• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.363-373
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• 2021

An ecological niche is defined as the specific role of a species influenced by time, space, and other resources. By investigating overlaps between ecological niches of different species, we could estimate the degrees of interspecific competition. Such studies often use geographic information systems (GIS) to discover niche overlaps between species. In this study, we used GIS to estimate the spatial niches of two Korean frog species(Pelophylax nigromaculatus and P. chosenicus). This enabled us to predict their geographic distributions in order to identify their coexistence regions and distribution patterns. The results confirmed that altitude was an important variable for predicting their distribution, with a correlation with their climatic range. Spatial distributions of the two frog species were highly overlapped, as the distribution range for P. nigromaculatus included most of the range of P. chosenicus, showing a sympatric distribution pattern. Within the coexisting regions, however, the presence sites for the two species did not overlap, implying weak competition. To confirm the principal factors influencing their competitive relationship and reasons for their sympatric distribution pattern, we need more detailed in-depth studies on the diverse environmental variables within the regions where the two species coexist. By doing so, we would be able to identify various mechanisms for avoiding competition in sympatric frog species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.214-222
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• 2006

Dominant species of macrobenthos were analyzed based on differentiation of three distinct methods: the density based method, the biomass based method and LeBris method, by considering the frequency of occurrence using quantitative data collected over 5 years (1993-1998) at 21 stations in Chonsu Bay. Sedimentary environments as well as species composition and diversity showed the spatial and temporal distribution patterns. The ranks of dominant species as determined by the density based method were more similar to the results by the LeBris method than to those from the biomass based method. Considering the temporal variation, LeBris method were more efficient than any other methods for the determination of dominant species in Chonsu Bay. Lumbrineris longifolia, Theora fragilis, and Moerella jedoensis were recognized by all three methods. A one-way analysis of variance indicated spatial distributions patterns among most of the dominant species. These species showed positive correlations to sedimentary parameters such as mean grain size. However, T. fragilis and Paraprinospio pinnata showed the temporal patterns in their distribution, and were also correlated to the benthic environment, organic content and dissolved oxygen. Some dominant species, e.g., T. fragilis, S. scutata, G. gurjanovae proved to be useful benthic indicators based on the environmental variations determinated by long-term benthic ecological monitoring in Chonsu Bay.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.626-639
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• 2017

Based on an ecological monitoring in a Korean stream (Gapyeong), Habitat Suitability Index (HSI) of nine fish species was developed for three physical habitat factors : current velocity, water depth and substrate. The species were chosen based on their abundance and frequency in the fish community of the Gapyeong stream. The Weibull model was used as the probability density function to analyze the distribution and number of each fish species according to the three identified physical factors, which showed good results. This HSI equation has advantages because it statistically expresses habitat preferences of fish species simply and clearly. From that, we can quantitatively deduce the central tendency and variation of environmental factors for fish distribution. The selected fish species showed different preferences for each habitat factor respectively. Although there are some exceptions, the distribution and abundance of individual species of nektonic fish (Zacco koreanus, Zacco platypus, Microphysogobio longidorsalis and Pungtungia herzi) were positively skewed to deep water and fine substrate while riffle-benthic fish (Koreocobitis rotundicaudata and Coreoleuciscus splendidus) were normally distributed at the shallow and coarse substrate zone. It seems that the species showing the positively skewed distribution to the current, Z. koreanus, Z. platypus, M. longidorsalis and P. herzi have adapted themselves to the fast current and have expanded their niche.

• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.339-348
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• 2000

This study was conducted to investigate the distribution pattern of plants on the streamside of Goggyochun, and to survey the distribution of heavy metal-contaminated soils and plants. A total of 11 survey sites were selected along the Goggyochun during the period of between June and September 1999. The wet land plants were composed of 44 species. The most frequently occurring species in the study sites were Rumex crispus, Persicaria hydropiper, Cyperus amuricus and Setaria viridis, and among them the Humulus japonicus, Erigeron canadensis and Phragnites communis species were dominants of the community. Analysis of soil properties showed that organic matter and clay contents were higher in the upstream region while sand content was higher in the downstream region. The pH and the organic matter contents of soils were at range of 6.70-9.94 and 2.39-15.16% respectively. The average contents of Pb and Cd in soils were 11.96mg/kg and 1.64mg/kg respectively, and these values were higher as compared with those of ordinary soil in Korea. The average contents of Zn and Pb in Persicaria hydropiper were 8.30mg/kg and 7.38mg/kg respectively, and these values were higher than other plants. The distribution of heavy metals in plants varied in accordance with the species regardless of the sites.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.144-152
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• 2021

Sanankerto is one of pilot projects for tourism villages in Indonesia due to its natural tourism potential with a 24-ha bamboo forest located in Boon Pring Andeman area. However, the distribution of existing bamboo has never been identified or mapped. Thus, the mana gement is facing difficulty in planning and developing tourism potential as well as spatial management in the area. Therefore, the objectives of this study were to identify and analyze the structure of bamboo vegetation in the Boon Pring Tourism village an d to perform vegetation mapping. The type of research was descriptive exploratory with a cluster sampling technique (i.e., a two-stage cluster) covering an area of ± 10 ha. Bamboo vegetation analysis was performed by calculating diversity index (H'), evenness index (E), and Species Richness index (R). Data were collected through observation and interviews with local people and the manager to determine zonation division. Mapping of bamboo vegetation based on zoning was processed into thematic maps using ArcG is 10.3. Micro climatic factors were measured with three replications for each sub -cluster. Data were analyzed descriptively and quantitatively. Nine species of bamboo identified. Diversity, evenness, and species richness indices differed at each location. Activities of local communities, tourists, and manager determined the presence, number, and distribution of bamboo species. These bamboo distribution maps in three zoning (utilization, buffer, and core) can be used by manager for planning and developing natural tourism potential.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.512-522
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• 2012

