• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.286-294
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• 2017

Development of transportation is rapidly reducing the barriers between countries, but this is causing the easier migration of species than the past. Typically, exotic species are imported for the purpose of food, leather, and pets. However, it has been introduced into the wild through artificially or naturally paths, and recently they are become a main cause of ecosystem disturbance. In this study, we investigated exotic turtle species introduced into the wild and analyzed their distribution characteristics. As a result of filed surveys, totally 4 genus 8 species 62 individuals of exotic turtles were found from 126 reservoirs in Gangwon-do and Gyeongsangnam-do, South Korea. In particular, Trachemys scripta elegans showed relatively high frequency than other turtle species and the natural reproduction of T. s. elegans was confirmed in some areas. On the other hand, the frequency of discovery of exotic turtles except T. s. elegans was relatively low, and the range of the areas was limited. Especially, exotic turtles except T. s. elegans were mainly found in public places such as reservoirs in the park. As a result of analyzing the distribution characteristics of exotic turtles using geographic information system, the turtles' distribution showed a high correlation with the artificial factor such as "urban". In this study, we identified the distribution characteristics of exotic turtles in the Korean wild, and these results will be important data for understanding status the and establishing effective management methods for exotic species.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.2
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• pp.68-74
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• 2009

Polycyclic aromatic hydrocarbons (PAHs), one of ubiquitous organic pollutants in marine environments, are major toxic components of petroleum and are produced during the incomplete combustion of organic materials. As shipyards are located inside of natural or artificial semi-enclosed bay, even a relatively weak environmental disturbance by ship-building activity can cause severe damage to marine ecosystem in the bay. Many studies of pollution in shipyard area have been focused on the antifouling agent, like tributyltin. This study aimed to investigate the effect of ship-building activity on PAH contamination. Total PAHs concentration was higher nearby and inside shipyard area than outside, implying that shipyard could be one of major source area of PAH contamination to pose harmful effects to surrounding environments. Through PAH profile and source recognition index, the source of PAHs inputs in this area was estimated to originate from both petrogenic and pyrogenic origin. PAH levels showed a significant correlation with total butyltins, indicating that ship-building activity influenced PAH concentration and distribution. Vertical distribution of PAHs historically confirmed the correlation between shipbuilding activity and PAHs contamination.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.327-349
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• 2010

This study was carried out to investigate the distribution of vascular plants and their use from 2007 to 2009 in Mt. Unmum(Cheongdo-gun, Gyeongsangbuk-Do). The vascular plants were summarized as 605 taxa including 98 families, 304 genus, 514 species, 3 subspecies, 68 varieties, and 20 forma. Among the investigated 605 taxa, 21 rare and endangered plants, 29 Korean endemic plants were included. Based on the list of specially designated plants by Ministry of Environment, 70 taxa included Iris odaesanensis and Gastrodia elata were recorded in the investigated area. The naturalized plants were identified as 23 taxa and the percent of naturalized index(NI) was 3.8% of total 605 taxa vascular plants. Usage of 605 taxa were consists of 225 taxa(37.2%) of edible plants, 191 taxa(31.6%) of medicinal plants, 64 taxa(10.6%) of ornamental plants, 46 taxa(7.6%) of pasture plants, 18 taxa(3.0%) of timber plants, 14 taxa(2.3%) of fiber plants, and 3 taxa(0.5%) of industrial plants. To management of natural resource, we suppose that it is required to establish an ecological learning area to minimize human disturbance and an effective managemet strategy by continuous monitoring for ecosystem change.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.267-283
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• 2011

Endangered species designated by The Ministry of Environment in region of Naejangsan National Park were found Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko, Iris koreana Nakai, Cymbidium macrorrhizum Lindl and Vexillabium yakushimensis (Yamam.) F.Maek.(4 taxa). The floristic special plants were recorded to a total of 159 taxa; that is, class I species (91 taxa) were containing as Chloranthus fortunei (A.Gray) Solms, Vicia anguste-pinnata Nakai and Euscaphis japonica (Thunb.) Kanitz, etc, class II species (17 taxa) were Pseudostellaria coreana (Nakai) Ohwi, Dryopteris expansa (C.Presl) Fraser-Jenkins et Jermy and Gymnocarpium dryopteris (L.) Newman, etc, class III species (32 taxa) were containing; Cirsium setidens (Dunn) Nakai, Parasenecio pseudotaimingasa (Nakai) B.U.Oh and Saussurea eriophylla Nakai, etc, class IV species (9 taxa) were Deutzia paniculata Nakai, Carex ligulata Nees and Thuja orientalis L., etc, and class V species (10 taxon) were Orobanche filicicola Nakai, Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko and Lycoris sanguinea var. koreana (Nakai) T.Koyama, etc. Endemic species of korea were identified 40 taxa such as Broussonetia kazinoki var. humilis Uyeki, Pseudostellaria coreana (Nakai) Ohwi and Silene seoulensis Nakai, etc. Plant species designated as Natural Monument were 2 species that Daphniphyllum macropodum forest(No. 91) and Torreya nucifera forest(No. 153) receive protection. The naturalized plants were identified 30 taxa; Fallopia dumetorum (L.) Holub, Persicaria orientalis (L.) Spach and Rumex crispus L., etc. Among them the ecosystem disturbance wild plants was not discovered.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.142-156
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• 2020

