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C L Mohammed - One of the best experts on this subject based on the ideXlab platform.
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identification of hydrolysable tannins in the reaction zone of eucalyptus nitens wood by high performance liquid chromatography electrospray ionisation mass spectrometry
Phytochemical Analysis, 2001Co-Authors: K M Barry, C L Mohammed, Noel W. DaviesAbstract:The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the Sapwood of a Eucalyptus spp. is presented. Plantation-grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy Sapwood and from reaction zone tissue. Analysis by HPLC with ESI-MS revealed that a diverse range of hydrolysable tannins are present in both healthy Sapwood and in reaction zone extracts, including over 30 gallotannins, ellagitannins and phenols. Eight tannins were unequivocally identified, including the gallotannins tri-O-galloyl-β-D-glucose, tetra-O-galloyl-β-D-glucose and penta-O-galloyl-β-D-glucose, and the ellagitannins pedunculagin, tellimagrandin I, casuarinin, casuarictin and tellimagrandin II. The phenols gallic acid, ellagic acid and catechin were also identified. The ellagitannins (particularly pedunculagin) are considerably more abundant in the reaction zone than in the healthy Sapwood and may contribute to the effectiveness of the reaction zone as an antimicrobial barrier.
Mark E Harmon - One of the best experts on this subject based on the ideXlab platform.
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Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon
Oecologia, 2003Co-Authors: Michele L Pruyn, Mark E Harmon, B. L. GartnerAbstract:Mature and old growth trees of varying Sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), Sapwood, and heartwood thickness measurements were used to predict Sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of Sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow Sapwood (8–16% of bole radius) such as Pseudotusga menziesii , Taxus brevifolia , and Thuja plicata , had Sapwood respiratory potentials in the lower bole that were 50% higher ( P 16% of bole radius), such as Abies amabilis , Pinus monticola , and Tsuga heterophylla . This pattern was not observed for inner bark respiratory potential, or for Sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus Sapwood divided by whole bole volume) (Adj. R ^2=0.6). Specifically, tree species with 18–20% of the main bole alive potentially respired 1.3–3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of Sapwood.
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respiratory potential in Sapwood of old versus young ponderosa pine trees in the pacific northwest
Tree Physiology, 2002Co-Authors: Michele L Pruyn, Barbara L Gartner, Mark E HarmonAbstract:: Our primary objective was to present and test a new technique for in vitro estimation of respiration of cores taken from old trees to determine respiratory trends in Sapwood. Our secondary objective was to quantify effects of tree age and stem position on respiratory potential (rate of CO2 production of woody tissue under standardized laboratory conditions). We extracted cores from one to four vertical positions in boles of +200-, +50- and +15-year-old Pinus ponderosa Dougl. ex Laws. trees. Cores were divided into five segments corresponding to radial depths of inner bark; outer, middle and inner Sapwood; and heartwood. Data suggested that core segment CO2 production was an indicator of its respiratory activity, and that potential artifacts caused by wounding and extraction were minimal. On a dry mass basis, respiratory potential of inner bark was 3-15 times greater than that of Sapwood at all heights for all ages (P < 0.0001). Within Sapwood at all heights and in all ages of trees, outer Sapwood had a 30-60% higher respiratory potential than middle or inner Sapwood (P < 0.005). Heartwood had only 2-10% of the respiratory potential of outer Sapwood. For all ages of trees, Sapwood rings produced in the same calendar year released over 50% more CO2 at treetops than at bases (P < 0.0001). When scaled to the whole-tree level on a Sapwood volume basis, Sapwood of younger trees had higher respiratory potential than Sapwood of older trees. In contrast, the trend was reversed when using the outer-bark surface area of stems as a basis for comparing respiratory potential. The differences observed in respiratory potential calculated on a core dry mass, Sapwood volume, or outer-bark surface area basis clearly demonstrate that the resulting trends within and among trees are determined by the way in which the data are expressed. Although these data are based on core segments rather than in vivo measurements, we conclude that the relative differences are probably valid even if the absolute differences are not.
Michele L Pruyn - One of the best experts on this subject based on the ideXlab platform.
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Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon
Oecologia, 2003Co-Authors: Michele L Pruyn, Mark E Harmon, B. L. GartnerAbstract:Mature and old growth trees of varying Sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), Sapwood, and heartwood thickness measurements were used to predict Sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of Sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow Sapwood (8–16% of bole radius) such as Pseudotusga menziesii , Taxus brevifolia , and Thuja plicata , had Sapwood respiratory potentials in the lower bole that were 50% higher ( P 16% of bole radius), such as Abies amabilis , Pinus monticola , and Tsuga heterophylla . This pattern was not observed for inner bark respiratory potential, or for Sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus Sapwood divided by whole bole volume) (Adj. R ^2=0.6). Specifically, tree species with 18–20% of the main bole alive potentially respired 1.3–3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of Sapwood.
