• The Korean Journal of Malacology
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• v.18 no.1
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• pp.61-65
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• 2002

The chromosomes of two similar lymnaeid snail species, Austropeplea ollula from Korea and "Lymnaea"sp. introduced to Australia, were karyologically investigated by using an air-dry method. The diploid chromosome number found in A. ollula was 32, and that of "Lymnaea" sp. was 30. The mitotic chromosome complements of A. ollula were 5 metacentric, 9 submetacentric, and 2 subtelocentric pairs. "Lymnaea" sp. had 5 metacentric, 8 submetacentric, and 2 subtelocentric pairs. Austropeplea ollula is distinguishable from "Lymnaea" sp. by their chromosome numbers.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.181-188
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• 2003

In this study, soil seed and bud bank analysis were performed to abbess the mass of potential vegetation in soils less than 1 year old after covered and estimate the amount of seed bank transport through construction in urban area. The ratio of exotic species number to total species number in study sites and the landfill control site was 0.29 and 0.39, respectively. All plots pooled, mean species number and total mean seedling density per $\m^2$ in the top 10 cm of soil was 11$\pm$0 (average$\pm$S.E.) and 8037$\pm$221.Total plant seeds by artificial soil trasnsfer were estimated to be 53 thousand million $m^{-2}yr^{-1}$ in 10 cm soil depth. It reveals that soil transfer accelerates seeds and vegetation movement and makes urban vegetation mixed and common.

• Journal of Species Research
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• v.2 no.2
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• pp.127-144
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• 2013

An earthworm survey of Busan metropolitan area unearthed a dozen taxa in four families (including Enchytraeidae). Members of mostly common, cosmopolitan earthworm species-complexes were: Drawida cf. koreana Kobayashi, 1938, Amynthas cf. corticis (Kinberg, 1867), Aporrectodea trapezoides (Dug$\grave{e}$s, 1828) and Eisenia fetida (Savigny, 1826). Also found were Amynthas hupeiensis (Michaelsen, 1895), A. masatakae (Beddard, 1892) and Metaphire ryunome Blakemore, 2012 - the latter a new Korean record. New taxa are: moniligastrid Drawida songae yeongdo subsp. n.; megascolecid Amynthas carnosus roki subsp. n. which is compared to nominal taxon A. carnosus (Goto and Hatai, 1899) from Japan, to A. carnosus monstriferus (Kobayashi, 1936) stat. n. from Korea and to A. lichuanensis Wang and Qiu, 2005 stat. n. from China; plus lumbricid Eisenia japonica vaga subsp. n. deemed an objectively-based molecular taxon on its unique DNA COI gene barcode. Restoration of Eisenia xanthurus (Templeton, 1836) for E. andrei is mooted (in Appendix).

• Journal of Integrative Natural Science
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• v.16 no.4
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• pp.111-122
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• 2023

Invasive species are organisms that are introduced into places outside of their natural distribution range. The global pet trade is facilitating the introduction of invasive species into new countries and areas. Among the introduced alien species, turtles are one of the most common animal groups whether lives in wetland ecosystems, such as wetlands or reservoirs. Like other countries around the world, exotic turtles is becoming a growing concern for the wetland ecosystem in South Korea. In this study, we report new reports of subspecies of Painted turtle (Chrysemys spp.): Chrysemys picta marginata, C. p. bellii and C. dorsalis, from the reservoirs in downtown Cheongju and Gwangju, South Korea. We used morphological features, such as the characteristics of the legs, plastron, and carapace, to identify the turtles. It is assumed that all turtles were artificially released into nature. Considering the increasing number of reports on the introduction of alien invasive turtles in Korean wetlands, we recommend the formulation of an immediate and systematic management plan for pet trades and organized continuous monitoring programs.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.195-202
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• 2011

