• Asian Journal of Turfgrass Science
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• v.9 no.1
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• pp.53-74
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• 1995

This study was made on the relationships among production structures, biomass and Soil proper-ties of grassland types in Chejudo. The results of this investigation were obtained as foolows. The annual productions of the grasslands of Zoysio, Imperata, Themede, Miscanthus and Pteridium types were 40.36~144.00, 168.28~272.44, 58.24~138.44, 156.12 ~714. 12 and 157. 18~398.40g /m$^2$, respectively. The production structures of those grassland types were different from one another. The water contents, organic matter, total nitrogen and available phosphorus were different levels between grasslands had a simple correlation at 5% level and the organic matter contents were a higher significant at the partial correlation. Key words: Production Structure, Biomass, Soil properity, Chejudo.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.768-775
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• 2015

Seasonal variability in the marine seaweed community structure was examined in the intertidal zones at nine study sites in Hallyeohaesang National Park, on the southern coast of Korea from March to October 2014. A total of 145 seaweeds were indentified, comprising 15 green, 41 brown and 89 red algae. Coarsely branched seaweeds were the dominant functional group, comprising 58.95% in species number, whereas filamentous, sheet, thick leathery, crustose and jointed calcareous forms comprised 2.63-17.72% each. The seaweed biomass averaged 358.00 g dry wt/m² and it was maximal at Somaemuldo (847.64 g dry wt/m²) and minimal at Gamam (56.51 g dry wt/m²). Based on biomass, the dominant and subdominant seaweeds were Ulva australis at Gamam, Sargassum thunbergii at Sangju, Ulva australis and S.fulvellum at Neukdo, S.horneri at Dala-Bijindo-Somaemuldo, S. thunbergii at Dapo, and Corallina pilulifera at Songdo. Community indices were as follows: dominance index (DI), 0.43-0.71; richness index (R), 8.26-16.50; evenness index (J'), 0.36-0.54; and diversity index (H'), 1.57-2.19. In conclusion, we found that both biomass and the community structure of seaweeds in Hallyeohaesang National Park were similar to those in other studies of the Southern Sea along the Korean peninsula, and that Hallyeohaesang National Park is a relatively favorable habitat for seaweeds. Future studies should examine the changes in seaweed composition and biomass as they relate to climate change and environmental pollution.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.54-59
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• 1984

Research was conducted in a minirotation plantation with four different planting densities at Tatae-ri, Chongwoon-myon, Yangpyong-gun, Kyonggi-do, to investigate the relation between volume and biomass production. Nine-year-old Alnus hirsuta var. sibirica analyzed to determine volume yield and weight equations for aboveground parts. The results suggest that the most suitable harvesting or thinning period at highly dense plots, more than 6,000 trees per hectare, is five years after planting, and the most fitted regression equation model for estimating aboveground biomass or total tree biomass is $logY=b_0+b_1logd^2h$.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1551-1558
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• 2014

The esterase gene Est8 from the thermophilic bacterium Bacillus sp. K91 was cloned and expressed in Escherichia coli. The monomeric enzyme exhibited a theoretical molecular mass of 24.5 kDa and an optimal activity around $50^{\circ}C$ at pH 9.0. A model of Est8 was constructed using a hypothetical YxiM precursor structure (2O14_A) from Bacillus subtilis as template. The structure showed an ${\alpha}/{\beta}$-hydrolase fold and indicated the presence of a typical catalytic triad consisting of Ser-11, Asp-182, and His-185, which were investigated by site-directed replacements coupled with kinetic characterization. Asp-182 and His-185 residues were more critical than the Ser-11 residue in the catalytic activity of Est8. A comparison of the amino acid sequence showed that Est8 could be grouped into the GDSL family and further classified as an SGNH hydrolase. Est8 is a new member of the SGNH hydrolase subfamily and may employ a different catalytic mechanism.

• Ocean and Polar Research
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• v.33 no.2
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• pp.135-147
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• 2011

Zooplankton is an important constituent in assessing ecosystem responses to global warming. The northern East China Sea is an important ecosystem for carbon cycling with a net sink of carbon dioxide. Despite their importance as a major component in carbon cycling, relatively little is known about zooplankton biomass structure and its regulating factors in the northern East China Sea. This study examined zooplankton biomass distribution pattern in the region from multiple cruises encompassing various seasons between 2004 and 2009. Results showed that zooplankton biomass exhibits less cross-shelf gradient in general with declining biomass to the eastern shelf towards the Tsushima Current Water. Size-fractionated biomass showed that the 1.0~2.0 mm size group, mostly copepods, dominated zooplankton biomass, comprising 38 to 48% of total biomass. Smaller zooplankton (0.2~1.0 mm) biomass, consisting mainly of Paracalanus spp, a particle eating herbivorous copepod, was positively related to chlorophyll-a concentration, but no relationship was established for larger zooplankton (1.0~5.0 mm). Spatially-averaged mean total zooplankton biomass was also highly related to chlorophyll-a concentration. These result suggest that the long-term trend of zooplankton biomass increase in this region is partly accounted for by the increases of phytoplankton biomass and productivity underway in the region. However, the underlying mechanisms of how sea surface warming in the study area leads to increased phytoplankton biomass and productivity remains unclear.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.401-410
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• 2011