This study is focused on fish fauna and distributional features along with physical gradients and stream orders in the Tamjin River basin, Korea. Fish sampling and investigation were conducted for 2 years from 2009 to 2010. Total number of fish species collected were 47 species of 16 family. The group of cyprinidae was mostly abundant. Both fish abundance and biotic index were declined with increasing altitude and longitudinal distance from the river mouth. Two species of Zacco temminckii and Pungtungia herzi were prevalent in most of sampling sites and showed no altitudinal and longitudinal differences. Most other species, however, were spatially restricted to specific regional altitudes. Several species including Zacco platypus, Squalidus gracilis majimae and P. herzi were broadly distributed from river mouth to 50 km. Eight species including Z. temminckii and Rhynchocypris oxycephalus only appeared in over 10 km from the river mouth. Both Odontobutis platycephala and Pseudobagrus koreanus were classified as "upstream dewelling species" observed only in over 30 km from the river mouth. High proportion of tolerant and omnivorous species were more dominated in the downstream zone of the dam, whereas intolerant and insectivorous species were abundant in the upstream zone of the dam. The variable of stream order showed positive relationship between number of fish species and total individuals collected. Sensitive species including insectivore had a declining tendency with increasing stream order, while tolerant specie including omnivore species had relatively increased with stream order. Overall, our study suggested that fish distribution considerably depends on altitudinal gradient and longitudinal distance from the river mouth as well as physical habitat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.151-156
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• 2003

Spatio-temporal distribution of dinoflagellate cysts was monthly investigated at 6 stations in Gamak Bay, the southern Korea from April 2000 to April 2001. A total of 37 species of dinoflagellate cysts belonging to 22 genera were identified. The temporal changes of species number fluctuated with an annual mean of 8 species, 1 species at Stn. 6 in July in the middle Gamak Bay and 17 species at Stn. 2 in June southern Gamak Bay, but 11 to 20 species occurred in the northwestern Gamak Bay all the year round. The major species were Brigantedinium cariacoense, Brigantedinium simpler, Brigantedinium spp., Protoperidinium americanum, Quinquecusphix concretum, Selenopemphix quanta, Scrippsiella trochoidea, Spiniferites bulloideus, Spiniferites spp., Stelladinium reidii, Votadinium carvum, and Polykrikos sp. of kofoidii. The dominant species of dinoflagellate cysts was not evident in the over-all study areas, but in the northwestern Gamak Bay Brigantedinium spp. and Protoperidinium americanum were dominant $(50.4-76.0\%)$ during the study periods. Abundance of dinoflagellate cysts on the surface sediment in the Gamak Bay ranged from 21 cysts/g dry at Stn. 6 in July to 4,322 cysts/g dry at Stn. 4 in August with an annual mean of 688 cysts/g dry. Especially, the highest value occurred in the northwestern Gamak Bay. Heterotrophic species was more abundant than autotrophic species on the surface sediment. In particular, the former occurred in $75-94\%$ in the northwestern Gamak Bay throughout the year. The northwestern area was very different from other area in species number, dominant species and abundance of dinoflagellate cysts. It is mainly due to water stagnation and eutrophication in the area. And the seasonal abundance of dinoflagellate cysts in Gamak Bay was inversly related to water temperature.

• The Korean Journal of Soil Zoology
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• v.3 no.2
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• pp.58-62
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• 1998

To find out ant fauna in the Mt. Chiak, collection tours were taken in three courses for two years. As a result, The ant fauna of Mt. Chiak were confirmed to be 45 species belonging to 23 genera under 4 subfamilies. Among them, ten species were new to Gangweon-province and Myrmica sp. 6 was new to Korea. Ants fauna of Gangweon-province at together became 74 species under 28 genera. In Ponerinae, ants fauna have become 5 species under 4 genera, in Myrmicinae, 20 species under 13 genera, in Dolichoderinae 1 species under 1 genera and in Formicinae 19 species under 5 genera.

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.1-7
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• 2020

Cynanchum L. in the subfamily Asclepiadoideae (Apocynaceae) includes four recognized species on the Korean peninsula, two of which are native to South Korea. However, the species ranges in South Korea are poorly defined. During a field survey, we discovered C. thesioides, previously unrecorded in South Korea, in Gimpo-si, Gyeonggi-do, and found an additional population of C. chinense, for which only one population has been reported in South Korea. The two taxa are considered rare species with extremely restricted distributions in South Korea, especially C. thesioides. We provide fundamental information, including descriptions, images of the habitats and morphological characters, and a taxonomic key for identification and assessments of the conservation status of Cynanchum species in Korea.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.296-304
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• 1997

This study was conducted to analyze the distribution of anticancer medicinal plants in Chonbuk area. The major results are as follows; 1. The total number of anticancer medicinal plants were reported 40 families and 83 species. 2. The results of classfied, order Tubiflorates which took majority among others, had 4 Family respectively. 3. A number of species classified by orders are as follows; 13 genus and 13 species in Family Compositae, 6 species in Family Rosaceae, 5 species in Family Leguminosae, 4 species in Family Labiatae and Family Polygonaceae and 3 species in Family Ranunculaceae, Family Rubiaceae respectively.