• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.50-56
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• 1998

Thirty-six $F_3$ hybrid poplar (Populus trichocarpa${\times}$P. deltoides) clones were fumigated with ozone to select for ozone sensitive and resistant clones. Fumigation was applied for 6 to 8 hours each day for approximately 3 months at ozone concentrations of 90 to 115 ppb using by open-top chambers. Height, diameter, number of leaves, total biomass, biomass components, root/shoot ratios, leaf drop and stomatal response were investigated. In summary, ozone generally reduced height, diameter, number of leaves, total biomass, and root/shoot ratios. Ozone stress induced leaf drop and foliar senescence in trees. This study showed very low relationship between total biomass and stomatal conductance. Increased plant resistant to ozone is not always correlated with stomatal behaviour. Probably, characterization of biochemical and other physiological responses to ozone exposure can provide a better understanding of tree response to ozone environment.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.57-66
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• 2004

To study the efficient usage of small diameter logs and woods containing defects such as knots, slope of the grain and decay, six types of finger-jointed woods with various finger profiles were made of poplar, pine and oak with different density. We investigated the effect of finger profile on static bending strength performances of finger-jointed woods. The efficiency of bending MOE, MOR and deflection showed the highest value in poplar finger-jointed wood with the lowest density of three species, and the lowest value in oak finger-jointed wood with the highest density of three species. The values markedly decreased with increasing finger pitch for finger-jointed wood glued with polyvinyl acetate (PVAc) resin for all tested species, whereas for the finger-jointed wood glued with resorcinol-phenol formaldehyde (RPF) resin, the influence of finger pitch on the efficiency of MOE was not found in all tested species, and those on the efficiency of MOR and deflection indicated the same trend as finger-jointed wood glued with PVAc resin in the case of pine and oak finger-jointed wood with higher densities. It was found that the values tended to decrease with increasing density of species on the whole and the desirable finger pitches were L (6.8 mm) for poplar, M (4.4 mm) for pine and S (3.5 mm) for oak in a view of economy. For finger-jointed wood glued with PVAc resin, the fitness between a tip and a root width of a pair of fingers δ of 0.5 mm indicated the highest efficiency of MOE for all species. And, the influence of δ on MOR was only found in oak finger-jointed wood glued with RPF resin and the desirable δ value for oak was 0.1 mm. However, it was found that the influence of δ on the strength performance was very small.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.685-694
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• 2016

In this study, the thermal degradation behavior of biomass during torrefaction was studied by thermogravimetric and byproduct gas analysis. Torrefaction temperature, time, and heating rate were $220{\sim}300^{\circ}C$, 110 min, and $10{\sim}30^{\circ}C/min$, respectively. The degradation rate of yellow poplar was 8.01~8.81% at $220^{\circ}C$ and 71.86~77.38% at $300^{\circ}C$ depending on heating rate. The degradation rate significantly increased at temperature over $240^{\circ}C$. On the other hand, degradation rate of larch was relatively low as 49.58~54.15% at $300^{\circ}C$. The activation energy of yellow poplar was 87.32~91.24 kJ/mol; these values did not significantly change with heating rate. The activation energy of larch was 83.85~91.60 kJ/mol. The major components of the gas generated during torrefaction were derived from hemicellulose. The component types and concentrations increased with torrefaction severity. High concentrations of furfural and acetic acid were detected during torrefaction of yellow poplar.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.5
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• pp.37-48
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• 2015

Soil nutrient management is important to maintain the constant productivity of seedling production in the nursery for successful forest restoration. This study investigated the effects of organic manure and chemical fertilizer application levels on the growth, soil properties, and nutrient concentrations of yellow poplar seedlings. One-year-old yellow poplar seedlings were treated with the combination of 3 level organic manures(0, 5 Mg/ha, 10 Mg/ha; mixture of poultry manure, cattle manure, swine manure, and sawdust) and 3 level nitrogen-phosphorus-potassium(NPK) chemical fertilizers(0, 1x(urea, $30g/m^2$; fused superphosphate, $70g/m^2$; potassium chloride, $15g/m^2$), 2x). Organic manure significantly increased the soil pH and the concentrations of nitrogen, available phosphorous, exchangeable potassium, calcium, and magnesium. In contrast, the NPK chemical fertilizer decreased the soil pH and exchangeable calcium concentration, did not affect the soil concentrations of nitrogen and magnesium, and increased the concentrations of available phosphorous and exchangeable potassium. Both organic manure and NPK chemical fertilizer treatments increased the seedling height, root collar diameter, and dry weight by 39% and 25%, respectively. The treatment with manure 5 Mg/ha and NPK 2x chemical fertilizer mostly increased seedling dry weight by 2.6 times more than that of the control. Compared to the effects of the fertilization treatments on the soil properties, the effects on nutrient concentrations in the leaves were relatively small. These findings indicate that organic manure that was derived from livestock byproducts and sawdust can be utilized with chemical fertilizer to improve seedling production as well as conserving soil quality.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.17-23
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• 2011

Growth characteristics and adaptability of 10 poplar clones planted at a reclaimed tidal flat were evaluated. The contents of $Na^+$, $Ca^{2+}$ and $Mg^{2+}$ were 10.0, 3.4 and 1.5 times higher, respectively than those of control although the electrical conductivity(EC) in the soil at the test plantation was low as much as 0.51 dS/m. The contents of organic matter(OM) and total nitrogen(TN) in the soil were 22.9 and 23.0 times lower than those of control. Average survival rate of 10 poplar clones showed 88% at three years after planting. Clones Eco28(Populus euramericana), Dorskamp(Populus deltoides ${\times}$ P. nigra) and I-476(Populus euramericana) showed the best survival rate of 100%. However, clones 97-19(Populus deltoides(Lux) ${\times}$ P. deltoides(Harvard)) and Suwon (Populus koreana ${\times}$ P. nigra var. italica) were relatively lower than other clones. Average height and DBH of all clones were 4.8 m and 3.6 cm, respectively. Clone Dorskamp showed the greatest height and DBH, 5.9 m and 5.0 cm, respectively. Clones 97-19 and Dorskamp showed the least defoliation by stress and visible damage by insects and diseases, whereas clones Suwon and I-476 were the most sensitive at the reclaimed tidal flat. Clone Dorskamp showed the best adaptability at the reclaimed tidal flat, but clone Suwon showed the worst based on survival rate, growth, and visible damages.

