• Ocean and Polar Research
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• v.35 no.2
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• pp.181-191
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• 2013

To investigate the occurrence of modern living planktonic foraminiferal species and their seasonal variations around Jeju Island, we conducted planktonic foraminiferal sampling at KIOST's regular sampling sites during 16 months. In total seven genus and 16 modern planktonic foraminiferal species were identified with six dominant species. Dominant species were Gloigerinoides sacculifer, Globigerinoides ruber, Globigerina bulloides, Noegloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia inflata. Most of the species were characterized as being typical subtropical species and showed seasonal variations and/or intermittent occurrence from season to season. The occurrence of living foraminifera revealed a strong relationship with water temperature, but not with salinity. Species succession seems to occur along with water temperature changes. Some patch distribution and water temperature dependences appear to be significant since there is a high degree of variation in the occurrence patterns of species and standing stock. More detailed quantitative study is necessary to confirm the species diversity and seasonal variations of planktonic foraminifera and related ocean environmental changes.

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.1-9
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• 2002

In order to understand the relationship between succession of phytoplankton community structure and inorganic nutrients and particulate organic matters, a one station in Kyungan stream in Korea during the dry season was chosen. Water samplings were carried out once a week from 18 August to 13 November 1993. The DIN concentration distributed always abundantly, however, phosphate and silicate gradually reduced during the period. Phytoplankton community had a peak chlorophyll a concentration of $90.6\;{\mu}g/l$ in late summer (21 August 1993) and a second peak of $29.7\;{\mu}g/l$ in autumn (2 October 1993). After then late autumn was characterined by relatively low chlorophyll a concentration of $15{\sim}16\;{\mu}g/l$. Seasonal fluctuation of chlorophyll a concentrations were correlated with measured POC and PON concentrations: phytoplankton blooming may be a major factor controlling POC and PON concentrations in this ecosystem. Phosphate plays an most important role as a limiting factor of phytoplankton growth. However, when Si/P ratio low, silicate may be a more critical limiting factor than phosphate. Shifts of P-limitation to Si- limitation the succession of dominant phytoplankton can in duce: diatom to cyanobacteria such as Anabaena, Microcystis and Oscillatoria.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.1
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• pp.25-35
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• 2015

Pennisetum aloperculoides is a key revegetation species mixed with other plants species and used for revegetating cut-slopes. The purpose of this research is to identify the effects of mixed seeding of revegetation plants on cut-slope revegetation with respect to the quantity of Pennisetum aloperculoides seeds. The coverage ratio and appearance frequency of Pennisetum aloperculoides, and other revegetation species were measured to assess the cut-slope revegetation. We divided Pennisetum treatments into four groups with different Pennisetum seed quantities of $0g/m^2$, $5g/m^2$, $10g/m^2$, and $15g/m^2$. For each treatment group, we mixed identical quantities of seeds from herbaceous flowers (bird's-boot trefoil, aster, chrysanthemums, golden coreopsis and china pink), cool-season turfgrasses, and woody plants (korean lespedeza, indigo and silk tree). The increase in the quantity of the Pennisetum seeds resulted in the higher coverage ratio for Pennisetum, but in the lower coverage ratio for herbaceous flowers, cool-season turfgrasses, and woody plants. We observed a short-term succession process in which the dominant species shifted in the following order: the initial species Pennisetum, herbaceous flowers, and then lastly woody plants. In case of the appearance frequency, we also observed the higher appearance frequency for Pennisetum and the lower appearance frequency for the other plants due to the increase in the quantity of Pennisetum seeds. Pennisetum, bird's-foot trefoil and china pink showed the tendency to decrease the appearance frequency from one month after seeding while cool-season turfgrasses became extinct due to summer drought. In the woody plants, the appearance frequencies of korean lespedeza and indigo were high due to the decrease in quantity of Pennisetum seeds. The silk trees were damaged from winter frost and none emerged at all in 2013 (the following year after the seeding). Korean lespedeza and indigo appeared to have the short-term rapid dominance over other treated revegetation plants.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1445-1456
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• 2010