This study surveyed Gyeongan Stream, a tributary of the Han River Drainage System, from April to October 2017 to investigate the characteristics of fish communities. The survey collected 40 species of 11 families from 48 survey stations using kick nets and cast nets. The dominant and subdominant species were Zacco platypus (48.0%) and Rhynchocypris oxycephalus (17.7%), respectively. The next most abundant species were Pungtungia herzi (6.8%), Z. koreanus (5.0%), Carassius auratus (4.3%), Squalidus gracilis majimae (2.7%), and Rhodeus notatus (2.5%). Among the fish collected, 14 species (35.0%) were Korean endemic species, and the exotic species were Micropterus salmoides, Lepomis macrochirus, and Cyprinus carpio (Israeli type). The land-locked species were Plecoglossus altivelis, Rhinogobius brunneus, and Cottus koreanus, while the species sensitive to climate change was C. koreanus. The community analysis showed that the dominance was higher at the uppermost stream station, whereas diversity and abundance tended to be lower at the upstream station and higher toward the downstream station. The community structure was largely divided into rivers (uppermost stream, upstream, and middle-lower stream) and lake. The river health was mostly good (23 stations, 47.9%) and fair (15 stations, 31.3%). Comparison with past surveys showed that 12 species identified in the past surveys did not appear in this survey; nine species appeared for the first time in this survey; and the ecosystem disturbance species - M. salmoides and L. macrochirus - tended to spread more widely gradually.

• Korean Journal of Plant Taxonomy
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• v.46 no.1
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• pp.83-116
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• 2016

This study was carried out to investigate the flora and vegetation of Yokjido Island in Tongyeong-si, Korea. Vascular plants collected six times (from March of 2015 to January of 2016) were identified as 547 taxa in total, including 113 families, 354 genera, 487 species, four subspecies, 50 varieties, four forms and two hybrids. The first records from this region contained 314 taxa. In the flora of this area, endemic Korean species numbered eight taxa, and the red list of vascular plants according to the IUCN valuation basis numbered six taxa. In addition, 86 taxa of floristic regional indicator plants specially designated by the Ministry of Environment are included. Among the species investigated in this survey, 99 taxa were identified as specific species bio-geographically as compared floras of other terrestrial regions; 97 taxa of plants in southern areas and two taxa of limited distribution plants on the Korean Peninsula. In all, 74 naturalized plants were recorded in the investigated area. Samples of the forest vegetation of Yokjido Island were mainly classified as Pinus thunbergii community and the Alus firma community. Vertical structures of the communities were stable, and a DBH-class analysis showed that the dominant tree species would be maintained. If disturbance factors such as thinning could be halted, the composition of woody species and herbaceous species would change.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.435-449
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• 2017

A floristic study on the vascular plants from Mt. Seounsan region, which ranges from Seoun-myeon, Anseong-si, Gyeonggi-do to Baekgok-myeon, Jincheon-gun, Chungcheongbuk-do, was conducted 9 times in total, from April 2014 to October 2015. Based on the voucher specimens, it was revealed that the vascular plants in this region comprised 501 taxa: 97 families, 306 genera, 439 species, 5 subspecies, 51 varieties, and 6 forma. Among these plants, 185 taxa were recorded for the first time from this region. 8 Korean endemic species including Asarum patens (K.Yamaki) B.U.Oh, Scutellaria insignis Nakai, and Weigela subsessilis (Nakai) L.H.Bailey were found in this region. 5 taxa of rare plants designated by the Korea Forest Service, including Iris ruthenica KerGawl., Leontopodium leontopodioides (Willd.) Beauverd, and Tricyrtis macropoda Miq., were also found. 11 taxa of floristic regional indicator plants in the $3^{rd}$ to the $5^{th}$ degrees were identified. In addition, 46 taxa of naturalized plants were recorded, and 2 taxa of ecosystem disturbance plants, which were Ambrosia trifida L. and Aster pilosus Willd., also found.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1561-1569
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• 2006