• The Korean Journal of Mycology
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• v.11 no.1
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• pp.9-13
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• 1983

Ectomycorrhizal fungi in Pinus $rigida{\times}taeda$ and poplar stands (Populus $alba{\times}glandulosa$ and others) were collected in 1981 and 1982. A total of 39 mushrooms representing 15 genera were identified from the pine stand, and the major genera were Amanita, Lactarius, Russula, Laccaria, and Boletus. From the poplar stands 16 mushrooms representing 8 genera were identified and 13 of them were the same found in the pine stand. Amanita, Russula, Laccaria, and Leccinum are the major genera in the poplar stands. A single species of Boletus was found in large number in pine and poplar stands. Lactarius was not observed in the poplar stands, while Leccinum was not found in the pine stand. Cantharellus lutescens which has not been reported in Korea was collected in the pine stand.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.305-310
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• 2009

Yellow poplar was selected a promising biomass resources for bio-ethanol production through alkali prehydrolysis, enzymatic saccharification and fermentation using commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 mixtures) and fermenting yeast. In alkali prehydrolysis, 51.1% of Yellow poplar biomass remained as residues, which chemical compositions were 82.2% of cellulose, 17.6% of xylan and 2.0% of lignin. In alkali prehydrolysis process, 96.9% of cellulose, 38.0% of xylan and 5.7% of lignin were remained. Enzymatic saccharification by commercial cellulases led to 87.0% of cellulose to glucose and 87.2% of xylan to xylose conversion. Produced glucose and xylose were fermented with fermenting yeast (Saccharomycess cerevisiae), which resulted in selective fermentation of glucose only to bio-ethanol. Residual monosaccharides after fermentation were consisted to 0.4-1.4% of glucose and 92.1-99.5% of xylose. Ethanol concentration was highest for 24 h fermentation as 57.2 g/L, but gradually decreased to 56.2 g/L for 48 h fermentation and 54.3 g/L for 72 h fermentation, due to the ethanol consumption by fermenting yeast.

• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.83-88
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• 2001

A cell culture system of poplar (Populus alba x P.glandulosa) was established to test four different methods for evaluation of cellular stresses. Two different kinds of stresses were given to the cultures by adding either Pb(NO$_3$)$_2$ or paraquat and the cellular responses were monitored during a week period. While fresh weight reduction was observable in two days after the treatment of Pb(NO$_3$)$_2$, such changes were apparent only in later stage in paraquat treated cultures. Cells in paraquat treated cultures in the first 3 days showed no alteration in fresh weight as compared to untreated cultures, but had their MTT reducing activities completely inhibited. Neither Evans blue staining nor ion conductivity of the medium was consistent with fresh weight changes of the cultures. Overall, cell clumps formed during suspension culture appeared to interfere with staining and washing reactions and thus cause the assays unreliable. Among the four methods examined, fresh weight changes and MTT reducing activity appeared to be the most reliable and consistent.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.17-24
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• 2000

The peroxidase activity was localized cytochemically to get an insight into its precise function in lignin biosynthesis. In this work, cerium chloride ($CeCl_3$) was used as a trapping agent for hydrogen peroxide ($H_2O_2$) generated from peroxidase. Seasonal variation of peroxidase activities in cambial region of Populus, Pinus, and Ginkgo was investigated at subcellular levels. Under transmission electron microscopy, electron dense deposits of cerium perhydroxide formed by reaction with $H_2O_2$ were observed in cambium and its immediate derivatives. The staining with $CeCl_3$ in cambium varied with growth seasons. The strongest $H_2O_2$ accumulation, regardless of tree species, appeared in May. Staining pattern of $CeCl_3$ in the cambium of poplar indicated that the production of peroxidase started in March before the opening of buds and reached the highest in May and then declined in August. Ginkgo and Pinus showed relatively late generation of $H_2O_2$ production when compared with Populus. Although Ginkgo and Pinus are classified into gymnosperms, however, the generation of peroxidase production and its duration was different from each other. Little staining appeared in all the tree samples collected in September before falling the leaves.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.44-50
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• 2006

To characterize thermo-chemical feature of su gar conversion of woody biomass poplar wood (Populus alba${\times}$glandulosa ) by sub- and supercritical water was treated for 60s under subcritical (23 MPa, 325 and $350^{\circ}C$) and supercritical (23 MPa, 380, 400, and $425^{\circ}C$) conditions, respectively. Among degradation products undegraded poplar wood solids existed in aqueous products. As the treatment temperature increased, the degradation of poplar wood was enhanced and reached up to 83.1% at $425^{\circ}C$. The monomeric sugars derived from fibers of poplar wood by sub- and supercritical treatment were analyzed by high performance anionic exchange chromatography (HPAEC). Under the subcritical temperature ranges, xylan, main hemicellulose component in poplar wood, was preferentially degraded to xylose, while cellulose degradation started at the transition zone between sub and supercritical conditions and was remarkably accelerated at the supercritical condition. The highest yield of monomeric sugars amounts to ca. 7.3% based on air dried wood weight (MC 10%) at $425^{\circ}C$.