• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.14-35
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• 2023

Freshwater and brackish blue-green algae were collected at 43 freshwater and brackish sites (including lakes, ponds, swamps, streams, and rivers and estuaries) throughout South Korea from March 2017 to October 2018, and were identified using light microscopy. A total 223 taxa in freshwater and 230 taxa in brackish waters in 2017 and 274 taxa in fresh and brackish waters in 2018 were identified and among them, 20 taxa were unreported taxa of blue-green algae in Korea; The new recorded taxa were Aphanocapsa marina, Calothrix fusca f. durabilis, Calothrix littoralis, Calothrix parva, Chamaesiphon minimus, Chroococcidiopsis cubana, Chroococcidiopsis fissurarum, Coelosphaerium aerugineum, Dolichospermum mendotae, Eucapsis alpine, Gomphosphaeria cordiformis, Gomphosphaeria natans, Merismopedia danubiana, Lynbya aestuarii var. gaditana, Tolypothrix tenuis, Pseudocapsa maritima, Pseudocapsa sphaerica, Pseudophormidium tenue, Trichodesmus sp. and Woronichinia elorantae.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.31-47
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• 1998

This paper deals with the historical geography of land-use and agriculture along the Lower Nam-River floodplains. The reclamation process of the river floodplains, the cultivation methods on the reclaimed lands, and the land-use patterns and processes are investigated. The Nam River, one of the major tributaries of the Nakdong River, flows through the boundary between Ham-An and Eu-Ryong Guns. Larger floodplains are located in Ham-An Gun. The floodplains of Ham-An Gun have been surveyed intensively in this study. In South Korea, the alluvial plains, mostly located along the river valleys, have been reclaimed to provide fertile agricultural lands. Those along the upper river valleys were reclaimed before those along the lower river valleys. The flood-plains of Han-An Gun were reclaimed to be the largest agricultural lands of the Gun. The natural levees along the Lower Nam-River Valley were identified before the reclamation processes but now hardly identified. Relatively larger floodplains are located along the tributary streams of the Nam River. Often there are low-lying back swamps between the natural levees and the hills/mountains that rise above the floodplains. The back swamps, called 'natural bog lands' in this region, have been reduced in size and in number through reclamation for the purpose of agricultural and industrial land-uses. Now about ten 'natural bog lands' are found in the Ham-An floodplains, and some of them are being reclaimed for the industrial land-use. This study suggests the emergent need of conservation for the remaining 'natural bog lands' in terms of ecology. Seven agricultural fields of large size, originated from the Nam-River floodplains, are identified in this study: Kun(큰들), Chung-Am(정암들), Chang-chi(장지들), Baek-San(백산들), Ha-Ki(하기들), Gu-Hae(구혜들), and Chang-Po(장포들) fields. The Kun field was reclaimed during the Japanese control and the Gu-Hae, in the 1950s. All of those except the above two fields were reclaimed after the mid-1960s. The Nam-River Dam in Chinju, completed in 1969, contributed the reclamation processes along the Lower Nam-River floodplains. The rice acreage of the region has been reduced slowly since 1970 but the rice production of the region has been relatively stable (Table 4). Rice culture had been the most important agriculture on the reclaimed lands for decades before the greenhouse vegetable cultivation became more important in the 1980s. Among the vegetables cultivated in the greenhouse, the watermelon is the dominantly leading one. Watermelons are usually harvested two or three times in a year though it is possible to harvest four times in one year. The rotation of watermelons and rice is common in the region. It is known the physical conditions of the Nam-River floodplains in Ham-An Gun is the most suitable for watermelon cultivation in South Korea.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.23-36
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• 2010

