• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.166-177
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• 1988

To investigate the structure of the plant community of the Naejang Temple District in Mt. Naejang National Park, 22 plots were set up by the vegetation physiognomy and vegetation analysis by four kinds of ordination techniques(PO, PCA, RA and DCA) was carried out. Pure and mixed forest community of Quercus variabilis and Q. mongolica were major forest communities and each of them covered 31.27 and 20.77%, respectively. The degree of human disturbance of vegetation 9, 8, 7 and 6 area covered 30.9, 67.0, 0 and 0.02%, respectively. According to stand dynamic analysis by DBH class distribution, the present Pinus densiflora and Quercus communities may be succeeded to Carpinus laxiflora communities. DCA was the most effective method of this study. DCA ordination showed that successional trends of tree species seem to be from P. densiflora through Q. variabilis, Q. aliena, Sorbus alnifolia, Platycarya strobilacea to Carpinus laxiflora, Fraxinus rhynchophylla, Zelkova serrata, Cornus controversa in the tree layer, and from Rhododendron mucronulatum, Rh. schlippenbachii, Lespedeza cyrtobotrya, Rhus trichocarpa through Styrax japonica, Daphniphyllum macropodum, Sapium japonicum to Euonymus oxyphyllum, E. sieboldiana, Lindera erythrocarpa in the subtree layer.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.31-42
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• 1990

Storage ecosystems of rough rice, brown rice and polished rice were analyzed form Feb. 1987 to Nov. 1988 to investigate structures and ecological successions in the arthropod communities as well as changes in energy of the systems. The changes in temperature of stored rice showed high degree dependence on the temperature of storage room with time lag of about four weeks. Moisture content of rough rice, brown rice and polished rice during the period were in the range of 12.7$\pm$0.4, 13.1$\pm$0.4 and 13.5$\pm$0.3%, respectively. The arthropod communities in rough rice, brown rice and polished rice were qualitatively and quantitatively different. In rough rice, dominant species changed from Leptinotus reticulatus Endlein to Liposcelisentomophilus Endlein, while in brown rice from Pyralis farinalis L. to Sitophilus oryze (L.), unidentified parasitic wasps, Anisopteromalus calandrae Howard and Tribolium castaneum Herbst and finally to S. oryzae. In polished rice, the arthropod community showed an ecological succession similar to that in brown rice except for a transient dominance of two psocidspecies. Thearthropod community in rough rice was rather simple and unstable in comparison with those in brown rice and polished rice. The 1000 kernel weight of brown rice decreased slightly during the period when the arthropods were active (summer season), while that of rough rice and polished rice remained at the similar level. However, the ash content per unit volume of brown rice as well as rough rice and polished rice showed no increase during the period.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.222-228
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• 2012

This study was conducted to determine the natural succession process after forest fire by comparing height, relative growth rates in height (RGH), and tree density of pine seedlings with different fire severity. In the area damaged by surface fire, tree density was highest during the first 5 years after fire. However, in the area damaged by crown fire, tree density rapidly increased during first 5 years after fire. Pine seedlings were found only on the place with ridges, barren soil, and the aspect of north. Annual height growth of pine seedlings was decreased with time in all study sites. The empty space in pine stands gradually decreased by the invasion of Quercus species. The forest fire altered the pine forest into oak forest rapidly. In contrast, pine seedlings invaded steadily on the oak forest in the rocky area or the area with ridges.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.342-351
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• 1999

The forest vegetation developing on Mt. Inwang, an isolated forestland in Seoul, Korea was analyzed phytosociologically and its spatial distribution mapped out. Using the vegetation map, The characteristics of landscape structures in terms of the number and size of patches are discussed. Forest vegetation of the study area was classified into ten communities, ten groups, and eighty subgroups. Landscape element types were classified into secondary forests, relict communities, introduced plantations, and other elements including urbanized area. Pinus densiflora community, natural forest and Robinia pseudo-acacia community, plantation, formed matrix and some secondary forest elements, relict communities and the ether plantations of small size tended to distribute as small patches in such matrix. The number of patches per unit area in secondary forest elements was more than that in plantation elements. The result in patch size was vice versa. The vascular plant species richness of the landscape element types in Mt. Inwang was found to he positively related to their size. As the results of landscape ecological analyses, it was estimated that differentiation of patches recognized in community level would be related to human interference a and those in subordinate levels to natural process such as progression of succession.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.631-639
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• 2017