We assayed the effects of simulated acid rain on the mass loss, $CO_2$ evolution, dehydrogenase activity, and microbial biomass-C of decomposing Sorbus alnifolia leaf litter at the microcosm. The dilute sulfuric acid solution composed the simulated acid rain, and the microcosm decomposition experiment was performed at 23$^{\circ}C$ and 40% humidity. During the early decomposition stage, decomposition rate of S. alnifolia leaf litter, and microbial biomass, $CO_2$ evolution and dehydrogenase activity were inhibited at a lower pH; however, during the late decomposition stage, these characteristics were not affected by pH level. The fungal component of the microbial community was conspicuous at lower pH levels and at the late decomposition stage. Conversely, the bacterial community was most evident during the initial decomposition phase and was especially dominant at higher pH levels. These changes in microbial community structure resulting from changes in microcosm acidity suggest that pH is an important aspect in the maintenance of the decomposition process. Litter decomposition exhibited a positive, linear relationship with both microbial respiration and microbial biomass. Fungal biomass exhibited a significant, positive relationship with $CO_2$ evolution from the decaying litter. Acid rain had a significant effect on microbial biomass and microbial community structure according to acid tolerance of each microbial species. Fungal biomass and decomposition activities were not only more important at a low pH than at a high pH but also fungal activity, such as $CO_2$ evolution, was closely related with litter decomposition rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.732-739
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• 2011

Marine algal flora and community structure were examined at four sites at Tongyeong, Korea, from February to December 2009. Eighty-two algal species were identified, including 10 green, 25 brown, and 47 red algae. During the study period, the number of species was highest at the Dukpo (61 species) site followed by the Gajodo (60 species), Yepo (58 species), and Chilchundo (53 species) sites. Seaweed biomass ranged from 578.11 to 678.26 g, with the maximum and minimum at Chilchundo and Yepo, respectively. Dominant species in term of biomass were Sargassum thunbergii at Yepo, Dukpo, and Gajodo and Gelidium amansii at Chilchundo. The vertical distribution from the high to low intertidal zone was Sargassum thunbergii and Chondria crassicaulis; Sargassum thunbergii and Ulva linza; Ulva pertusa, Sargassum fulvellum, and Gelidium amansii. Two groups clearly segregated in a cluster analysis, a Yepo/Dukpo group (group A) and a Gajodo/Chilchundo (B), indicating relatively strong differences in similarity. The seaweed community structure of group A was characterized by higher biomass and higher species richness of brown algae than were observed in group B. Additionally, the biomass ratio and the species richness of green algae was lower in group A. These differences in seaweed community structure may have been resulted from the effects of cold effluents.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.289-295
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• 2016

Study on characteristics of the molluscan community structure and relationship between the structure and environmental variables in the abyssal plain of the East Sea was carried out for 5 years, starting from 2009 until the end of 2015 except 2010 and 2011. The water depth at the study site is approximately 1,600 m at minimum, and maximum depth of 2,000 m and a total of 16 molluscan species including Aplacophora, Gastropoda and Bivalvia were observed. Species with the highest biomass was Thyasira tokunagai, followed by Yoldiella philippiana which were observed at 9 sampling stations every year. Among 4 sampling stations having various depths (1,600/ 1,700/ 1,800/ 2,000 m), the highest diversity for species was observed at water depths of 1,600 m and 1,700 m, but found the lowest at 1,800 m. Both abundance and biomass were found to be negative correlations with water depth (p < 0.05), however, showed a positive correlation with the concentrations of organic matters (p < 0.01, p < 0.05). However, it is interesting to note that both Thyasira tokunagai (biomass, 82.6%; abundance, 44.1%) and Yoldiella philippiana (biomass, 15.9%; abundance, 4.7%) did not show distinctive correlations with water depth as well as concentrations of organic matters (p > 0.05). Therefore, it could be concluded that community structure of both Thyasira tokunagai and Yoldiella philippiana did not appear to be affected by water depth and concentrations of organic matters but geographical characteristics.

• Journal of Microbiology and Biotechnology
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• v.21 no.3
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• pp.293-298
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• 2011

Nitrifying bacterial community structures of suspended and attached biomasses in a full-scale integrated fixed-film activated sludge process were investigated by analyzing 16S rRNA gene sequences obtained from pyrosequencing. The suspended biomass had a higher number of ammonia-oxidizing bacterial sequences (0.8% of total sequences) than the attached biomass (0.07%), although most of the sequences were within the Nitrosomonas oligotropha lineage in both biomasses. Nitrospira-like nitrite-oxidizing bacterial sequences were retrieved in the suspended biomass (0.06%), not in the attached biomass, whereas the existence of Nitrobacter-like sequences was not evident. The suspended biomass had higher nitrification activity (1.13 mg N/TSS/h) than the attached biomass (0.07 mg N/TSS/h). Overall, the results made it possible to conclude the importance of the suspended biomass, rather than the attached biomass, in nitrification in the wastewater treatment process studied.

• Journal of Wetlands Research
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• v.8 no.2
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• pp.65-74
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• 2006

A study of the vascular hydrophyte communities and biomass was undertaken in the Bigumdo wetlands, Shinangun, from March to November, 2005. As a result, the vegetation was divided into 14 communities. Among them, emergent hydrophytes consisted of 6 communities, including Miscanthus sacchariflorus community, Phragmites communis community, Typha angustata community, Leersia japonica community, Paspalum disticum var. indutum community, and Persicaria thunbergii community, floating hydrophytes 5 communities including Hydrocharis dubia community, Nelumbo nucifera community, Euryale ferox community, Trapa japonica community and Nymphaea tetragona var. angusta community, free-floating hydrophytes 2 commuinties including Lemna paucicostata community and Spirodela polyrhiza community, and submergent hydrophyte 1 community, including Myriophyllum verticillatum community. Biomass was the highest at emergent hydrophytes and decreased along the life form, in the order like floating hydrophytes, submergent hydrophyte and free-floating hydrophytes. In addition, hydrophytes in the Bigumdo wetland showed the typical vertical zonation pattern like a natural swamp. These results were considered that the wetland of Bigumdo was characterized by the typical structure of aquatic plant ecosystem.