This study analyzed and modeled the relationships between the probabilities of two exotic species occurrence (i.e. largemouth bass and blue gill) and environmental factors such as climatic and geographical variables using Generalized Additive Models (GAM), Generalized Liner Models and Classification Tree Analysis (CTA). The most moderate occurrence probability of largemouth bass was predicted using GAM with an area under the curve (ADC) of 0.88 and Kappa of 0.42, while those of blue gill was suggested by using CTA with an AUC of 0.92 and Kappa of 0.44. The most significant environmental variable in terms of changes in deviance for both species was the annual air temperature for the occurrence probability. Dams had stronger effect on the occurrence of largemouth bass than blue gill. Model development and prediction for the occurrence probability of fish species and richness are necessary to prevent further spread of exotic fishes such as largemouth bass and blue gill because they can threaten habitats of native river ecosystem through various mechanisms.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.114-114
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• 2022

There are 28 families and 166 species of exotic weeds on agricultural land and among these, 23 families and 80 species of exotic weeds occur on pastures. Among them, the Solidago altissima is a perennial weed belonging to the asteraceae family and it is an exotic weed that spreads to the surrounding area using methods such as high seed production, vegetative propagation using underground rhizomes and allelochemical. Accordingly, in 2009, the Ministry of Environment designated it as an ecosystem-disrupting species. This study was conducted to obtain basic data about the effects of S.altissima derived allelochemicals on forage crops. The root of S.altissima was separated, dried in the shade and then pulverized to prepare an root powder. Powder was repeatedly extracted with methanol for 3 days and concentrated under reduced pressure to obtain an root methanol extract. Dissolve the extract in distilled water, dispense it in a separate-funnel and proceed with liquid-liquid extraction by adding equal amounts of n-haxane (Hex), chloroform (CHCI₃), ethyl acetate (EtoAC), and butanol (BuOH) in order of increasing polarity. A seed-bioassay was performed using fractions for each solvent, followed by separation and purification by silica gel column chromatography. As a result of the fraction germination test for each solvent, the IC₅₀ values using the fresh weight of each fraction were 898.3 mg L^-1, 676.3 mg L^-1, 1160 mg L^-1 and 1360 mg L^-1. CA, CB, and CC fractions were obtained through primary silica gel column chromatography that used CHCI₃ fraction. As a result of seed-bioassay using each fraction, the IC₅₀ values for the fresh weight of each fraction was 537.3 mg L^-1, 1280 mg L^-1 and 1947 mg L^-1. Based on this, 5 fractions were obtained as a result of secondary silica gel column chromatography using the CA fraction. A seed-bioassay was performed, as a result, the lowest IC₅₀ value was calculated as 226.7 mg L^-1 in the CAE fraction. Based on this, the fraction was analyzed by GC-MS. The results of this study can be used as basic research data on the effects of weeds on forage crops and allelochemicals secreted from S. altissima.

• The Korean Journal of Ecology
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• v.21 no.5_3
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• pp.603-631
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• 1998

Flora and distribution of vascular plants included introduced species of Mt. Nam park in Seoul were investigated from 1997 to 1998. The flora was composed of 112 families, 338 genera, 487 species, 1 subspecies, 60 varieties, 11 forma or 559 taca. Whole taxa of Mt. Nam calculated with the other reports were recorded 125 families, 461 genera, 832 species, 2 subspecies, 115 varieties, 14 forma or 963 taxa. Mt. nam area has lost its properties because of road and promenade construction, several park reclaimation, introduction of foreign species and exotic plants, and so on. The urbanized index (UI) was comparatively high at 18.3%. Eupatorium rugosum which shown high shade tolerance comparatively was occupied dominantly in road sides. The natural ecosystem and biodiversity of Mt. Nam were under threatened by introduced species. DBH mode of Pinus densiflora community was shown bell shape but that of Quercus mongolica was shown reverse J shape, therefore, it will be occupied in the future this area dominantly by Q. mongolica community. However the vegetation of Mt. nam park area are repressing by superior position in their growth of introduced species included R. pseudo-acacia, Ailanthus altissima and E. rugosum, etc.

