• Title/Summary/Keyword: Introduced species

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Flora and Distribution of Mt. nam Park, Seoul (서울 남산공원의 식물상과 그 분포)

  • 길봉섭;유현경;김병삼;김현철;전의식;김영식;김창환;윤경원
    • 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.

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Cold Tolerance of Native and Introduced Evergreen Rhododendron Species According to Morphological and Physiological Changes (국내 자생종 및 도입종 만병초의 내한성과 관련된 형태 및 생리적변화)

  • Lee, Byung-Chul;Kim, Seong-Min;Cheng, Hyo-Cheng;Shim, Ie-Sung
    • Horticultural Science & Technology
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    • v.29 no.6
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    • pp.561-567
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    • 2011
  • Cold tolerance of the native Rhododendron species which are on the verge of extinction in Korean nature were compared with the introduced species and its mechanism were studied physiologically with the investigation of the leaf angle, leaf curling, and photosynthetic activity. The degree of cold tolerance measured with the leaf burning after winter season was higher in the native species, Rhododendron brachycarpum and Rhododendron brachycarpum var. roseum than all the introduced species. 'Nova Zembla', an introduced species, showed high sensitivity to the low temperature. Changes in leaf angle by the low temperature were bigger in 2 native species and 'Parker's Pink' than the other introduced species and small comparatively in 'Nova Zembla' and 'Cunningham's White' cultivar. Leaf curling also occurred strongly in 2 native species by the low temperature. While, it was comparatively little and mild in the other introduced species. Therefore these results suggested that the leaf movement such as leaf angle change and curling adapted to the low temperature is positively related to the cold tolerance of 2 native species. By the way, such relationship is not explainable in the cold-sensitive 'Parker's Pink' cultivar showing comparatively stronger leaf movement. Photosynthetic activity measured before the winter season was high in the cold-tolerant R. brachycarpum and its recovery after winter season was faster in the 2 native species and the introduced 'Cynosure' cultivar than the other introduced species. They were the lowest in the most cold-sensitive 'Nova Zembla'. This phenomena occurred similarly even in the stomatal conductivity, suggesting that the movement of water from the roots to the leaves is better and then the leaf burning after winter season become small in the cold-tolerant species. The recovery of photosynthetic activity and stomatal conductivity was comparatively slower in the cold-sensitive 'Parker's Pink'. From the above results, leaf behavior adapted to the low temperature during the winter season and water movement to the leaves are related collectively to the cold tolerance represented as the leaf burning in the Rhododendron species is suggested.

A Study on Changing of Flora between Pre and Post of Restoration in Cheonggyechon Stream (청계천 복원 전·후의 식물상 변화 연구)

  • Kang, Soo Hak;Kim, Hyeong Guk;Koo, Bon Hak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.3
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    • pp.8-13
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    • 2007
  • This study was surveyed to know changing flora between pre and post of restoration in cheonggyechon. As results, it was surveyed families 33, species 94 in 2003 and families 39, species 156 in 2005. In 2006, it was surveyed families 38, species 171. This result shows that cheonggyechon is unstable initial condition in restored stream ecosystem. Also, Naturalized species was 19 species in 2003 and it was respectively 44, 46 species in 2005, 2006. Hazard species of ecosystem was in common 3 species in three surveys. Recently, as time goes by, introduced species are increasing. And succession has mainly been progressed by one year or binary herbs. To administer restored stream ecosystem, monitoring is essential. Therefore, continuous monitoring about Naturalized species and Hazard species of ecosystem is also very important. Further, Because change of vegetation on pre and post of Restoration in Cheonggyechon Stream is very important, Monitoring will have been surveyed continuously.