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respiratory potential in Sapwood of old versus young ponderosa pine trees in the pacific northwest
Tree Physiology, 2002Co-Authors: Michele L Pruyn, Barbara L Gartner, Mark E HarmonAbstract:: Our primary objective was to present and test a new technique for in vitro estimation of respiration of cores taken from old trees to determine respiratory trends in Sapwood. Our secondary objective was to quantify effects of tree age and stem position on respiratory potential (rate of CO2 production of woody tissue under standardized laboratory conditions). We extracted cores from one to four vertical positions in boles of +200-, +50- and +15-year-old Pinus ponderosa Dougl. ex Laws. trees. Cores were divided into five segments corresponding to radial depths of inner bark; outer, middle and inner Sapwood; and heartwood. Data suggested that core segment CO2 production was an indicator of its respiratory activity, and that potential artifacts caused by wounding and extraction were minimal. On a dry mass basis, respiratory potential of inner bark was 3-15 times greater than that of Sapwood at all heights for all ages (P < 0.0001). Within Sapwood at all heights and in all ages of trees, outer Sapwood had a 30-60% higher respiratory potential than middle or inner Sapwood (P < 0.005). Heartwood had only 2-10% of the respiratory potential of outer Sapwood. For all ages of trees, Sapwood rings produced in the same calendar year released over 50% more CO2 at treetops than at bases (P < 0.0001). When scaled to the whole-tree level on a Sapwood volume basis, Sapwood of younger trees had higher respiratory potential than Sapwood of older trees. In contrast, the trend was reversed when using the outer-bark surface area of stems as a basis for comparing respiratory potential. The differences observed in respiratory potential calculated on a core dry mass, Sapwood volume, or outer-bark surface area basis clearly demonstrate that the resulting trends within and among trees are determined by the way in which the data are expressed. Although these data are based on core segments rather than in vivo measurements, we conclude that the relative differences are probably valid even if the absolute differences are not.
Karin Sandberg - One of the best experts on this subject based on the ideXlab platform.
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separating norway spruce heartwood and Sapwood in dried condition with near infrared spectroscopy and multivariate data analysis
European Journal of Forest Research, 2009Co-Authors: Karin Sandberg, Magdalena SterleyAbstract:Norway spruce [Picea abies (L.) Karst.] heartwood and Sapwood have differing wood properties, but are similar in appearance. An investigation was made to see whether near-infrared spectroscopy (NIRS) could be used with multivariate statistics for separation between heartwood and Sapwood in dry state on tangential longitudinal surfaces. For classification of wood into Sapwood and heartwood, partial least square (PLS) regression was used. Orthogonal signal correction (OSC) filtering was used on the spectra. This study shows that a separation of Sapwood and heartwood of spruce is possible with NIR spectra measured in a laboratory environment. The visible-wavelength spectra have significant influence on the predictive power of separation models between Sapwood and heartwood of spruce. All 44 specimens in the calibration set were correctly classified into heartwood and Sapwood. Validation of the model was done with a prediction set of 16 specimens, of which one was classified incorrectly.
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degradation of norway spruce picea abies heartwood and Sapwood during 5 5 years above ground exposure
Wood Material Science and Engineering, 2008Co-Authors: Karin SandbergAbstract:Abstract Differences in durability between heartwood and Sapwood of Norway spruce [Picea abies (L.) Karst.] were investigated to determine wood qualities most favourable for use in outdoor constructions above ground. Trees grown on sites with either good or poor access to water were used. Seventy-eight specimens measuring 20 × 50 × 300 mm3 separated into heartwood and Sapwood, half untreated, half painted, were exposed horizontally outdoors above ground for 5.5 years with the pith side up and the bark side down. Crack length and crack number were measured. Fungus growth and surface changes were visually estimated. Fungus type was determined by microscopic analysis. The main finding was that spruce heartwood had fewer and shorter cracks and less surface-discolouring fungus growth than Sapwood. This was valid for both painted and untreated wood. After 2 years’ exposure, the cracks in Sapwood (upper surface) were more than three times longer and about five times more numerous than in heartwood for both paint...
K M Barry - One of the best experts on this subject based on the ideXlab platform.
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identification of hydrolysable tannins in the reaction zone of eucalyptus nitens wood by high performance liquid chromatography electrospray ionisation mass spectrometry
Phytochemical Analysis, 2001Co-Authors: K M Barry, C L Mohammed, Noel W. DaviesAbstract:The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the Sapwood of a Eucalyptus spp. is presented. Plantation-grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy Sapwood and from reaction zone tissue. Analysis by HPLC with ESI-MS revealed that a diverse range of hydrolysable tannins are present in both healthy Sapwood and in reaction zone extracts, including over 30 gallotannins, ellagitannins and phenols. Eight tannins were unequivocally identified, including the gallotannins tri-O-galloyl-β-D-glucose, tetra-O-galloyl-β-D-glucose and penta-O-galloyl-β-D-glucose, and the ellagitannins pedunculagin, tellimagrandin I, casuarinin, casuarictin and tellimagrandin II. The phenols gallic acid, ellagic acid and catechin were also identified. The ellagitannins (particularly pedunculagin) are considerably more abundant in the reaction zone than in the healthy Sapwood and may contribute to the effectiveness of the reaction zone as an antimicrobial barrier.
