• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.344-353
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• 2002

To investigate the forest structure and to suggest the basic data of forest in the Cheongoksan and near the ridge area, the Baekdudaegan, thirty-five plots were set up and surveyed. According to the analysis of classification by TWINSPAN, the community was divined by four groups of Quercus mongolica-Fraxinus rhynchophylla(I). Q. mongolica-Acer pseudosieboldianum(II). Q. mongolica-Tripterygium regelii(III), and Q. mongolica-Rhododendron schlippenbachii community(IV). The structure of communities were investigated using importance value by layer. The survey results were summarized as follows:1) the results of annual ring analysis revealed that the age of forest in the Cheongoksan was about 30~150 years old, 2) number of the average species was 6.5$\pm$1.8 and number of average individuals was 68.3$\pm$39.9 per a plot(100$m^2$). From the above results, it was anticipated that Q. mongolica stand will be old-growth forest because they do not have competitor species and a specific ridge environment.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.565-577
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• 2019

The purpose of this study was to understand the factors influencing the decline and the patterns of changes in Abies nephrolepis populations on Mt. Seorak. We installed permanent quadrats in the areas of the Gwittagicheongbong (peak), Gwanmoneungseon (ridge), and the Seorak Falls and have monitored the community structure, population dynamics, radial growth, and vitality in the quadrats since 2009. Excluding the Seorak Falls, the three research sites showed a three-layer structure in which the low-tree layer forms the canopy. Major tree species were Khingan fir, Korean arborvitae, Mongolian oak, Erman's birch, and Korean maple. The significance of Khingan fir in Seorak Falls decreased from 45.3% in 2009 to 36.8% in 2018. The number of shoots ($DBH{\geq}5cm$) was highest at 1,800 individuals/ha and 1,700 individuals/ha at the Gwittagicheongbong 2 and the Gwanmoneungseon, respectively. The mortality rates over the past 10 years were very high, at 38.3% and 35.3%, respectively, in the Gwittagicheongbong 1 and Seorak Falls. The most stable inverse J-shaped distribution in the Gwittagicheongbong 1 area was shown in the size-frequency distribution of the Khingan fir populations. The average annual ring growth of the Khingan fir was 0.96 ~ 1.73 mm/year, and the ring growth tended to decrease in the areas of Gwittagicheongbong 1, Gwanmoneungseon, and Seorak Falls, where the vitality was low. If the monitoring process continues, it will be possible to obtain basic data for the conservation and management of subalpine vegetation.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.408-423
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• 2021

We established and monitored survey sites in seven regions of Mt. Jiri to investigate population decline and change of the Korean fir (Abies koreana) over a ten-year period from 2009 to 2018. With the exception of one site (Seseok), the six remaining ones all showed a four-layer stratification structure. The importance value of Korean firs in all of the survey areas decreased significantly by 28.5%, from 55.7% in 2009 to 39.8% in 2018. The average population of objects with a diameter at breast height (DBH) of 5cm or more in all survey sites was 711 objects/ha in 2018, and the cumulative death rate from 2009 to 2018 was 10.8%. Among the death types, DS (dead standing) was the most dominant, comprising 82.4% of the total survey area. However, in Banyabong 1, which had a high gradient of 35°, the death types other than DS accounted for 44.2%. We estimate that A. koreana can maintain a stable population as its distribution type for each diameter class in the Saeseokpyeongjeon site showed a reverse-J shape. The average annual ring growth in all survey sites was 1.09 mm/year, with the most abundant growth observed in the Seseokpyeongjeon site, which was formed mainly by a subtree layer. The growth ring survey showed the estimated average age of A. koreana population in the Byeoksoryeong and Banyabong 1 sites to be 102 and 91 years, respectively, a general downward trend of vitality since 2013.

