• Title/Summary/Keyword: exotic species

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A Study on the Ecological Restoration Strategies for the Disturbed Landscapes (경관훼손지의 생태적 복구방안에 관한 연구)

  • Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.1 no.1
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    • pp.28-44
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    • 1998
  • This study was conducted to suggest the ecological restoration strategies for the disturbed landscapes by theoretical study. Especially, it is aimed to suggest three objectives for restoration by using native plants ; (1) prevention or reduction of wind and water erosion, (2) provision of food and cover for variety of animal species, (3) improvement of the visual or aesthetic quality of disturbed sites. The main results were summarized as follows. 1. Cooperation between restoration ecologists and restoration practitioners is needed to delineate a scientific approach to restoration ; (1) Being aware of published literature that describes similar work and/or establish general principles. (2) Preparedness to carry out proper experiments to test ideas. (3) Preparedness to monitor fundamental parameters in a restoration scheme. (4) Providing information about the behavior of species. (5) Publish results. 2. There are three models of succession in theories of plant succession. The tolerance and facilitation models were recommended to ecological restoration. The inhibition model applies in most secondary succession, but the actual species which are introduced first may inhibit the germination and growth of slower-growing species, or they may prevent the growth of other species whose propagules arrive later. 3. The objectives of erosion control, wildlife habitat provision, and visual quality improvement are not mutually exclusive. However, many revegetation practices in the past have emphasized one of these aspects at the expense of the others. 4. A native plant community can be the model of ecological restoration. By stylization/abstraction of native plant community, trying to learn the most essential characteristics of community types - environmental factors ; dominant, prevalent, and "visual essence" species composition - in order to use such information in restoration. 5. After developing mass/spaces plan, match plant communities to the mass/space plan. In utilizing community grouping, there needs aesthetic ability to understand design elements. 6. Several hydrophytes such as Pennisetum saccharifluous, Themeda triandra, Cirsium pendulum show relatively good germination rates. In case of mesophytes and xerophytes, Arundinella hina, Artemisia princeps, Oenothera odorata and legumes seem to have quick-germinating abilities at barren sites. Pinus thunbergii, Rhus chinensis, Evodia daniellii, Alnus firma and Albizzia julibrissin can be considered as "late succession" woody plants because they show low germinating rates and slow growing habitat. 7. The seeds used for restoration should be collected within a certain radius of where it will be planted. Consideration in genetic issues in the collection and use of germplasm can increase the odds for successful restoration efforts. 8. The useful model in the "drift" pattern occurs so abundantly in naturally evolving landscapes. As one species diminishes in density, a second or third species are increased. Thus, dynamic interactions between species are created. Careful using of "drift phenomenon" in planting was recommended. 9. Virtually no stand of vegetation today is immune from the introduction and/or spreading of exotic species. Therefore, the perpetuation of a restored sites requires conscious monitoring and management. Thus, management would be the most important process in ecological restoration. 10. In order to keep the sites "natural", alternative management strategies would be applied in management ; Atenative management strategies are decelerating successional process, accelerating successional processes or modifying species composition. As management tools, mechanical, chemical, biological or environmental factor manipulation, e.g., fire could be used.

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Variability in Specific Leaf Weight in Mulberry Germplasm and Its Inheritance Pattern

  • Sarkar, A.;Mogili, T.;Chaturvedi, H.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.1
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    • pp.69-73
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    • 2003
  • Specific leaf weight (SLW), defined as the mass of tissue per unit leaf area has been found to be an important physiological parameter as it indicates the relative thickness of leaves. Greater SLW provides more photosynthetic potential per unit area of leaf and hence it is frequently been considered as correlated with photosynthesis in several plant species. Collections of 165 mulberry (Morus sp.) germplasm accessions, both Indian and exotic in origin were evaluated for their variability with respect to SLW. The mean specific leaf weight ranged from 35.3 to $72.3 g/m^{-2}$. The distribution of SLW was found to be normal. High heritability (97.08%) and a small difference between genotypic and phenotypic variance demonstrates the genetic control over SLW. Significant heterotic effect with respect to SLW was observed in crosses when parents with high and low SLW were chosen.

A Survey of Sarcocystis infections in slaughtered cattle in Korea (도축우(屠畜牛)에 있어서 주육포자충(住肉胞子蟲) 감염실태조사(感染實態調査))

  • Kang, Yung-bai;Kim, Sang-hee;Wee, Sung-hwan
    • Korean Journal of Veterinary Research
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    • v.28 no.2
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    • pp.387-390
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    • 1988
  • A preliminary survey of Sarcocystis species in the slaughtered cattle in Seoul was undertaken during October through December 1987, using digestion diagnostic technique for the heart muscle specimens digested in 0.5% trypsin solution. Results indicated that 41.5% of 159 bovine hearts were infected with Sarcocystis proliferative forms. High frequencies in the exotic dairy cattle(42.2%) and the Korean native cattle(41.7%) were noticed in comparison with low frequency in the cross breed(25.0%). No differences were indicated between the sexes of the host animals, although an age difference was noticed as 48.9% in cattle older than four years in comparison with 39.0% and 37.1% in younger than two years and in two to four years, respectively.