Floral Changes During Three Years after the Establishment of the Youido Ecology Park (여의도 샛강 생태공원의 조성 후 3년간의 식물상 변화)

  • 전승훈;차윤정;최정권
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.5
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    • pp.76-86
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    • 2000
  • The purpose of this study is to fiure out the floral changes during three years after construction of the Youido Ecology Park. Yearly change of plant species composition, distributed at the research field, had been investigated for three years since 1996. To compare and investigate the changes of the establishment of the Ecology Park, we have analyzed the distribution characteristics of plant species, exotic naturalized species, and so on. The results obtained through this investigation are as follows; 1) Total numbers of plant species were 106, 170, 175, and 148, in the year of 1996, 1998 1999, and 2000, respectively. While the most of cultivated species before th establishment were decreased, the naturalized species such Phargmites communis Trin, and Artemisia selengensis Turcz. etc, were increased. 2) Forty three species of exotic naturalized species were investigated and were increased at the early stage of the establishment, but showed decreasing trend recently. 3) Sixty five species of introduced and planted species were investigated. Most of them were occurred at the first year after the establishment, but since 1999, there has been a significant decrease. 4) Sixty seven species among total 235 were verified as the wetland-adapted plants. The ratio to the total numbers were low, but the occupied area of a few species was expanded. Therefore, it indicates that monitoring on the physical environments of the Youido Ecology Park was urgently required.

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Secondary human impacts on the forest understory of Ulleung Island, South Korea, a temperate island

  • Andersen, Desiree
    • Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.202-211
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    • 2019
  • Oceanic islands are biologically important for their unique assemblages of species and high levels of endemism and are sensitive to environmental change because of their isolation and small species source pools. Habitat destruction caused by human landscape development is generally accepted as the main cause of extinction on islands, with exotic species invasion a secondary cause of extinction, especially on tropical islands. However, secondary impacts of human development (e.g., general degradation through resource use and exotic species introduction) are understudied on temperate islands. To determine secondary impacts of human development on the understory vegetation community, 90 field sites on Ulleung Island, South Korea, were sampled during the summer of 2016. Understory vegetation was chosen as it is a proxy for ecosystem health. Diversity and percent cover of introduced, native, and endemic species were tested against proximity to developed areas and trail usage using a model selection approach. Diversity was also tested against percent cover of three naturalized species commonly found in survey plots. The main finding was that distance to development, distance to town, and trail usage have limited negative impacts on the understory vegetation community within best-supported models predicting native and introduced cover and diversity. However, endemic species cover was significantly lower on high usage trails. While there are no apparent locally invasive plant species on the island at the time of this study, percent cover of Robinia pseudoacacia, a naturalized tree species, negatively correlated with plot diversity. These findings indicate that forests on Ulleung Island are not experiencing a noticeable invasion of understory vegetation, and conservation efforts can be best spent preventing future invasions.

Early Immigration Characteristics of Benthic Macroinvertebrates after the Restoration of Mountain Wetlands

  • I-Chan Shin;Sang-Woo Jung;Haeng-Seop Song;Jin-Soo Byun;Jung-Ho Park
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.3
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    • pp.95-103
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    • 2023
  • This study aimed to identify the initial migratory macroinvertebrate species in two newly created mountain wetlands. To analyze the initial immigration species of macroinvertebrates, two experimental sites and two control sites were selected after habitat creation and investigated thrice from spring to fall. Benthic macroinvertebrates were collected quantitatively from each site using a Surber sampler and Modified D-frame deep net. After restoration at the two experimental sites, the number of macroinvertebrate species and individuals gradually increased from spring to fall and continued to increase over time with the development of waterside vegetation and habitat stabilization at the experimental sites. The species initially introduced to mountain wetlands after their creation were Ephemera strigata, Ephemera orientalis, Chironomidae sp., and Aquaris paludum. Subsequently, predators such as Davidius lunatus, Sieboldius albardae, Oyamia nigribasis, and Sialis longidens were introduced. Additionally, as a differentiating physicochemical factor between the two habitats, current velocity, which determines the distribution characteristics of benthic macroinvertebrates, and water temperature, which impacts the growth of organisms, showed a relatively stronger influence.

Fluctuation of Introduced Fish and Characteristics of the Fish Community in Lake Soyang (소양호의 도입어종 변동과 어류 군집 특성)

  • Byeon, Hwa-Keun
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.401-409
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    • 2015
  • The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.