The relationship between the environmental factors (water temperature, salinity, chlorophyll-a concentration, Noctiluca scintillans density, Diatoms and Dinoflagellates densities) and the zooplankton community was investigated. Zooplankton were seasonally collected at 11 stations of Gwangyang Bay from November 2015 to July 2016. A mean abundance ranged from 544 to $19,753indiv.\;m^{-3}$. The maximum abundance was observed to be $40,000indiv.\;m^{-3}$ in July and the minimum occurred in November with $412indiv.\;m^{-3}$. The zooplankton consisted of 35 taxa, which is dominated by Paracalanus parvus s. l., Corycaeus spp., Oithona spp., Acartia omorii, A. ohtsukai, Centropages abdominalis, unidentified harpacticoids. The result of the Redundancy Analysis (RDA) conducted between the zooplankton and the environmental factors showed that the spring-autumn, summer and winter are separated. The summer was closely related to temperature and diatom density, while the winter was linked to salinity and N. scintillans density (p<0.05).

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.237-255
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• 2021

Lychnis wilfordii (Regel) Maxim. is one of the wetland specialists mainly distributed in peatlands at high latitudes. In Korea, it is isolated in two regions. This study investigated habitats, growth traits, and self-compatibility of L. wilfordii and assessed the internal dynamics of its population persistence. Its population has remained stable in the Yongneup Wetland Protected Area (YWPA). There was a clear difference in vegetation environment between YWPA and the distribution area in Daegwallyeong (DWL), Pyeongchang-gun. It has self-compatibility while pollinators facilitate its seed production. It produces a large number of hibernacles and bears the maximum number of branches and fruits in soil with rich organic contents. However, it grows and bears fruits even under the condition of low organic contents. In YWPA, L. wilfordii is not distributed in high moor but widely distributed in low moor where tussocks by Carex thunbergii var. appendiculata are developed. It is mainly distributed on the top of tussocks also. Therefore, it is judged that the formation, growth, and extinction of tussocks by C. thunbergii var. appendiculata is closely related to the establishment, growth, and extinction of plants distributed in this space. It is assessed that the current YWPA has well-developed tussocks in which L. wilfordii is widely distributed, and extinction and re-establishment progress well. Accordingly, the L. wilfordii population is expected to be sustainable in the long term given if its current ecological process is maintained well.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.412-425
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• 2012

This study investigated the actual vegetation and plant community structure of Geumsun valley and Weonjeok valley of Naejangsan(Mt.) National Park to provide the data for park management. As a result of analysis of actual vegetation, Quercus variabilis community(47.3%) and Quercus serrata community(17.0%) are widely distributed but Carpinus tschonoskii community(7.5%) and Zelkova serrata community(6.9%) are distributed in valley forests. Plant communities were divided into 6 communities of Fraxinus mandshurica, Carpinus tschonoskii, Carpinus tschonoskii-Platycarya strobilacea-Zelkova serrata, Zelkova serrata, deciduous broad-leaved mixture(Zelkova serrata-Lindera erythrocarpa-Acer palmatum), and Lindera erythrocarpa-Cornus walteri according to the analysis of TWINSPAN of classification using 20 plots($400m^2$). Geumseon valley is composed of boulder stone area of average slope $20^{\circ}$, and there were distributed Fraxinus mandshurica community of 86 years old, Carpinus tschonoskii community in age from 56 to 79, and Carpinus tschonoskii-Platycarya strobilacea-Zelkova serrata community in age from 48 to 71. Weonjeok valley is composed of boulder stone area of average slope $11^{\circ}$, and there were distributed Zelkova serrata community in age from 52 to 71, deciduous broad-leaved mixture community in age from 49 to 70, and Lindera erythrocarpa-Cornus walteri community in age from 43 to 51. Ecological succession of each community was predicted to maintain same state. The Shannon's species diversity showed from 0.8220(Fraxinus mandshurica community) to 1.3850(Carpinus tschonoskii community) per unit area of $400m^2$.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.223-232
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• 1997