• Korean Journal of Environment and Ecology
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• v.31 no.4
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• pp.397-408
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• 2017

The purpose of this study is to identify the home range and habitat using pattern of the native species, Mauremys reevesii, and the exotic species, Trachemys scripta elegans, and to analyze the mutual competition relationship of the two species. This study was conducted at the Goldfish square pond, which is located in the upper part of the valley of Cheonggye mountain from August 2, 2010 to January 30, 2011. We used the three artificially proliferating M. reevesii and three T. scripta elegans which were inhabited in the ponds and reservoirs for monitoring study after attaching the transmitter to each of them. We measured the home range and the habitat utilization radius of three individuals of each species and the environmental factors such as temperature, humidity and soil and water temperature around the Goldfish square pond. As our results, it was analyzed that the M. reevesii and T. scripta elegans have a redundant ecological positions in various aspects such as limited sunbathing places, food resource utilization, hibernation place, etc. We also found that the relatively small M. reevesii was being pushed out of the competition by the relatively big. Further investigation of food competition and habitat utilization should be necessary for these two species for the natural habitats, their home range, food competition, and habitat utilization. The result of this study will be the basic data M. reevesii's restoration project.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.305-313
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• 2002

The physico-chemical characteristics of water and sediment, and structures of vegetation of the vascular hydrophytes were investigated in the West Nakdong River. Water quality was eutrophic according to the mean values and the ranges of water properties such as pH, DO, BOD, chlorophyll a, total nitrogen and phosphate, and other nutrients. A few cases were hypereutrophic for chlorophyll a level in summer. Soil reaction was weak acid. Composition of sediment was mainly sand except in SI(Sinan chideung) of which was mainly clay, and SU(Suan chideung) of which was mainly silt. Flora of vascular hydrophyte had 26 species and 1 variety comprising 16 families. Trapa japonica was dominant species in the sites of DU(Dunchido), GA(Garak chideung) and SU. Nymphoides peltata and Hydrocharis dubia dominated in DA and SI, respectively. Species diversity and evenness were relatively high in SI and SU but dominance was high in DA. After June, water lettuce(Pistia stratiotes) and water hyacinth(Eichhornia crassipes) were flowed from tributary to the river. Standing crop of macrohydrophytes was high in DA from April to August, but it showed maximum standing crop (445g·dw/㎡) in DU after disturbance by explosive growth of exotic plants in October. In comparison with those in 1985, total productivities in DU and GA decreased to 33.5%, and the reduction ratio of dominant species, Trapa japonica was 56.7%. Najas marina, N. minor, Myriophyllum spicatum and Nymphoides indica have disappeared ever since the Nakdong barrage was constructed in the Nakdong river. They were divided into three groups (GA-SU-DU, DA, SI) by cluster analysis. Introduction of the exotic species in this river caused decreasing of endemic plants including endangered species Euryale ferox and rare species Hydocharis dubia, and food plants for waterfowl such as Trapa japonica, Vallisneria asiatica and Potamogeton crispus.

• Journal of Forest and Environmental Science
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• v.21 no.1
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• pp.34-58
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• 2005