The Cat Ba Islands in Hai Phong City, northern Vietnam, consist of a large limestone island with a maximum height of 322 m above sea level and 366 small limestone islets with a total area of about $180\;km^2$. The islands are relicts of karst limestone mountains that became submerged during the Holocene transgression 7000 - 8000 year ago. The combination of the longtime karst process and recent marine processes in the monsoonal tropical zone has created a very diversity landscape on the Cat Ba Islands that can be divided into 3 habitat types with 16 forms. The first habitat type is the karst mountains and hills, including karst mountains and hills, karst valleys and dolines, karst lakes, karst caves, and old marine terraces. The second habitat type is the limestone island coast, including beaches, mangrove marshes, tidal flats, rocky coasts, marine notch caves, marine karst lakes, and bights. The third habitat type is karst plains submerged by the sea, including karst cones (fengcong) and towers (fengling), bedrock exposed on the seabed, sandy mud seabed, and submerged channels. Like the landscape, the biodiversity is also high in ecosystems composed of scrub cover - bare hills, rainy tropical forests, paddy fields and gardens, swamps, caves, beaches, mangrove forests, tidal flats, rocky coasts, marine krast lakes, coral reefs, hard bottoms, seagrass beds and soft bottoms. The ecosystems on the Cat Ba Islands that support very high species biodiversity include tropical evergreen rainforests, soft bottoms; coral reefs, mangrove forests, and marine karst lakes. A total of 2,380 species have been recorded in the Cat Ba Islands, included 741 species of terrestrial plants; 282 species of terrestrial animals; 30 species of mangrove plants; 287 species of phytoplankton; 79 species of seaweed; 79 species of zooplankton; 196 species of marine fishes; 154 species of corals; and 538 species of zoobenthos. Many of these species are listed in the Red Book of Vietnam as endangered species, included the white-headed or Cat Ba langur (Trachypithecus poliocephalus), a famous endemic species. Human activities have resulted in significantly changes to the landscape end ecosytems of the Cat Ba islands; however, many natural aspects of the islandsd have been preserved. For this reason, the Cat Ba Islands were recognized as a Biological Reserved Area by UNESCO in 2004.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.73-87
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• 2004

This study was carried out on Sihwa reclaimed area from January to December in 2003. We observed total 169,351 individuals of 70 species(22 species of waders, 9 species of egrets and 5 species of gulls). Waterbird population was the largest in March(95,465 individuals) and was the smallest from April to June(less than 7,000 individuals). The most dominant species was Pintail(Anas acuta: 58,627 individuals, 34.6%) and other species were Mallards(Anas platyrhynchos: 24.5%), Common Pochards(Aythya ferina: 13.8%), Black-tailed Gulls(Larus crassirostris: 6.1%), Spotbill Ducks(Anas poecilorhyncha: 5.0%) and Greater Scaups(Aythya marila: 2.69%). Sihwa reclaimed area supported many kinds of protected species such as Chinese egrets(Egretta eulophotes), Black-faced Spoonbills(Platalea minor), Eurasian Spoonbills(Platalea leucorodia), Mute Swans(Cygnus olor), Whooper Swans(Cygnus cygnus), and Eurasian Oystercatchers(Haematopus ostralegus). They foraged at waterside of Sihwa lake and rested at reclaimed area. Particularly, Eurasian Oystercatchers bred in habitats with Salicornia herbacea and Suaeda japonica. Reclamation of mud flats and construction of roads, transmission towers and tide embankments disturbed waterbirds in breeding and foraging. We suggest that waterbirds are protected in different action plans according to their status such as breeding, passaging and wintering birds. Maintaining of waterside and swamps in Sihwa reclaimed area will be useful for breeding waterbirds. It is needed to make a protect zone for ecological connecting belt from Oeji isarea, Hyeong isarea, Eum isarea to upper channel on Sihwa lake.

• Korean Journal of Environmental Biology
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• v.18 no.4
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• pp.367-376
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• 2000

Euglenoids occurring in freshwaters are indicator organisms to be used for assessing water quality and applying to environmental education. One hundred sixty eight taxa of euglenoids belonging to three orders, four families and nine genera occur in various waters, especially in eutrophicated and polluted places in Korea. Members of Euglena and Strombomonas are abundant in urban drainages and old ponds, and those of Trachelomonas, Phacus, and Lepocinclis often occur in stagnant waters such as natural wetlands and old swamps. Population size of some euglenoids is significantly correlated to nitrogenous nutrients. Euglena caudata, E. doses, E. ehrenbergii, E. haemichromata, E. geniculata, E. viridis, Lepocinclis ovum, Strombomonas urceolata, Phacus trypanon, Trachelomonas hispida, and T volvocina cells in Korea bloomed in winter and spring, when other phytoplanktonic algae greatly decrease. Blooming of euglenoids indicates tolerance to pollutants and positive selection as a result of competition with other phytoplankton species. We developed a web site on green euglenoids (Yahoo. com: Science/ Biology/ Botany/ Phycology/ Biology of Green Euglenoids), which may be use d for cyber education of water environment. We also presented a method for assessing water quality using diversity and population size of euglenoids, which is considered to be suitable for environmental education of polluted waters.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.251-260
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• 2016