A Study on the Utilization of Interior Lanscape Plant through the Investigation of Image -Focused on the Tall Trees- (이미지 조사를 통한 자생수종 활용에 관한 연구 -상층목을 중심으로-)

  • 조현진;방광자;이남현;이영현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.3
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    • pp.210-221
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    • 1997
  • This study was conducted to investigte the visual preference and response between introduced and native trees for utilization of the south native trees in interior space. 1. The intensity of illumination was below 500lux at 24 buildings of interior spaces surveyed. Generally the temperature was 24~$26^{\circ}C$, and humidity was 60~70%. 2. Total number of introduced tree species were 9 familiar, 16 genus, 18 species, especially palm genus were the largest tree among them at these surveyed interior spaces, but native trees were only 2 species. The introduced tree of 2 to 3m in height was 46 percent, and the case of 1.2 to 2m was 42 percent. 3. The mean of visual preference was the highest at Rhapis excelsa and howeia belmoreana, and followed with Neolitsea sericea, Daphniphllum macropodum, Listsea japonicum. In the mean of visual preference for selected tree groups, native tree was not different as compared with introduced tree. 4. Visual image factor of the native and introduced trees at interior spaces was classified by individual factor and emotional factor. These 2 factors were shown 66.5% total variance. The native tree was strongly recognized on individual factor, as , and introduced tree was also strongly recognized on emotional factor. 5. In the analysis of visual preference and image, a difference between the selected groups of the introduced and native trees were not shown significant, and the introduced trees were similar to the native trees on the visual image. This result was as follow There was an analogy between Cinnamomum camphora, Ligustrum japonicum and Ficus retusa, Ficus benjamina. There is an analogy between Castanopsis cuspidata var. sieboldii, Cinnamomum japonicum and Ficus retusa, Ficus benjamina. There was an analogy between Elaeocarpus sylvestris var. ellipticus, Fatsia japonica and Rhapis excelsa, Howeia belmoreana. There was an analogy between Neolitsea sericea, Daphniphyllum macropo여, Listsea japonica and Rhapis excelsa, Howeia belmoreana. There was an analogy between Elaeocarpus sylvestris var. ellipticus, Fatsia japonica and Dracaena fragranse, Ficus elastica, Monstera deliciosa.

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Phytophthora Species, New Threats to the Plant Health in Korea

  • Hyun, Ik-Hwa;Choi, Woobong
    • The Plant Pathology Journal
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    • v.30 no.4
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    • pp.331-342
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    • 2014
  • Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

A New Marine Species of Miracula (Oomycota) Parasitic to Minidiscus sp. in Iceland

  • Buaya, Anthony T.;Scholz, Bettina;Thines, Marco
    • Mycobiology
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    • v.49 no.4
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    • pp.355-362
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    • 2021
  • Obligate endoparasitic oomycetes are known to ubiquitously occur in marine and freshwater diatoms, but their diversity is still largely unexplored. Many of these parasitoids are members of the early-diverging oomycete lineages (Miracula, Diatomophthora), others are within the Leptomitales of the Saprolegniomycetes (Ectrogella, Lagenisma) and some have been described in the Peronosporomycetes (Aphanomycopsis, Lagenidium). Even though some species have been recently described and two new genera were introduced (Miracula and Diatomophthora), the phylogeny and taxonomy of most of these organisms remain unresolved. This is contrasted by the high number of sequences from unclassified species, as recently revealed from environmental sequencing, suggesting the presence of several undiscovered species. In this study, a new species of Miracula is reported from a marine centric diatom (Minidiscus sp.) isolated from Skagaströnd harbor in Northwest Iceland. The morphology and life cycle traits of this novel oomycete parasite are described herein, and its taxonomic placement within the genus Miracula is confirmed by molecular phylogeny. As it cannot be assigned to any previously described species, it is introduced as Miracula islandica in this study. The genus Miracula thus contains three described holocarpic species (M. helgolandica, M. islandica, M. moenusica) to which likely additional species will need to be added in the future, considering the presence of several lineages known only from environmental sequencing that clustered within the Miracula clade.