• The Korean Journal of Ecology
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• v.1 no.2
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• pp.66-71
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• 1977

The growth of red and black pines in Muan, Seochen, Gapyeong and Kochang areas was compared by means of the growth of annual ring width and stem analysis to study the process of damages caused by pine needle gall midge. Red pine forest of Seocheon area began to suffer by pine needle gall midge from 1961 and the damage was to becoming severe from 1967. The damage became so intense tha tmany forests are withering to death from spring of 1975. Black pine forest also began to suffer from 1973. Red pine forest of Muan area was supposed to be suffered from 1973. Red pine forest of Kochang area suffered by pine needle gall midge from 1967. It seems that the damage became severe from 1973 and that black pine forest was also badly damaged from that time. Red pine forest of the control plot, Gapyeong area, began to suffer from 1967 and it also became intense from 1973. Although the areas of Seocheon, Muan, Kochang, and Gapyeong are different from each other in terms of locality and the infitration period of pine needle gall equally from 1967 due to mass development of population or other factors and the damage became more intense from 1973. Black pine forest was also badly damaged from that time. Black pine seems to be stronger in insect resistant than red pine. This can be justified by the fact that it began to suffer belatedly in each area and the degree of damage is moderate. The damage of Seocheon area is the severest following Kochang. Muan area is relatively moderate but the forest becoming decrease in growth.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.577-588
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• 1998

Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion and, in urban area atmosphere, are mainly traffic or heating in origin. Size-segregated aerosol samples were collected on the Eixth story of Shinchon on the Yonsei campus, using a high-volume cascade impactor, between August 1994 and September 1995. Ten PAHs were analyzed by GC/MSD. The size distribution of PAH-containing particulates followed approximately a log-normal relationship with the majority of PAH content associated with particles below 3.0mm. PAHs concentration in submicron particles increased during the winter months. The Mass Median Diameter (MMD) value of annual particulates in the heavy traffic area of Shinchon shows about 1.6 pm. The MMD values of air particulate in winter were the lowest values and similar to that in summer, while MMD values of seasonal PAHs were generally lower than 1.0 pm. Among the PAHs, MMD values of PAHs with the more than 5 benzen ring were averagely lower than those with 4 benzin rings. Especially MMD's of dibenzo (a, h) anthracene in winter was clearly lower than in summer. This reason may be caused by fuels used for heating. In this area, 50∼80% PAHs mass was particles smaller than 1.0mm aerodynamic diameter in size range, and the MMD values of PAHs lower than those of other country's area.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.429-437
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• 1999

Heavy metals(Cd, Cu, Pb and Zn) in tree rings of P. thunbergii growing at Onsan Industrial Complex of air polluted area were analyzed to study the condition of heavy metal pollution. The tree ring width began to decrease after operation of factories and decreased abruptly at Onsan Industrial Complex after 1991. Cd contents in tree rings showed 119.4ppb to 867.0ppb level and suddenly increased after 1991. Cu contents showed 309.5ppb to 3686.8ppb, and Pb contents 911.33ppb to 7997.1ppb and fluctuations of those were high after operation of factories. Zn contents showed the highest level of 3528.7ppb to 23826.7ppb and largely ascended after 1960, and increased suddenly after 1992, as compared to former tendency. On the other hand, heavy metal contents in tree rings of P. thunbergii at Gosung of non-air polluted area were far lower than Onsan I. C., and there was a wide difference between both areas after 1990. On the heavy metal contents accumulated in bark of P. thunbergii of both areas, it was higher to 10 times in Cd, 1,000 times in Cu, 285 times in Pb and 133 times in Zn contents at Onsan than at Gosung. In the heavy metal analysis for circle plate and cores, heavy metal contents in cores were generally higher than those in disk and Pb contents showed specially high difference, but pattern of variation by tree age showed a similar tendency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.929-939
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• 2015