This study was executed to find out how to improve the planting and use of landscaping plants in Weonju and Hoengseong. 1. The number of street trees were 22,068 and the species number were 10 species in Weonju in 2004. The major species of street trees were Ginkgo biloba(58%), Prunus sargentii(15%), Zelkova serrata(9%), Prunus armeniaca var. ansu(8%), and Acer palmatum(6%). The ratio of native species versus exotic were 50:50. In Hoengseong, the number of street trees was 13,500 and the species number were 15 species. The major species of street trees were Prunus sargentii(42%), Ginkgo biloba(23%), Acer triflorum(12%), Prunus armeniaca var. ansu(6%), and Prunus mume(4%). The ratio of native species versus exotic were 67:33. The species of which planting frequency within two areas was very high were Ginkgo biloba and Prunus sargentii. 2. It is necessary to select tree species suitable for the characteristics of the locality and to raise distinctive street trees that contribute to the tourist industry. For the purpose, the appropriate street trees in two areas are Cornus controversa, Quercus aliena, Zelkova serrata, Prunus padus, Sorbus alnifolia, Sorbus comixta, Albizzia julibrissin, Acer triflorum, Styrax japonica, Chionanthus retusus, Celtis sinensis, Prunus yedoensis, Malus sieboldii, Crataegus Pinnatifida, Prunus armeniaca var. ansu and Pyrus pyrifolia etc.. 3. Appropriate pruning adds to the aesthetic and prolongs the useful life, it also requires less managing of insects and diseases to maintain good healthy of street trees. Street trees were not properly pruned due to electric lines and shortage of pruning information. The pruning was controlled by Korea Electric Power Co, which has no pruning information. Pruning must be maintained by a professional landscape company to maintain good shape such as with Bonsai. The shrubs planting zone between street trees and other trees, and preservation plates were established for healthy of street trees. They have to be repaired and maintained well to keep better environmental conditions. The proper fertilization, the control of pests and diseases, the installation of drainpipe and the use of soil brought from another place were needed to improve the planting, use and maintenance of landscape plants. 4. The species number of school trees and flowers of 102 schools in Weonju and Hoengseong were 17species, 16species respectively. The major species of school trees in Weonju were Juniperus chinensis(24%), Ginkgo biloba(17%), Pinus densiflora(14%), Zelkova serrata(14%), and Pinus koraiensis(9%), and those of school trees in Hoengseong were Pinus koraiensis(44%), Abies holophylla(25%), Juniperus chinensis(8%), and Ginkgo biloba(8%). The major species of school flowers in Weonju were Rosa centifolia(47%), Forsythia koreana(24%), Magnolia kobus(12%), and Rhododendron schlippenbachii(6%), and those of school flowers in Hoengseong were Forsythia koreana(36%), Rhododendron schlippenbachii(33%), Magnolia kobus(6%) and Dicentra spectabilis(6%). 5. The species number of the protection trees designated by Woenju and Hoengseong were 15 species. The major species of protection trees were Zelkova serrata(100 trees), Ginkgo biloba(18) Pinus densiflora(7), Quercus spp. (5), Juniperus chinensis(4) and Alnus japonica(4). 6. The landscape plants planted around 2004 in weonju were Prunus yedoensis(2,563 trees), Betula platyphylla var. japonica(2,000), Abies holophylla(1,785), Diospyros kaki(1,100), Prunus sargentii(880) and Prunus armeniaca var. ansu(708) etc.. The shrubs planted were Rhododendron obutusum(21,559 plants), Rosa centifolia (7,150), Rhododendron yedoense var. poukhanense(5,950), Forsythia koreana(3,000) and Ligustrum obtusi[olium(2,500) etc.. The landscape plants planted in Hoengseong Acer triflorum(928trees), Prunus yedoensis(455), Zelkova serrata(327), Thuja orientalis(261), Prunus sargentii(257), Pinus koraiensis(200), Prunus persica for. rubro-plena(200) and Pyrus pyrifolia (200) etc.. The shrubs planted were Rhododendron yedoense var. poukhanense(15,936), Syringa dilatata(10,090), Forsythia koreana(9,660), Cercis chinensis(3,200), Buxus microphylla var. koreana(2,600) and Rosa centifolia(1,868) etc.. 7. The species numbers of the herbaceous plants planted in 2004 in Weonju were 24 species and the ratio of native species versus exotic were 7:17. The major species of perennial plants were Aster koraiensis(30,656 plants), Coreopsis drummondii(7,656), Rudbeckia bicolor(6,000), Chrysanthemum morifolium(4,850) and Chrysanthemum zawadskii var. latilobum(4,312). The major species of annuals and biennials were Cosmos bipinnatus(672,000 plants), Zinnia elegans(35,600), Petunia hybrida(26,920), Viola tricolor(23,000), Helianthus annuus(17,000), and Geranium cinereum var. pubcaulescens(5,200). In Hoengseong, the numbers of herbaceous plants were 906,310 plants and the species numbers were 15 species. The major species of perennials plants were Aster koraiensis(70,480 plants), Hemerocallis fulva(20,070), and Phlox drummondii(18,000). The major species of annuals and biennials were Phlox hybrida(174,000 plants), Cosmos bipinnatus(125,000), Zinnia elegans(109,000), Tagetes patula(96,700), Vinca rosea(89,000) and Calendula officinalis(70,000). 8. Through these result, it was thought that the diversification of planting species, the selection of plants suitable to each space and the generalization of use of native species were needed.