• Journal of Ecology and Environment
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• v.39 no.1
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• pp.17-29
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• 2016

We conducted the study on the relationship between the distribution of coastal sand dune plants and edaphic factors from the shoreline to inland in sand dune ecosystem. The application of TWINSPAN classification based on 10 species, led to the recognition of three vegetative groups (A-C), which associated with their habitats (foredune, hummuck in semistable zone and stable zone). The associations were separated along soil gradient far from the seashore. The relationships between species composition and environmental gradients were explained by canonical correspondence analysis (CCA). Distance from the shoreline was an important indicator to determine soil properties (pH, total ion contents, sand particle sizes, organic matters and nitrogen contents) from the seaward area to inland area and distribution pattern of coastal sand dune plants. Group A is foredune zone, characterized by Calystegia soldanella; group included typical foredune species such as Elymus mollis, Carex kobomugi, Ixeris repens, C. soldanella and Glehnia littoralis. Group B on semi-stabilized zone was characterized by Vitex rotundifolia, a perennial woody shrub. This group was associated the proportion of fine sand size (100 to 250 μm). The results on the proportion of soil particle size showed a transition in sand composition, particularly with respect to the proportion of fine sand size that occurred from the foredune ridge at 32.5 m to the Vitex rotundifolia community at 57.5 m from the shoreline. Group C on stabilized zone was characterized by Zoysia macrostachya, Lathyrus japonicus and Cynodon dactylon and were associated soil organic matter and nitrogen contents. The spatial distribution of plants in the Goraebul coastal sand dune system may result from the interactions between the plant species and environmental heterogeneity.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.320-331
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• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.426-433
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• 1986

This experiment was carried out to investigate the competitive ability and the interaction of each species in ten mono-and binary-associations of four forage species; orchardgrass, tall fescus, ladino clover, and alfalfa. Each species was grown in intra- and interspecific stands in large pots for one year. And samplings of shoot and root were taken in Spring, Summer, and fall clipping stages. Intra- and interspecific competition was compared and evaluated by expected yield, aggressivity, relative yield total(RYT), compensation index(CI), general combining ability(GCA), and specific combining ability (SCA) with shoot and root dry matter production of each species in monoculture and binary mixture. The forage yield was high in two grass species and the mixture of them, but low in two legume species and the mixture of them. The mixture of tall fescue-ladino clover was evaluated as a productive association with a high PYT(1.05) and a high SCA(0.79), and tall fescue was a more aggressive species in it. Each of grass-grass and legume-legume mixture was less aggressive between two species and lower SCAs than grass-legume mixtures. Especially, orchardgrass was the most agressive species and alfalfa was the least, but tall fescue had the highest GCA and ladino clover had the lowest in shoot competition. Also in root, tall fescue- ladino clover mixture was a good match with a high RYT(l.12) and a high SCA (0.60), and orchardgrass was highest in aggressivity. However, orchardgrass had the highest GCA in root while tall fescue had the highest in shoot.

• Mycobiology
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• v.30 no.3
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• pp.146-153
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• 2002

Two types of mycorrhizae, orchid(OM) and arbuscular mycorrhizae(AM), were observed in the cortical cells of Botrychium ternatum roots. The vesicles or arbuscules of AM fungi were examined and the fresh or digestive pelotons by other species of basidiomycetes were also observed in the roots under light microscope. These symbioses were, as the genomic DNAs extracted from roots of B. ternatum reacted with the specific primers, confirmed with PCR technique, being added to more strong evidences. These discoveries were rarely happened in the roots, especially a fern in nature. OM was observed in the roots of B. ternatum collected from the nationwide areas, whereas AM was only in the roots of B. ternatum collected from Chung-Buk areas. It is speculated that OM are associated with the nitrogen cycle in Islands and the growth of B. ternatum in the inland of Central Korea is related to both the phosphate and nitrogen cycle in the nature. The results suggest that B. ternatum is a typical species with two types of mycorrhizae under various growing conditions.