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The Inhibition Effect of Expansion of the Exotic Species caused by Ecological Stream Restoration (생태적 하천복원이 가져온 외래종 억제 효과)

  • Lee, Chang-Seok;Cho, Yong-Chan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1130-1134
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    • 2007
  • 콘크리트 호안블럭으로 처리된 하천의 제방 단면에 드릴로 구멍을 낸 후 하천변에 전형적으로 생육하는 갯버들과 버드나무를 도입하며 부분적 복원을 실행한 후 그 효과를 외래종 억제 측면에서 검토하였다. 복원 후 4년 경과 후 버드나무의 높이는 4cm 이상으로 자랐으나 갯버들의 높이는 2m 이내로 낮았다. 버드나무가 식재된 부분에서 외래종인 단풍잎돼지풀의 식피율은 5% 이내로 낮았으나 갯버들이 식재된 지소에서는 20%수준을 유지하였다. 복원된 지소와 미복원 지소에서 수집된 식생자료를 서열법으로 처리한 결과, 양지소는 서로 분리되어 서로 다른 종 조성을 유지하고 있음을 알 수 있었다. 갯버들, 버드나무 및 단풍잎돼지풀의 지소별 출현 현황을 비교한 결과, 버드나무와 단풍잎돼지풀은 서로 대조적인 출현 추세를 보였지만 갯버들과 단풍잎돼지풀의 출현 현황은 그러한 경향이 약했다. 종 다양성은 이러한 결과로부터 하천복원에서 큰키나무 도입의 필요성을 알 수 있었다.

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Fuzzy FMECA analysis of radioactive gas recovery system in the SPES experimental facility

  • Buffa, P.;Giardina, M.;Prete, G.;De Ruvo, L.
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1464-1478
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    • 2021
  • Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic application allow to show that Fuzzy Risk Priority Number is able to enhance the focus of risk assessments and to improve the safety of complex and innovative systems such as those under consideration.

Insects Diversity by Habitat Types in Middle Inland of DMZ, Korea (DMZ 중부지역의 서식유형에 따른 곤충다양성)

  • Park, Soeng-Joon;Lee, Jung-Hyo;Oh, Seung-Hwan
    • Korean Journal of Environment and Ecology
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    • v.26 no.5
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    • pp.682-693
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    • 2012
  • This study was intented to understand the insects diversity and forest in DMZ, and provide data and information required to preserve living creatures and geological management, and basic information for the management and preservation policies. This study has surveyed insects diversity by habitat types in Middle Inland of DMZ, Korea from 15 to 19 September, 2009. Totally there were 128 species belonging to 53 families of 10 orders, among them, 7 endermic species, 3 management of exotic species and 25 designated species were showed. The highest was 26 species of Hemiptera(20.31%) and then next turn are 22 species of Coleoptera(17.19%) and 20 species of Hymenoptera(15.63%) respectively. Dominant species are Ceracris nigricornislaeta (Bolivar)(0.152) in S1, Menida violacea Motschulsky(0.218) in S2, Stomorhina obsoleta (Wiedemann)(0.171) in S3, Ducetia japonica (Thunberg)(0.212) in S4, Oedaleus infernalis Saussure(0.178) in S5, Sepedon aenescens Wiedemann(0.268) in S6, Adelphocoris triannulatus (Stal)(0.257) in S7 and Ricania taeniata Stal(0.150) in S8 site. The diversity(H') and richness(RI) of insects at survey area as S2(H'=3.461, RI=9.64), S3(H'=3.457, RI=9.18) and S1(H'=3.447, RI=8.88) were higher than in the others and the lowest in S8(H'=2.790, RI=5.341). But the highest species evenness index(EI) occurred in S8(0.985).

Chemical Water Quality and Fish Community Characteristics in the Mid- to Downstream Reach of Geum River (금강 중.하류역의 이.화학적 수질특성 및 어류 군집특성)

  • Han, Jeong-Ho;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.31 no.3
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    • pp.180-188
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    • 2013
  • The objectives of the study were to analyze chemical water quality and fish community structures in the downstreams of Geum River during 2004~2005. Water quality parameters showed that ionic dilution was evident during July~August due to a rainfall and river runoff by Asian monsoon. Mean concentrations of BOD showed a seasonal variation and were greater in the downstream than in the midstream. The total number of fish species observed was 34 (11 families) and 30.3% of them was Korean endemic species. The dominant species with > 20% of the total were Zacco platypus (25.9%) and Microphysogobio jeoni (21.5%) in the river. Exotic species observed was only one species, Carassius cuvieri with relative abundance of 1.8%. According to the structure analysis of fish community, species richness index was highest (3.714) in S6 and lowest in S4 (1.961), while species diversity index was highest in S2 (1.01) and lowest in S5 (0.507). Tolerant species dominated the fish community (49%), and the sensitive species were rare (4.4%), indicating a biological degradation of ecosystem. In the mean time, omnivore species was composed of 49% in the fish community and insectivore species was nearly same with the proportion of the omnivores.