One hundred Sixty two quadrats were sampled from natural forests, in Kangwon-do and Kyungsangbuk-do. On the basis of Mueller-Dombois & Ellenberg method, field survey, which accounts for the characters of the species structure of Pinus densiflora community and Quercus mongolica community, was carried out between 1991 and 1994. To analyze the data, CCA ordination and D.B.H, analysis were used. 1. DBH analysis showed that Pinus densiflora community is likely replacing Quercus mongolica or Quercus variabilis community. DBH analysis also showed that Quercus mongolica - Lindera obtusiloba community balances among the Quercus mongolica, Fraxinus rhynchophylla, and Tilia amurensid in the canopy, and that Quercus mongolica-Abies nephrolepis community, mixed forest balances among the Quercus mongolica, Pinus koraiensis, and Abies nephrolepis in the canopy. In general, Quercus mongolica seems to remain as a dominant species. 2. A certain correlation seems to exist between nutrients types and Pinus densiflora community. Quercus mongolica prefered to grow in the medium elevation area that has medium level of total nitrogen, organic matter, and C.E.C. Pinus densiflora, Quercus serrata and Quercus variabilis were found in the low elevation area that has low level of total nitrogen, organic matter, and C.E.C. 3. There seemed to be a certain correlation between nutrients types and Quercus mongolica community. Quercus mongolica and Acer pseudosieboldianum was distributed in the slope area that has medium level of $Mg^{{+}{+}}$, $Ca^{{+}{+}}$, and C.E.C., while Abies nephrolepis, Taxus cuspidata and Pinus koraiensis in the high elevation and ridge area that has low level of $Mg^{{+}{+}}$, $Ca^{{+}{+}}$, and C.E.C. Carpinus laxiflora and Abies holophylla were found in the medium elevation area that has medium level of $Mg^{{+}{+}}$, $Ca^{{+}{+}}$, and C.E.C., while Kalopanax pious, Carpinus cordata and Acer truncatum in the moderately moist and valley area that has high level of $Mg^{{+}{+}}$, $Ca^{{+}{+}}$, and C.E.C. Pinus densiflora and Fraxinus rhynchophylla seemed to prefer the slightly dry, low elevation and ridge area.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.730-740
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• 2012

Korea Expressway Corporation have a plan to make a new highway from East Hongcheon to Yanayang in Kangwon-do(province). This research was conducted to analyze a vegetation structure of japanese red pine forest and to prepare conservation and restoration basic information for minimizing the effects on pine mushroom producing by road construction. Considering the range of effects by road construction, twenty plots were set up near road construction reserved area, and surveyed. The result analyzed by TWINSPAN, one of the classification technique, showed that the communities were divided into four groups which are two Pinus densiflora community, Pinus densiflora-Quercus variabilis community and Pinus densiflora-Deciduous broad leaves forest community(IV). Species diversity index of each community ranged from $1.7353{\pm}0.0341$ to $1.9079{\pm}0.2471$, and the average number of species was $9.2{\pm}2.8$, especially $9.6{\pm}5.0$ at canopy layer in the unit area($100m^2$). The number of individuals ranged from 4 to 29 and average 9.55 in the unit area($100m^2$). The average RSI(relative space index) was below 35%, the average estimated age of the forest was $38{\pm}8.34$ years. The depth of $A_0$ layer of soil was 4~6cm and the range of soil acidity was pH4.70~5.63(average pH 5.29). Pine mushroom and Japanes red pine have a close symbiosis relation. Therefore it is needed that minimizing the read construction which goes through the pine mushroom producing area. If a road goes through a pine mushroom producing area, restoration measurement is prepared to prevent forest from rapid change such as succession or vegetation structure.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.523-530
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• 2020

Based on the results of harmful algal blooms (HABs) monitoring by the National Institute of Fisheries Science and local governments, the effects of changes in the marine environment on HABs are described. Since the beginning of HABs monitoring in 1972, they continued to increase from the 1980s to the 1990s. After the largest number of HAB incidents (109) in 1998; the trend declined until the 2010s. Most HABs in the 1970s were caused by diatoms. In the 1980s, coastal dinoflagellates caused HABs; Cochlodinium polykrikoides blooms have been occurring continuously since 1993. There are three HAB species that cause damage to fisheries in Korea. The high-density bloom of Karenia mikimotoi caused mass mortality in shellfish in Jinhae Bay in 1981. Karenia sp. blooms occurring around Tongyeong in 1992 killed aquaculture fish. Since the occurrence of the largest fisheries damage of KRW 76.6 billion in 1995 caused by C. polykrikoides blooms, they have been occurring continuously. The concentration of nutrients in coastal waters was the highest in the 1980s and has declined since the mid-1990s. This reduction in nutrient concentration is a good explanation for the decreasing number of HABs. Since 2016, a summer high water temperature of 30℃ or more has appeared, and the range and scale of C. polykrikoides blooms have been greatly reduced. In 2016, K. mikimotoi blooms occurred around Wando, Jangheung and Goheung and small scale blooms of C. polykrikoides occurred around Yeosu. There were no C. polykrikoides blooms in 2017; however, Alexandrium affine blooms occurred from Yeosu to Tongyeong. There was a small-scale blooms of C. polykrikoides in 2018 compared to those in the previous years. Our results show that reduction in nutrients and the high water temperature owing to climate change are a good explanation for variation in HABs in Korean coastal waters.