, latewood proportion showed a strong and positive relationship with wood density. Unexpectedly and only on the good sites, a significant positive relationship was found between ring width and wood density. On the medium sites, tracheid length was negatively related to fast growth and positively to high wood density. Tracheid length on the good sites was correlated only with latewood proportion with a weak positive relationship. The overall results may provide opportunities to better understand the quality of small-dimension timber of brutia pine and to better utilise it.
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| 4. |
- Adamopoulos, Stergios, et al.
(författare)
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Within-tree variation in growth rate and cell dimensions in the wood of black locust (Robinia pseudoacacia)
- 2002
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Ingår i: IAWA Journal. - : Brill Academic Publishers. - 0928-1541 .- 2294-1932. ; 23:2, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- Black locust (Robinia pseudoacacia L.) is regarded as an important natural resource almost throughout the world but relatively little is known about the within-tree variability of the anatomical characteristics of its wood. Discs 2 cm thick were cut at 2.25 m intervals, from the ground level to the top from ten black locust trees, 18–37-years-old, from the University Forest of Taxiarchi, Chalkidiki, Greece. The discs were used for the determination of growth rate and cell dimensions (fiber length and vessel member length and diameter) and their withintree variability (radial, oblique, vertical). Growth rate increased within the first 5–9 growth rings from the pith and then gradually decreased. Oblique variation of growth rate did not exhibit any clear tendency but a decrease at the top. In the case of vertical variation, growth rate decreased gradually with the year of cambium formation. Radial variability curves were found to be typical for the dimensions of cells (fibers, vessel members) especially for the fiber length. A rapid increase in cell dimensions was observed in the first 7–11 growth rings, the juvenile zone. Oblique and vertical variation of cell dimensions did not exhibit any clear tendencies.
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| 5. |
- Adamopoulos, Stergios, et al.
(författare)
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Wood structure and topochemistry of Juniperus excelsa
- 2011
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 32:1, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- Wood structure and topochemical distribution of lignin and phenolic extractives in Juniperus excelsa Bieb. were investigated using a mature specimen, aproximately 80 years of age, from the Rhodope mountains, Greece. The wood of J. excelsa was found to possess the same qualitative anatomical features as those reported for other Juniperus species of the Western Hemisphere. Quantitative anatomical characteristics recorded for mature wood (heartwood and sapwood) included earlywood and latewood tracheid length, double wall thickness of earlywood and latewood tracheids, lumen diameter of earlywood tracheids and ray height. Scanning UV microspectrophotometry revealed a pronounced lignification of J. excelsa tracheids with detected absorbance values of the secondary cell wall layers being much higher in comparison to all other softwoods studied using this technique. The cell corners and compound middle lamellae were characterised by relative high UV absorbance values as compared to the S2 layers. The phenolic compounds deposited in the axial and ray parenchyma cells possessed higher absorbance values than cell wall associated lignins and had a different spectral behaviour due to the presence of chromophoric groups. According to the obtained UV absorbance spectra, more condensed phenolic compounds were deposited in the heartwood than in the sapwood.
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| 6. |
- Cleary, Michelle
(författare)
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FORMATION OF TRAUMATIC RESIN DUCTS IN THE PHLOEM OF WESTERN REDCEDAR (THUJA PLICATA) ROOTS FOLLOWING ABIOTIC INJURY AND PATHOGENIC INVASION BY ARMILLARIA OSTOYAE
- 2011
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 32, s. 351-359
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Tidskriftsartikel (refereegranskat)abstract
- Anatomical changes involved in traumatic phloem resin duct (TPRD) formation in western redcedar (Thuja plicata) roots were examined following abiotic wounding and fungal invasion by Armillaria ostoyae. Following necrophylactic periderm formation, hyperplasia and expansion of a band of phloem parenchyma cells occurred in close proximity to the vascular cambium and schizogenous and lysigenous separation of its derivatives resulted in a series of longitudinal resin ducts in the inner to mid-phloem region. Fungal invasion appeared to amplify traumatic resin duct formation in the phloem. While traumatic cavities in the phloem have been reported for other Cupressaceae, this is the first report documenting TPRD formation in western redcedar.
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| 7. |
- Hafrén, Jonas, et al.
(författare)
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The distribution of acidic and esterified pectin in cambium, developing xylem and mature xylem of Pinus sylvestris
- 2000
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 21:2, s. 157-168
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Tidskriftsartikel (refereegranskat)abstract
- Homogalacturonans with low and high degree of methyl esterification have been immuno-localised in the cambium, differentiating xylem and mature xylem of Pinus sylvestris, by monoclonal antibodies JIM5 and JIM7. In the unlignified cambial tissue the antibodies revealed a similar distribution for acidic and esterified pectin in the compound middle lamella, ray cell walls and pit membranes. In the lignified xylem tissue, pectin was also found in the compound middle lamella, although dominantly in the methylesterified form. Lignification seemed to coincide with a decrease in the presence of acidic pectin in the compound middle lamella. Both antibodies indicated labelling in pit membranes and ray cell walls in partially and fully lignified wood fibres.
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| 8. |
- Kim, Jongsik, et al.