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 mm, increasing by 20% from the average annual level of 1,506.7 mm in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were $3,799kgday^{-1}$, and 81% of them came from livestock and household. The TN and TP loads were $1,164kgday^{-1}$ and $170kgday^{-1}$, respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells $mL^{-1}$) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.278-288
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• 2012

The zooplankton community of Lake Paldang, Korea, was investigated on a weekly basis from 2004 to 2006. The seasonal succession of zooplankton community structure was influenced by hydrological factors such as rainfall pattern and efflux in Lake Paldang. According to the monsoon climate, spring, fall and winter had reduced precipitation, so that zooplankton dynamics of the lake showed a typical succession pattern. In spring, small sized and faster growing rotifera rapidly increased, and copepods and cladocera noticeably increased thereafter. Rotifera dominated the zooplankton community, occupying more than 90% of total zooplankton abundance. Among rotifera, Keratella cochlearis was extremely dominant in spring. Copepoda were mainly present as Copepodid and Nauplius. Among cladoceran species, Bosmina longirostris was dominant. In summer, during the rainy season, zooplankton were flushed out by an associated dam. After the rainy season, rotifera increased rapidly when the water column of the lake was stable. During the fall, zooplankton abundance gradually reduced in accordance with decreasing water temperature. However, the occupation rate of copepod (Copepodid, Nauplius) increased relatively. Zooplankton dynamics were influenced by meteorological changes and hydraulic-hydrological factors, because Lake Paldang is a completely closed ecosystem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.69-79
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• 2005

This study was carried out to select proper species for early stage replantation in highway cut-slope area. In highway cut-slope area, sample plots of 106 were selected, and their vegetations and environmental factors were investigated. 1. We found total 172 species in the 106 cutting area of highway. The species of high frequency of highway cut-slope were found in the order of Lespedeza bicolor, Artemisia princeps var. orientalis, Festuca arundinacea, Erigeron annuus, Lespedeza cuneata, Lactuca indica var. laciniata, Eragrostis curvula, Dactylis glomerata, Oenothera lamarckiana, Wistaria floribunda, Humulus japonica, Commelina communis, Miscanthus sinensis, Pueraria thunbergiana, Pinus densiflora, etc. 2. The average vegetation coverage was over 90% in the study sites and the average coverage was 91.4% in the total cut-slope area. The species of high coverage of highway cut-slope area were found in the order of Festuca arundinacea, Eragrostis curvula, Lespedeza bicolor, Wistaria floribunda, Lespedeza cuneata, Dactylis glomerata, Artemisia princeps var. orientalis, Humulus japonica, Pueraria thunbergiana, Robinia pseudoacacia, Poa pratensis, Medicago sativa, Festuca ovina, Pinus densiflora, Parthenocissua tricuspidata, etc. 3. The total coverage in the foreign plants of Festuca arundinacea, Eragrostis curvula, Dactylis glomerata, Poa pratensis, Medicago sativa, Coreopsis drummondii and native plants of Lespedeza bicolor, Wistaria floribunda, Lespedeza cuneata, Amorpha fruticosa, Indigofera pseudotinctoria, Lespedeza cyrtobotrya were 57.52%. That is, the ecological succession of native herbs and parachute shrubs have delayed because the afforested plants occupy 57.52%. In future, the coverage of foreign herbs have to reduce, and the coverage of the native herbs and parachute shrubs must be increased. 4. The native seed of Artemisia sp., Miscanthus sinensis, Smilax china, Pueraria thunbergiana, Rubus crataegifolius, Rubus parvifolius, Pinus densiflora, Rhus chinensis, Albizzia julibrissin, Rhododendron mucronulatum, Clematis apiifolia, Zanthoxylum schinifolium, Prunus sargentii could be added in the seedling of the temperate south zone highway with the used seeds. The native seed of Artemisia sp., Miscanthus sinensis, Rubus crataegifolius, Rhododendron mucronulatum, Weigela subsessilis, Stephanandra incisa, Rhus chinensis, Pinus densiflora, Salix koreensis, Cocculus trilobus, Populus alba, Spiraea prunifolia for. simpliciflora, Clematis apiifolia, Lindera obtusiloba, Quercus serrata, etc., could be added in the seedling of the temperate middle zone highway with the used seeds. 5. We have some recommendation. The native plants have to growth in the highway cut-slope area instead of foreign plants to have good environmental ecology. The role of the foreign plants should be the plant for the initial several years in the highway cut-slope area. And, the native plants should growth in the next season. 6. We should protect shrubs and trees in the highway slope area because shrubs and trees can be more helpful in stabilizing of the slope area than herbs.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.242-247
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• 1999

