In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation an...In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.展开更多
Tree-ring chronologies from pine,oak and black locust tree species were used to reconstruct annual streamflow and examine hydrological drought years for Palgong Mountain forested watershed in southeastern South Korea ...Tree-ring chronologies from pine,oak and black locust tree species were used to reconstruct annual streamflow and examine hydrological drought years for Palgong Mountain forested watershed in southeastern South Korea for the period from 1954-2015. The backward elimination multiple regression analysis provided the statistically significant predictor chronologies of streamflow. The final calibration and verification test models accounted for 84.8% and 81.6%,respectively,of the variability in streamflow observed in the gage data. Further verification of the validity of the reconstructed model was undertaken with the Pearson Correlation Coefficient,the Reduction of Error Test,and the Durbin-Watson Statistics and indicated fidelity of the model for reconstructing the annual streamflow. Analyses of the reconstructed annual streamflow indicate that the most persistent years of high flows above the median annual discharge occurred from 1986-2008.This period included 7 single or multiple years of highest flow above the 90 th percentile discharge and multiple years of high flows with a time interval of 2-6 years,although with intervening multiple years of low flows below the 10 th and 50 th percentile. In comparison,the most persistent years of low flows below the median annual discharge occurred from 1954-1985 and 2009-2015. This period included 8 single or multiple years of lowest flow below the 10 th percentiledischarge and multiple years of low flows with a time interval of 2-9 years,although also with intervening multiple years of high flows above the 50 th percentile. No single years of extreme hydrological droughts below the 10 th percentile were identified from 1986-2015 whereas a greater proportion of high flows above the 90 th percentile occurred during this period. The persistent single or multiple years of lowest flows between 1954 and 1985 were the recent most critical hydrological drought years identified in the Palgong Mountain forested watershed providing supportive evidence of the severity of past hydrological droughts during that period,applicable to the southeastern South Korea where the study watershed is located. This interpretation agrees with the hydrological drought event years identified from 1951 to the early 1980 s in a related national study that used precipitation proxy data to reconstruct past occurrences of droughts in Korea.展开更多
In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strai...In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strains on the basis of morphological and molecular data. The cellular dimensions of the Chinese Wenling strain (LAMB090508) and Korean strain (PDKS0206) were similar and the cells of both strains were of asymmetric and elongated shape. The posterior end of most cells was rounded. Megacytic zones of aged cells were broader with dense tiny knobs. The roundish nucleus was located in the posterior part of the cell. A few irregular shaped chloroplasts were distributed within the cell. The nucleotide similarity of the two strains, determined from the 5.8S rDNA-ITS sequences, was 99.83%. The comparative results of morphology and molecular analysis suggest that both strains isolated from China and Korea were the identical species, Prorocentrum donghaiense Lu.展开更多
Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research ...Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin bar- ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per- centage and importance value （IV） of erustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae （mean IV=62%） as well as Sargassum sp. （mean IV=28%）, and Gelidium amansii （mean IV= 19%） were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii （mean IV = 32%） underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di- verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.展开更多
Four types of Doenjang were prepared from 100% （w/w） defatted soybean （DFS）, a mixture of 80% （w/w） defatted soybean and 20% （w/w） glasswort （DFS-G）, a mixture of 80% （w/w） defatted soybean and 20% （w/w）...Four types of Doenjang were prepared from 100% （w/w） defatted soybean （DFS）, a mixture of 80% （w/w） defatted soybean and 20% （w/w） glasswort （DFS-G）, a mixture of 80% （w/w） defatted soybean and 20% （w/w） rice （DFS-R）, or a mixture of 60% （w/w） defatted soybean, 20% （w/w） glasswort and 20% （w/w） rice （DFS-GR）. Maturity of the DFS-G doenjang was the highest, which was proportional to total amino acid content. Antioxidative compounds and total amino acids were relatively higher in the doenjang with glasswort （DFS-G, DFS-GR） than those in the other preparations （DFS, DFS-R）. Succinic and pyroglutamic acid were relatively higher but levulinic acid was relatively lower in the doenjang with glasswort compared to those in the others. Mn, Fe, Zn, and Al were relatively higher in the doenjang with glasswort compared to those in the others. Volatile organic compounds were differently produced depending on doenjang type and influenced definitely by addition of glasswort and rice. Some bacterial communities responsible for meju fermentation were changed during ripening for doenjang whereas others were conserved.展开更多
Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of im...Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.展开更多
文摘In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.