• The Korean Journal of Ecology
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• v.8 no.2
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• pp.89-98
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• 1985

Correlations between horizontal distributions of bamboos (Bambusaceae) in the Korean peninsula and environmental factors were studied using taxanomic and geographical literatures, both old and current. The vertical distributions of bamboos on Mt. Chiri were also studied, and environmental factors limiting horizontal and vertical distributions were compared. There are 18 species of bamboos (belonging to 5 genera) distributed in the Korean peninsula. The distributional range of each genus were distinct, although overlapped. Northern limit of bamboos of any species was marked by the line connecting Paikryung Island (124。40'E, 38。00'N), Mt. Changsoo, Mt. Myungji, Mt. Myohyung and Myungchum (129。40'E, 41。10'N). The optimum range of bamboos was concluded to be restricted to several southern province, with annual precipitation over 1,200 mm. The limiting factors on the distribution were inferred to be low temperature and duration of it. Mean daily minimum temperature of January and the number of days with daily mean temperatures below zero during January showed close associations with the distributional range, and an environmental factors favouring the distributrion of bamboos appeared to be vicinity of warm sea current, deep and extended snow acculation and southern exposure. The vertical distribution of bamboos on Mt. Chiri was limited by low temperature, unfavorable topographic and edaphic conditions caused by steep slope. Difference in the vertical limits between SE and NW slopes are caused by the differences in temperature and precipitation between the slopes. Bamboos were more abundant in valleys than on the ridge, apparently because the deeper snow in the valleys protected the plants from low temperature, heavy winter winds and desiccation.

• Ocean and Polar Research
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• v.23 no.2
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• pp.63-75
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• 2001

Species composition and community structure of the fouling found on the hulls of 28 ships traveling through 6 main shipping routes (SR)in the Far East Sea Basin were analyzed using statistical methods. Samples obtained during 1976-1990 expeditions of the Institute of Marine Biology were used for the analyses. These samples were taken from the ships anchored in the harbor by SCUBA diving and in dry-docks of the Vladivostok ship-repairing yard. Similar composition of the fouling communities occurred on the ships travelling the same SR. In five cases, fouling was dominated by different Cirripedia communities. And, in one case, a community of the mussel Mytilus trossulus was found. In most cases the results of the factor analyses showed extremely low level of the relationships among different animals and algal species in fouling communities. Each ocean-going ship had an original structure of the fouling. Spatially disconnected animal associations of tropical and boreal origin may simultaneously coexist at the same ship. This paper testified to the originality of the zone of anthropogenic substrata as a benthos concentrator in the pelagic regions of the world ocean. The fouling from different zones showed that each zone possesses peculiar features and regularities of the composition and relationships between organisms dwelling here.

• Toxicological Research
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• v.17 no.4
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• pp.255-265
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• 2001

Epidemiologic studies have demonstrated an association between short-term exposure to particulate air pollutants and increased mortality. However the biological mechanism underlying these associations have not been fully established and also the chemical and physical characteristics of the pollutant particles are not well understood. The metal constituents of air pollutant particles and their bioavailability are considered to Play an important role as possible mediators of Particle-induced airway injury and inflammation. Sprague-Dawley rat alveolar macrophage cells (NR8383) were exposed to airborne and acid-leached particulate matter (PM). Titanium oxide and nickel subsulfide were used as negative and positive controls. Particle-induced reactive oxygen species formation in cells was detected using the fluorescent probe 2',7'-dichlorofluorescin diacetate. Expression of TNF-$\alpha$ and IL-6 were measured by enzyme-linked immunosorbent assay, and PM-induced DNA double-strand breaks were determined with $\lambda$DNA/Hind III marker. Metals associated with air pollutant particles mediated intracellular oxidant production in alveolar macrophages, and the cytotoxicity and proinflammatory cytokine production induced by PM were associated with oxidative stress. The oxidants produced by air pollutant particles also are likely to induce DNA double-strand breaks. Our findings in alveolar macrophage cells exposed to PM and acid-leached PM support the hypothesis that metal components in urban air pollutants and their bioavailabilities might play an Important role in the induction of the adverse health effects.