Groundwater flow due to hydraulic gradients across a geologic barrier surrounding a dam reservoir can cause swamps or wetlands to form on the downstream side of the dam, thereby restricting land use. The difference in head between the reservoir level and the downstream groundwater level creates a hydraulic gradient, allowing water to flow through the geologic barrier. We constructed a drainage system at the Daecheong dam to study the effects on groundwater levels and soil moisture contents. The drainage system consisted of a buried screened pipe spanning a depth of 1-1.5 m below a land surface. Groundwater levels were monitored at several monitoring wells before and after the drainage system was installed. Most well sites recorded a decline in groundwater level on the order of 1 m. The high-elevated site (monitoring well W1) close to the reservoir showed a significant decline in groundwater level of more than 2 m, likely due to rapid discharge by the drainage system. Soil moisture contents were also analyzed and found to have decreased after the installation of the drainage system, even considering standard deviations in the soil moisture contents. We conclude that the drainage system effectively lowered groundwater levels on the downstream side of the dam. Furthermore, we emphasize that water seepage analyses are critical to embankment dam design and construction, especially in areas where downstream land use is of interest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.71-76
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• 1970

The freshwater shrimp, Macrobrachium nipponensis is one of the largest species as well as one of the Important types of food. It can be found widely in rivers and swamps from Che-ju island in the south to Chung-ju in the north. The larval development of these shrimps was studied by Yu (1966) and CHUN and YU (1967), but they didn't provide any other features. Shrimps for the present study were collected from the Ntk-Dong River, near Pusan, once each month from March to December 1963. The following is a summary of the results. 1. The relationship between the carapace length (X) and the body length (Y) is: Y=2.68996X+1.14784 in female. Y=2.73121X+1.10827 in male. 2. The relationship between the carapace length(X)_ and tile basipodite length of the 2nd pereiopode (Y) is: Y=0.16910X-0.06422 in female Y=0.19410X-0.06075 in male. 3. The relationship between the carapace length (X) and the ischiorodite length of the 2nd pereiopode (Y) is: Y= 0.48524X-0.10812 in female. Y= 0.69052X-0.28616 in male. 4. The relationship between the carapace length(X) and the meropodite length of the End pereiopode (Y) is: Y=0.51217X-0.04088 in female. Y= 1.9792X-0.98258 in male. 5. The relationship between the carapace length (X) and the carpopodite length of the 2nd pereiopode (Y) is: Y=0.87701X-0.33919 in female. Y=2.00091X-1.64116 in male. 6. The relationship between the carapace length (X) and the propodite length of the 2nd pereiopode (Y) is: Y= 1.04672 X-0.50727 in female. Y=2.67663X-2.40488 in male. 7. The relationship between the carapace length (X) and the dactylopodite length of the 2nd pereiopode (Y) is: Y=0.26366 X+0.15743 in female. Y=1.04866 X-0.67781 in male.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.159-172
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• 2008

This study was carried out to obtain ecological information necessary for a conservation plan based on the distributional patterns, wetland types, and hydrophytic characteristics of urban wetlands in Seongnam City, Kyunggi Province where representing the various patterns of land use made by rapid urbanization since 1970s. Total 162 sites of four wetland types were identified as urban wetlands during the first survey. The sites were classified into 55 forested swamps, 4 riverine wetlands, 62 abandoned paddy fields, 37 small ponds, and 4 reservoirs, etc. The second survey targeted 107 sites which were identified as good wetlands. It showed that 42 sites(about 39%) were already degraded due to drainage, landfill, and crop cultivation at 6 months intervals. Both hydrologic conditions and hydrophytic characteristics of 27 good wetlands help maintain current ecological status, but most wetlands have been degraded by artificial impacts. Among 184 species identified, only 75 species(about 40.7%) were hydrophytes. Prevalence Index of hydrophyte based on three categories of OBL(obligatory wetland plant), FAC(facultitative plant), UPL(obligatory upland plant) was 3.7, indicating that vegetation data alone is inadequate to designate as wetlands. This study revealed that as critical habitats for wildlife they playa vital role in ecotone between both terrestrial and aquatic ecosystem with its proper distributional pattern in spite of their small areas compared to the entire geographic region of the City.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.583-599
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• 2008