This sludy was conducted to investigate the change of bacterial co~munities with season and depth in Lake Soyang. Korea, using fluorescence in situ hybridization (FISH). The oligonucleotide probes used in this study were EUB338, ALF I b. GAM42a, and CF, The percentage of h e Proleobacteria a $\alpha$-group ranged from 0.70 to 33% the $\beta$-group from 1.0 to 26% they -group from 2.4 Lo 37% and Cytophagn and Flavobactefin groups from 4.7 to 24% duing the study period (April Lo November, 1998). They $\gamma$-group was dominant in spring when Asterionella was dominant. and a $\alpha$-group was dominant in summer when the organic content was low and Dinobryon was dominant. However, a specific group was not dominant in ？dl when cyanobacteria group was dominant and the ratio of eubacleria to total bacteria was very low. Therefore, the bacterial communities in Lake Soyang changed with season and depth, which seems to be associated with the telnporal succession of phytoplanlaons.

• Journal of Ecology and Environment
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• v.37 no.1
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• pp.1-11
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• 2014

To understand the effects of fluctuations in dam discharge due to river environments and phytoplankton communities, we monitored such environments and phytoplankton communities biweekly, from February 2001 to February 2002 and from February 2004 to February 2005, in the lower Han River (LHR), South Korea. The phytoplankton abundance during the dry season was approximately two times higher than that during the rainy season. In particular, fluctuations in diatom assemblages, which constituted over 70% of the total phytoplankton abundance, were affected severely by the changes in the discharge. When a large quantity of water in a dam was discharged into the LHR, the conductivity and the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved inorganic phosphorus (DIP) decreased rapidly, whereas the concentrations of suspended solids (SS), dissolved inorganic nitrogen (DIN), and dissolved silica (DSi) increased immediately. Time-delayed relationship also revealed that the dam discharge had an immediately significant negative relationship with phytoplankton abundance. On the whole, fluctuations in phytoplankton communities in the LHR were influenced much more by hydrodynamics such as dam discharge than by the availability of nutrients. Thus, the variability in these concentrations usually parallels the strength of river flow that is associated with summer rainfall, with higher values during periods of high river discharge.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.99-106
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• 2009

Water spider(Argyroneta aquatica Clerck) is only spider that live under aquatic water. In korea, water spider distributed only in Undari Wetland, Yeochon County, Kyongii Proviance, where it is designated as Natural Monument. I counted the population density, analysed the ecological traits such as actual vegetation map, and suggested conservation strategy and eco-tourism planning for water spider. The population mean density of water spider was one individual/$m^2$ and 8,000 individuals/ha. The wetland inhabited by water spider was characterized by high water level fluctuation between rainy season and dry ones. Wetland plant community was dominated by Phragmites australis and Leersia oryzoides var. japonica with submersed plant, Utricularia japonica. It is need to supply water for inhibiting terrestial succession trend during the dry season and to connect three fragmented wetlands through ecological corridor. Also, It was suggested that ecotourism planning is important for conserving this wetland.