• The Korean Journal of Ecology
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• v.12 no.4
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• pp.257-284
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• 1989

This study was carried out to characterize pinus densiflora forests in middle province (Mt. Seolag, Mt. Taebaik) south province (Mt. Sokli, Mt. Jiri) and south-coast province (Mt. Daedun) of Korea. The appearance species in the P. densiflora alliance included 325 taxa and varied according to the direction of slopes. The steeper the slope was, the fewer number of taxa were observed. The floristic composition of south-coast province was gradually changing to the south hemispheric factors. Dominant species groups of P. densiflora alliance were classified into P. densiflora, Quercus serrata ( layer), Rhus trichocarpa ( layer), Lespedeza maximowiczii var. tomentella (S layer), Artemisia keiskeana, Carex humilis var. nana, Spodiopogon sibiricus (K layer). Quercus variabilis, Fraxinus sieboldiana and Styrax japonica association were formed under the P. densiflora alliance. Quercus, Rhus, Lespedeza and Rhododendron groups maintained high ecological relationships one another. The soil factors (pH, organic matters, and water field capacity)and relative light intensity tended to show negative correlation, which were significantly different among provinces. The P. densiflora forests of Korea were classified into one alliance and four associations, that is, pinion densiflorae Suz.-Tok. 1966, Quercetum variabilae ass. nov., Quercetum mongolicae ass. nov. Fraxinetum sieboldianae ass. nov. and Styraxetum japonicae ass. nov.

• Korean Journal of Environment and Ecology
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• v.16 no.2
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• pp.160-171
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• 2002

In order to clarify the species composition, distribution and habitat of the Korean wild Pyrus ussuriensis and P. pyrifolia communities, that are so expected as a useful resource plant, an investigation was carried out according to phytosociological method on Mts. Hambaek, Ilwol, Sobaek, Juwang and Gaya in Korea. In the present study, we made an attempt to elucidate the autecological characteristics of the wild Pyrus species by synecological approach. As a result, the forests including the Pyrus species were divided into the two associations and two communities, considering the existing vegetation units for the forest; Syneilesio-Quercetum serratae, Corylo-Quercetum mongozicae, Ainsziaea acerifolia- Quercus mongolica community and Fraxinus rhynchophylla-Pyrus ussuriensis community. Among the units, the Syneilesio-Quercetum serratae and the Corylo-Quercetum mongolicae belong to southern type and middile-northern type, respectively, in their distributional type. It is inferred that the wild Pyrus species are distributed preferably in the deciduous forest zone in Korea, compared to the other forest zones. In particular the Pyrus species are present alone or dominantly in only both the tree layer or subtree layer of the forests, reflecting their shade intolerance ecophysiologically. Thus they usually were distributed in SE or SW of slope aspect. Generally the canopy of the forests including the Pyrus species was so open. Species diversity of the vegetation units was highest in the Syneizesio-Quercetum serratae and lowest in the Ainsliaea acerifolia-Quercus mongolica community. The Corylo-Quercetum mongolicae and the Pyrus ussuriensis-Fraxinus rhynchophylla community are medium between the two.

• Animal cells and systems
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• v.3 no.2
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• pp.167-172
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• 1999

We report for the first time the life history of a 'social' spider, Philoponella prominens, living in a temperate region. Philoponella prominens hibernated as immatures or subadults for 7-8 months in 1995 and 1996 from September-October to April-May in central Korea. When they emerged from their winter hibernation, a majority began their lives as commensals in the webs of other species. As the mating season approached, however, commensal spiders switched to become colonial or solitary. The mating season began in early June and lasted until early August. Newly-hatched spiderlings began to appear in the field in late June. They formed a colony by building their webs connected to the mother's by using pan of the mother's web as supporting substrates. As the season progressed, however, some of the colonial spiderlings became commensal or solitary individuals. Our field observations suggest that Philoponella prominens form colonies or commensal associations to reduce the web-building cost.