Pull-out Strength Characteristics of Revegetation Species Root used for Forest Road Slope (임도사면 녹화식물뿌리의 인발강도특성에 관한 연구)

  • Ji, Byoung Yun;Jung, Do Hyun;Chun, Kwon Suk;Kim, Jong Yoon
    • Journal of Korean Society of Forest Science
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    • v.95 no.1
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    • pp.45-49
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    • 2006
  • The objective of this study is to offer a basic information to select the plant species for environmentally friendly forest road by quantifying the pull-out strength by 18 species used for a revegetation of forest road slope. In the investigation of the root depth growth during 17 months, Indigobush amorpha showed maximum depth of 34.0 cm and perennial ryegrass showed minimum depth of 17.7 cm among all species. The pull-out strength by herb species was $0.054ton/m^2/plant$ for exotic species, $0.085ton/m^2/plant$ for indigenous species, and by shrub species was $0.049ton/m^2/plant$. There were no large difference among herb species in pull-out strength, but shrub species were approximately 9 times stronger than herb species. Thus, for maximizing tightening effect and use of inner soil space. The mixed seeding using herb for erosion control and shrub for shallow failure protection would make up optimal revegetation of forest road slope.

Ichthyofauna and Fish Community Structure in Upper Reach of the Nakdong River, Korea (낙동강 상류의 어류상과 군집 구조)

  • Chae, Byung Soo;Kim, Sang Ki;Kang, Yeong Hoon;Heo, Nam Soo;Park, Jae Min;Ha, Heon Uk;Hwang, Ui Wook
    • Korean Journal of Ichthyology
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    • v.27 no.2
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    • pp.116-132
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    • 2015
  • Freshwater fish fauna and community structure were investigated at 44 stations in upper reach of the Nakdong river, Korea from March to October 2014. During the surveyed period 42 species and 4 types belonging to 34 genera and 14 families were collected. In this collection fishes of Cyprinidae were 17 species and 4 types, most numerous possessing 43.2% of all. There were 17 Korean endemic species including Kichulchoia multifasciata, 3 endangered species such as Koreocobitis naktongensis, Lethenteron reissneri and Brachymystax lenok tsinlingensis and 2 exotic species such as Lepomis macrochirus and Micropterus salmoides. Fish species transferred from other native rivers were 9 species including Hemibarbus mylodon, Coreoleuciscus slpendidus Han river type, Opsariichthys uncirostris amurensis, Iksookimia koreensis and Liobagrus andersoni. Dominant species based on the number of individuals was Rhynchocypris oxycephalus (21.44%) and sub-dominant species were Zacco koreanus NE type (18.55%). The community analysis revealed that the structure of fish community in upper reach of the Nakdong river was very stable and diverse in having diversity 1.101, evenness 0.670, dominance 0.400 and species richness 4.454. Fish community was divided into 5 groups based on similarity indices among surveyed stations such as uppermost, upper I, upper II, mid-upper, middle reach group.

Ichthyofauna and Fish Community Structure in the Hoecheon Stream and Some Adjacent Tributaries of the Nakdonggang River, Korea (회천 및 인접 소하천들의 어류상과 군집 구조)

  • Chae, Byung Soo;Kim, Sang Ki;Kang, Yeong Hoon;Heo, Nam Soo;Yoo, Dong Uk;Park, Jae Min;Ha, Heon Uk
    • Korean Journal of Ichthyology
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    • v.29 no.3
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    • pp.205-217
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    • 2017
  • Fauna of freshwater fish and community structure were investigated at 24 stations in the Hoecheon Stream and some adjacent tributaries of the Nakdonggang River, Korea from July 2016 to August 2017. During the period 42 species and 4 types belonging to 32 genera and 11 families were collected. In this collection fishes of Cyprinidae were 24 species and 4 types, most numerous possessing 59.1% of all. There were 16 Korean endemic species including Acheilognathus yamatsutae and Odontobutis platycephala, 3 endangered species such as Pseudobagrus brevicorpus and Koreocobitis naktongensis (rank I) and Culter brevicauda (rank II) and 2 exotic species such as Micropterus salmoides and Lepomis macrochirus. Fish species transferred from other native rivers were 4 species including Opsariichthys uncirostris amurensis, Hemiculter eigenmanni, Odontobutis interrupta and Tridentiger brevispinis. Dominant species was Zacco koreanus NS type (19.2%) and sub-dominant species was Z. platypus R type (16.1%). The structure of fish community in the Hoecheon Stream was very stable and diverse in having diversity 2.91, evenness 0.77, dominance 0.35 and species richness 4.67. Fish community was divided into 4 groups such as upper, middle, midlower and lower reach group based on similarity among surveyed stations.