基金support of Forest Science and Technology Projects (Project No.S211215L020210) provided by Korea Forest Service
文摘Tree-ring chronologies from pine,oak and black locust tree species were used to reconstruct annual streamflow and examine hydrological drought years for Palgong Mountain forested watershed in southeastern South Korea for the period from 1954-2015. The backward elimination multiple regression analysis provided the statistically significant predictor chronologies of streamflow. The final calibration and verification test models accounted for 84.8% and 81.6%,respectively,of the variability in streamflow observed in the gage data. Further verification of the validity of the reconstructed model was undertaken with the Pearson Correlation Coefficient,the Reduction of Error Test,and the Durbin-Watson Statistics and indicated fidelity of the model for reconstructing the annual streamflow. Analyses of the reconstructed annual streamflow indicate that the most persistent years of high flows above the median annual discharge occurred from 1986-2008.This period included 7 single or multiple years of highest flow above the 90 th percentile discharge and multiple years of high flows with a time interval of 2-6 years,although with intervening multiple years of low flows below the 10 th and 50 th percentile. In comparison,the most persistent years of low flows below the median annual discharge occurred from 1954-1985 and 2009-2015. This period included 8 single or multiple years of lowest flow below the 10 th percentiledischarge and multiple years of low flows with a time interval of 2-9 years,although also with intervening multiple years of high flows above the 50 th percentile. No single years of extreme hydrological droughts below the 10 th percentile were identified from 1986-2015 whereas a greater proportion of high flows above the 90 th percentile occurred during this period. The persistent single or multiple years of lowest flows between 1954 and 1985 were the recent most critical hydrological drought years identified in the Palgong Mountain forested watershed providing supportive evidence of the severity of past hydrological droughts during that period,applicable to the southeastern South Korea where the study watershed is located. This interpretation agrees with the hydrological drought event years identified from 1951 to the early 1980 s in a related national study that used precipitation proxy data to reconstruct past occurrences of droughts in Korea.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2007AA09Z110)the National Basic Research Program of China (973 Program) (No. 2010CB428702)+2 种基金Foundation of SOA (Nos. 201005031, 2009123)the Basic Research Fund of SIO (No. JG200818)Joint Project between Germany and China supported by International Bureau of BMBF at DLR (No. CHN 06/009)
文摘In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strains on the basis of morphological and molecular data. The cellular dimensions of the Chinese Wenling strain (LAMB090508) and Korean strain (PDKS0206) were similar and the cells of both strains were of asymmetric and elongated shape. The posterior end of most cells was rounded. Megacytic zones of aged cells were broader with dense tiny knobs. The roundish nucleus was located in the posterior part of the cell. A few irregular shaped chloroplasts were distributed within the cell. The nucleotide similarity of the two strains, determined from the 5.8S rDNA-ITS sequences, was 99.83%. The comparative results of morphology and molecular analysis suggest that both strains isolated from China and Korea were the identical species, Prorocentrum donghaiense Lu.
基金supported by a grant from the NIFS Fisheries Research Project ‘Development for Coast-Specific IMTA Technology (R2016015)’, Republic of Korea
文摘Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin bar- ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per- centage and importance value （IV） of erustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae （mean IV=62%） as well as Sargassum sp. （mean IV=28%）, and Gelidium amansii （mean IV= 19%） were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii （mean IV = 32%） underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di- verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.
文摘Four types of Doenjang were prepared from 100% （w/w） defatted soybean （DFS）, a mixture of 80% （w/w） defatted soybean and 20% （w/w） glasswort （DFS-G）, a mixture of 80% （w/w） defatted soybean and 20% （w/w） rice （DFS-R）, or a mixture of 60% （w/w） defatted soybean, 20% （w/w） glasswort and 20% （w/w） rice （DFS-GR）. Maturity of the DFS-G doenjang was the highest, which was proportional to total amino acid content. Antioxidative compounds and total amino acids were relatively higher in the doenjang with glasswort （DFS-G, DFS-GR） than those in the other preparations （DFS, DFS-R）. Succinic and pyroglutamic acid were relatively higher but levulinic acid was relatively lower in the doenjang with glasswort compared to those in the others. Mn, Fe, Zn, and Al were relatively higher in the doenjang with glasswort compared to those in the others. Volatile organic compounds were differently produced depending on doenjang type and influenced definitely by addition of glasswort and rice. Some bacterial communities responsible for meju fermentation were changed during ripening for doenjang whereas others were conserved.
基金Supported by the East Asian Seas Time Series-I(No.EAST-I)the Ministry of Oceans and Fisheries,Korea,the"Development of Microbial Metagenomic Techniques for a Fine-Scale Seawater Mass Analysis"through the Ministry of Education of the Republic of Koreathe National Research Foundation of Korea(No.NRF-2013R1A1A2006915)
文摘Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.