Dokdo, small island located in the eastern end of the Korean Peninsula, has been an uninhabited island for long time due to long distance from the land. Moreover, the steep slope of volcanic tuff at Dokdo is well drained for high permeability and Dokdo has few plain areas, swamps and very thin soil layers. In this study, pollen analysis at Dokdo was attempted on the profile of organic sandy soil for the first time in Korea owing to the marine climate environment with high humidity and precipitation including snowfalls in spite of unprofitable condition geologically or geomorphologically. While many historical, political researches have been accumulated for territorial problem of Dokdo with Japan, natural scientific researches with field work are not sufficient, and few paleoecological researches have been done. As a result of pollen analysis, the ratio of the NAP(Non-Arboreal Pollen) and spore was higher than AP(Arboreal Pollen), and the vegetation change existed by showing dramatic decrease of AP at the upper layer. AP was composed of almost Pinus, and a little Alnus, Quercus, Betula, Carpinus, Picea and Ulmus. NAP was composed of Gramineae, Compositae, Chenopodiaceae Cyperaceae, Caryophyllaceae, Liliaceae, Umbelliferae, Artemisia, Lobelia, Rumex, Polygonum. Increase of the NAP such as Gramineae, Artemisia and Chenopodiaceae, they would mostly have been transported from the other areas because agricultural activity is impossible at Dokdo. While one reason of Pinus thunbergii decrease could be regarded as environmental change, the other reason would be lumbering of pine trees by human activity which is adapted to Dokdo environment.

• Journal of Veterinary Clinics
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• v.6 no.2
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• pp.227-259
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• 1989

Waterpepper is a weed which grows on damp soil. especially near swamps, and in shallow water of ponds and ditches. It Is widespread throughout the country In abundant colonies. In the present experiments, possible toxic effects of waterpepper were investigated in ruminants. Pour cows were fed waterpepper ad libitum or by force in the from of green forage, hay and/or powder, 8 goats were administered in the form of methanol extract, and 4 goats, crude juice, into the lumen. Clinical signs were examined as well as urinalysis, hematology, serum chemical analysis, pH/blood gas analysis and chclinesterase activities following administration of waterpepper. Six goats which were administered the methanol extract or crude juice were sacrificed for pathological examinations., In addition to the clini copathological examinations, the chemical constituents of waterpepper were qualitively analyzed from the methanol extract and the Effects of the waterpepper crude juice were examined on the motility of rabbit duodenum and uterus. It is revealed that waterpepper contains steroids, terpenoids, flavonoids, tannin and essential oils in the methanol extract and nitrates in the crude juice. The crude juice of waterpepper relaxed the rabbit uterine and duodenal smooth muscles. The constraction of duodenum by acetylcholine or BaCl$_2$ were partially inhibited by pretreatment of the crude juice. However, the relaxation of duodenum by the crude juice was not blocked by the pretreatments of phenoxybenzamlne, propranolol, cocaine, reserpine and tetrodotoxin. The constituents of waterpepper to evoke elaxation of duodenal smooth muscle were stable to heat. The cows administered waterpepper showed common clinical symptoms such as acrid expression, restlessness, dullness, inappetence, anorexia, severe diarrhea, mild bloat and left displacement of abomasum, while bloody feces was shown in a cow. The goats administered the mothanol extract showed common clinical signs such as acrid expression, restlessness, dullness, inappetence and soft feces, while bloody feces was shown in a goat, A goat adminstered the crude juice showde bloody feces and diarrhea. Respiratory rates and heart beats were increased along with diarrhea in the experimental cows. The erythrocyte counts and MCHC were decreased whereas PCV, MCV and neutrophils were increased in the cows administered waterpepper. In goats administered methanol extract, there were decreases in erythrocytes, PCV and hemoglobin content, and an increase in MCHC. The goats ingester with the crude juice showed negligible changes in hematologic values compared with control group which was administered the same amount of water instead of the crude juice. The contents of serum calcium, Inorganic phosphorus, magnesium, Iron, glucose, cholesterol, total protein, triglycerides and phospholipids were tended to decrease in cows. In goats serum iron, glucose, triglycerides, cholesterol, BUN and phospholipids content were decreased while the content of sodium and chloride were increased after administration of the methamol extract The goats ingested with the crude juice did not show significant changes in serum chemical analysis. Even though there were some pathological findings such as hyperemia in the small intestines and kidneys and swelling of liver parenchymal cells, the values of serum AST, ALT, LDH, alkaline phosphatase, total bilirubin and creatinine did not change significantly. While proteins, hemoglobin and blood were detected in the urine of cows, urine pH, ketone bodies, glucose, bilirubin and urobilinogen content were normal or undetected. There were no significant changes in pH/bolld gas analysis data of cows and cholinesterase activities of plasma and erythrocytes of cows and goats ingested with waterpepper or the methanol extract. It is concluded that waterpepper irritates the gatrointestinal system, causes abdominal pain, relaxes the gastrointestinal smooth muscle and dilatates blood vessels supplied to the system. The irritation and relaxation may lead to abnormal fermentation, maldigestion and malabsorption of nutrients and result in diarrhea, body feces, mild bloat and left displacement of abomasum.