• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.327-338
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• 2014

Relationship between growth rate and wood quality was investigated by physical and mechanical properties with Quercus rubra (24 years old) from five different origin of apricot. In greenwood moisture content, sapwood had higher moisture content than heartwood, and there was difference among different origin of apricot. There were different specific gravity of wood among different origin of apricot. Compared with higher growth rate with higher specific gravity in sapwood, opposite trend was observed in heartwood. There were difference in shrinkage based on origin of apricot, and higher growth rate wood had higher shrinkage and T/R ratio. Compression Young's modulus, bending strength, bending Young's modulus, and compact strength was difference among different origin of apricot. Higher growth rate wood had higher tensile strength, and also there was difference amont different origin of apricot. In hardness, 3 different directions had all difference among different origin of apricot, and higher growth rate wood showed higher hardness than others. Based on overall physical and/or mechanical properties and growth rate, apricot from Bancroft was best quality in current.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.96-108
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• 1982

Pinus is one of the most important species supplying domestic industrial timbers such as constitutional lumber, pulpwood, and mine props. It occupies nearly 50 percent of the total forest resources in Korea. With above conception, to develop this forest resources and to obtain the basic data on the reasonable and effective utilization of Pinus, this study was carried out. Five species (P. koraiensis S. et Z., P. densiflora S. et Z., P. thunbergii Parlat, P. densiflara far erecta, P. rigida Miller) grown in Kwangnoong experimental forest stand, Chungcheongnam-Do, and Gangwon-Do regions were selected as sample trees. Anatomical, physical, mechanical and chemical properties of them were investigated.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.525-534
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• 2017

The study aims to observe the cellular anatomical properties of Dahurian larch and Japanese larch for the species identification. In addition, other factors - the ring width, tracheid length, density, and strength - were compared and analyzed to clarify their physical and mechanical properties. To the end, three Dahurian larch trees and three Japanese larch trees by each diameter class were collected as specimens from Jeongseon-eup, Jeongseon-gun, Gangwon-do, to conduct a stem analysis. It was found that the average stand age, average diameter at breast height, and average tree height of three Dahurian larch trees and Japanese larch trees were 74 years and 51 years, 442 mm and 352 mm, and 26.1 m and 20.8 m, respectively. The cellular anatomical difference between Dahurian larch and Japanese larch can be usually found by spiral thickening, considering that it doesn't occur in Dahurian larch at all, while rarely does in the ray tracheids of Japanese larch. However, in this study, spiral thickening was not observed in the radial section of Japanese larch. The average annual growth diameters measured at 1.2 m-height of Dahurian larch and Japanese larch were 5.167 mm and 5.954 mm, respectively. Meanwhile, arboreal growth of Japanese larch was observed to be higher than that of Dahurian larch. In the physical properties test, it was measured that the latewood proportion and oven-dry density of Dahurian larch with low annual diameter growth were higher than those of Japanese larch, while the mechanical properties of Dahurian larch wood were measured 2-7% higher than those of Japanese larch wood. The data obtained from this study are expected to be used as the basic reference for species identification between Dahurian larch and Japanese larch by DNA analysis.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.237-245
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• 2006

Changes of the biomass, net primary productivity and P/B ratio during abandoned field succession after shifting cultivation were investigated in Pyoungchang, Gangwon-Do, Korea. Aboveground standing biomass of herb species showed the maximum value (3.8 ton/ha) in the 5 year old-field, and decreased thereafter. Litter dry weight was depicted as a parabola form showing the gradual increment during the first 50 years and slight decrease thereafter. Basal area tended to increase logarithmically during abandoned field succession. Tree density showed the gradual increment during the first 15 years and decreased thereafter by the self-thinning process. In the later successional stage (80 years old-field), the shoot density distribution of the tree species by DBH class showed the reverse J shaped curve and Quercus mongolica dominated. Total standing biomass increased slowly in the earlier successional stages and later successional stages, and increased rapidly during the mid-successional stages ($10{\sim}50$ years old-field). Total standing biomass in the 5, 10, 20, 50 and 80 years old-fields were estimated 5, 14, 75, 251 and 373 ton/ha, respectively. Annual net primary productivity were depicted as a parabola form showing the gradual increment during the first 35 years and declined thereafter. The increment rates of the annual net primary productivity in the earlier successional stages showed the higher value than mid-successional stages. The annual net primary productivities in the 5, 10, 20, 35, 50 and 80 years old-field were estimated 8.6, 9.3, 12.9, 15.1, 13.7 and 3.6 ton/ha/yr, respectively. The estimated P/B ratio tended to decrease exponentially during abandoned field succession. The estimated P/B ratio in the 5, 10, 20, 50 and 80 years old-field were 0.60, 0.39, 0.19, 0.06 and 0.01, respectively. These results were fairly in accordance with the bioenergetics model during the forest succession projected by Odum(1969).