We studied the characteristics of age and growth of the Goldeyes rockfish Sebasetes thompsoni in the Ulleungdo and Dokdo areas by using 730 otoliths from February 2013 to February 2014. The lowest value of the marginal index was found in June once a year. The spawning period was estimated as April. Therefore, the duration from fertilization to the complete formation of the first annual growth ring is fourteen months. From the parameters calculated using the weighted average length of the year ring formation, the growth of S. thompsoni was demonstrated by the von Bertalanffy growth equation as $L_t=34.68(1-e^{-0.2113(t+0.7683)})$ for females and $L_t=29.79(1-e^{-0.2163(t+1.7964)})$ for males, $L_t=32.84(1-e^{-0.25(t+0.57)})$ for combined sex. Comparing with growth performance index(${\Phi}$) from these 4 offshore areas, parameter of S. thompsoni in Ulleungdo area was 2.4087, that of in Tong-yeong was 2.2835, that of in Aomori was 2.4077 and in Niigata was 2.3927. As a result, the value of Dokdo and Ulleungdo areas showed the highest.

• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.369-378
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• 2002

To investigate the forest structure and to suggest the basic data of forest in the Baekcheon Valley, fifty plots were set up and surveyed According to the analysis of classification by TWINSPAN. the community was divided by five groups of Quercus mongolica-Pinus densiflora(I), P. densiflora-Q. mongolica(II), Acer pseudosieboldianum-Q. mongolica(III). Betula schmidtii-A. pseudosieboldianum(IV), and Cornus controversa community(V). The structure of communities was investigated using importance value by layers The survey results were summarized as follows: 1) the results of annual ring analysis revealed that the age of Pinus densiflora forest was about 50~75 years old and Q. mongolica forest was about 40 years. 2) number of the average species was 11 1$\pm$2.2 and number of average individual was 74.6$\pm$28 1 per a plot(100$m^2$). From the above results including DBH distribution analysis it was anticipated that the deciduous broad leaf tree like C. controversa and B. schmidtii will be climax species instead of Q. mongolica. and P. densiflora.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.1-13
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• 1987

This study was carried out to investigate the variations of dimension and exterior shape of vessel elements, morphology of spiral thickening and ray-vessel pit in korean diffuse-porous woods (56 species, 18 families), The tangential pore diameter and vessel element length was increased, whereas the pore number per unit area($1mm^2$) was decreased from pith outwards. The tangential pore diameter was decreased but the length of vessel element was not changed from earlywood to latewood within an annual ring. However, the dimensional variations of vessel element was not able to be recognized among relative positions in peripheral variation. The exterior shape of vessel element could be classified into four types; Type 1 is without tail, Type 2 with ligulate tail, Type 3 with broad taper tail and Type 4 with the very short length between perforations. The distribution frequency of Type 2 and 3 was relatively high in comparision with the others. According to the prominence, distribution position and branched shape, the spiral thickenings could be divided into five types. The spiral thickenings occurred 52% in the species observed. Thus it was doubtful to consider the simple presence of spiral thickening as diagnostic index in diffuse-porous woods. The morphology of ray-vessel pit could be grouped as reticulate, scalariform, oval, linear and coalescent type. Most of species examined showed oval and linear type.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.189-197
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• 2008

In order to develop the sustainable ecological management, short-necked clams, Ruditapes philippinarum, were collected from Yoengi coast in Tongyoeng, Korea. The growth of the clam was estimated as: $L_f=68.08{\cdot}(1-e^{-0.145(t+0.324)})$ from ring radius composition of shell. Instantaneous co-efficiency of total mortality and natural mortality were calculated as: 0.991/year and 0.494/year, respectively. The age of the clams from the first capture was estimated to be 3.28. The total biomass was estimated to be 212 MT in the fisheries area (6.4 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit were calculated to be 649.5 individual/$m^2$ and $0.7\;g/m^2$, respectively. The current fishing intensity was much lower for maximum sustainable yield and acceptable biological catch. Although higher yield per recruit could be achieved by increasing fishing intensity, it is favorable to retain the current fishing intensity because of the unique fishing attitude on Yeongi coast in Tongyoeng, Korea.