Denaturing gradient gel electrophoresis (DGGE) is one of the most frequently used methods for analysis of soil microbial community structure. Unbiased PCR amplification of target DNA templates is crucial for efficient detection of multiple microbial populations mixed in soil. In this study, DGGE profiles were compared using different pairs of primers targeting different hypervariable regions of thirteen representative soil bacteria and clones. The primer set (1070f-1392r) for the E. coli numbering 1,071-1,391 region could not resolve all the 16S rDNA fragments of the representative bacteria and clones, and moreover, yielded spurious bands in DGGE profiles. For the E. coli numbering 353-514 region, various forward primers were designed to investigate the efficiency of PCR amplification. A degenerate forward primer (F357IW) often yielded multiple bands for a certain single 16S rDNA fragment in DGGE analysis, whereas nondegenerate primers (338f, F338T2, F338I2) differentially amplified each of the fragments in the mixture according to the position and the number of primer-template mismatches. A forward primer (F352T) designed to have one internal mismatch commonly with all the thirteen 16S rDNA fragments efficiently produced and separated all the target DNA bands with similar intensities in the DGGE profiles. This primer set F352T-519r consistently yielded the best DGGE banding profiles when tested with various soil samples. Touchdown PCR intensified the uneven amplification, and lowering the annealing temperature had no significant effect on the DGGE profiles. These results showed that PCR amplification bias could be much improved by properly designing primers for use in fingerprinting soil bacterial communities with the DGGE technique.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.253-261
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• 2007

Molecular and cultivation techniques were used to characterize the bacterial communities of biobead reactor biofilms in a sewage treatment plant to which an Aerated Up-Flow Biobead process was applied. With this biobead process, the monthly average values of various chemical parameters in the effluent were generally kept under the regulation limits of the effluent quality of the sewage treatment plant during the operation period. Most probable number (MPN) analysis revealed that the population of denitrifying bacteria was abundant in the biobead #1 reactor, denitrifying and nitrifying bacteria coexisted in the biobead #2 reactor, and nitrifying bacteria prevailed over denitrifying bacteria in the biobead #3 reactor. The results of the MPN test suggested that the biobead #2 reactor was a transition zone leading to acclimated nitrifying biofilms in the biobead #3 reactor. Phylogenetic analysis of 16S rDNA sequences cloned from biofilms showed that the biobead #1 reactor, which received a high organic loading rate, had much diverse microorganisms, whereas the biobead #2 and #3 reactors were dominated by the members of Proteobacteria. DGGE analysis with the ammonia monooxygenase (amoA) gene supported the observation from the MPN test that the biofilms of September were fully developed and specialized for nitrification in the biobead reactor #3. All of the DNA sequences of the amoA DGGE bands were very similar to the sequence of the amoA gene of Nitrosomonas species, the presence of which is typical in the biological aerated filters. The results of this study showed that organic and inorganic nutrients were efficiently removed by both denitrifying microbial populations in the anaerobic tank and heterotrophic and nitrifying bacterial biofilms well-formed in the three functional biobead reactors in the Aerated Up-Flow Biobead process.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.370-375
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• 2013

Exotic species in aquatic ecosystem generate various problems domestically as well as globally. Largemouth bass (Micropterus salmoides) which is a well-known exotic species globally, acts as a substantial disturbance factor on the native fish communities in Korea due to the high predation pressure and hence designated as a ecologically harmful species by Ministry of Environment. In this study, we investigated the impact of largemouth bass on Korean native fish population, crucian carp (Carassius auratus), to identify responses of the prey fish. Two fish species were collected at seven reservoirs distributed at the Nakdong River catchment area, and changes in length-frequency and length-weight relationship (LWR) were analysed depending on existence of large-mouth bass. At bass absent sites, ratio of under age 1 year individuals were small, and over age two years were dominant. Conversely, normal length-frequency distribution pattern was identified at bass absent sites. The LWR of crucian carp (fish smaller than total length of 160 mm were only considered as it is frequently consumed by bass predation) was different depending upon bass existence. The value of parameter b at bass absent reservoirs was 2.909, which was smaller than that of bass present reservoirs, 3.100. Our results imply that crucian carp at bass present reservoirs presented a different strategy to survive from predation by bass, through relatively rapid growth. We propose that other native species might have similar growth strategies like crucian carp.