(författare)
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Developmental localization of homogalacturonan and xyloglucan epitopes in pit membranes varies between pit types in two poplar species
- 2013
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 34, s. 245-262
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Tidskriftsartikel (refereegranskat)abstract
- Localization of homogalacturonan (HG) and xyloglucan epitopes in developing and mature pit membranes from different pit types in xylem ofPopulus tremula L. × aspen) was investigated using immunogold labeling. Pit types not mediated byP. tremuloides Michx. (hybrid aspen) and Populus tremula L. (European ray parenchyma (intervessel- and fiber pits) showed significant developmental changes in HG epitope localization. Both low- and high methyl-esterified HG epitopes (recognized by LM19 and LM20, respectively) were detected in de pit membranes of intervessel- and fiber pits until late stages of xylem formation, whereas no HG- and high methyl-esterified HG epitopes were de in mature intervessel (except for annulus regions of pit membranes)- andvelopingtected mature fiber pit membranes, respectively. In contrast, no notable developmental changes in HG epitope localization were detected in pit types mediated by ray parenchyma (vessel-ray-, ray- and fiber-ray pits) during pit maturation. Vesselray- and fiber-ray pits showed abundant low- and high methyl-esterified HG epitopes in pit membranes, while ray pits showed presence of primarily low methyl-esterified HG epitope during all stages of pit development including at maturity. With xyloglucan (recognized by LM15), specific developmental changes in epitope localization were detected in vessel-ray pits. Xyloglucan epitope was detected in developing vessel-ray pit membranes, but was almost absent in mature pit membranes. Instead, xyloglucan was detected in the protective layers of vessel-ray pits showing completely different localization pattern than homogalacturonan, which was only detected in pit membranes. Together, our results suggest that the chemistry of pit membranes varies depending on both the developmental stage and pit type.
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| 9. |
- Kim, Jongsik, et al.
(författare)
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Distribution of lignin, pectins and hemicelluloses in tension wood fibers of European ash (Fraxinus excelsior)
- 2019
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 40, s. 741-764
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Tidskriftsartikel (refereegranskat)abstract
- Although there is considerable information on the chemistry of gelatinous (G) layers in tension wood (TW) fibers consisting of S-1+S-2+G cell wall structure (poplar), little is known on the chemistry of G-layers in TW fibers organized with S-1+G structure. This study investigated the distribution of lignin and noncellulosic polysaccharides in ash TW fibers (S-1+G) using histochemistry and immunolocalization methods. TW fibers studied were fully developed (mature fibers) and obtained from two (TW-1, TW-2) mature European ash trees (Fraxinus excelsior L.). Based on differences in microfibril angle (MFA) and TW trees used, TW fibers were mainly classified into three types; 1) Type-1 fibers with MFA almost parallel to the fiber axis that were found in TW-1, 2) Type-2 fibers with 12 degrees MFA that were abundant at the end of growth rings of TW-1 and 3) Type-3 fibers with 10 degrees MFA that were found in TW-2. The S-3 layer was absent in all TW fibers. In this study, the secondary cell wall structure of Type-1 and Type-2/Type-3 fibers were defined as G and GL (gelatinous-like) layers, respec-tively. Lignin with syringyl (S) units was detected in G/GL-layers, in which intensity and patterns of lignin staining likely related to the difference in MFA between G- and GL-layers. With hemicelluloses, heteroxylan and heteromannan epitopes were detected in G/GL-layers but these were much less abundant than those in S-2 layers of normal wood (NW) fibers. Like lignin, distribution patterns of heteromannan epitopes in G/GL-layers likely related to differences in MFA between fiber types. Sparse xyloglucan epitopes were also detected in G/GL-layers. Homogalacturonan epitopes were absent in G/GL-layers. All fiber types showed abundant a-1,5-arabinan epitopes in G/GL-layers. Overall results indicate that the chemistry of ash TW fibers studied differs significantly from that of other species reported previously, specifically TW fibers composed of S-1+S-2+G structure.
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| 10. |
- Kim, Jongsik, et al.
(författare)
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Distribution of phenolic compounds, pectins and hemicelluloses in mature pit membranes and its variation between pit types in English oak xylem (Quercus robur)
- 2016
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Ingår i: IAWA Journal. - : Brill. - 0928-1541 .- 2294-1932. ; 37, s. 402-419
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Tidskriftsartikel (refereegranskat)abstract
- Although there is considerable information on the chemistry of bordered intervessel pit membranes, little is known on the pit membrane chemistry of other pit types in hardwoods. This study investigated distribution of phenolic compounds, pectins and hemicelluloses in different mature pit membranes of English oak xylem using transmission electron microscopy coupled with cytochemistry and immunocytochemistry. Mature bordered intertracheid (vasicentric)- and tracheid-vessel pits showed presence of xyloglucan and heteromannan (hemicelluloses) epitopes across the pit membrane (except for the annulus regions) with differences in amounts of epitopes between earlywood (EW) and latewood (LW). In contrast, pectin epitopes were detected only in the annulus regions of pit membranes. Unlike bordered pits, half-bordered (tracheary-parenchyma pits) and simple (parenchyma pits) pit membranes were rich in pectin epitopes but lacked heteromannan epitopes, indicating difference in pit membrane chemistry between pit types. Distribution of phenolic compounds also differed between pit types and between EW and LW. LW also showed great variations in distribution of phenolic compounds between vessels. Together, this study demonstrates that there are great variations in pit membrane chemistry between pit types and between EW and LW in English oak xylem..
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