• Title/Summary/Keyword: disturbance ecology

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Test of Intermediate Disturbance Hypothesis by Experimental disturbance Gradient in Old-Field Plant Community (묵밭에서 교란처리구배에 따른 중간교란가설의 검증)

  • 이규송;김준호
    • The Korean Journal of Ecology
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    • v.21 no.3
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    • pp.233-241
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    • 1998
  • In order to test of intermediate disturbance hypothesis that an intermediate level of disturbance maximize biodiversity and to elucidate the effect of disturbance during the early old-field succession, the response of plant community along an experimental disturbance gradient was investigated in a five-year old-field. Response of plant community along an experimental disturbance gradient was connected with light condition because artificial disturbance gradient had been treat by clipping of plants and removing of litter. Artificial disturbance in five-year old-field plant community retarded rate of succession by increasing invasion and performance of the earlier successional species in the initial and middle stage of disturbance treatment. The species richness in the blocks of intermediate disturbance level showed the peak in early and mid-summer. This result did correspond with the prediction of intermediate disturbance hypothesis.

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Study on Environmental Risk Assessment for Potential Effect of Genetically Modified Nicotiana benthamiana Expressing ZGMMV Coat Protein Gene

  • Kim, Tae-Sung;Yu, Min-Su;Koh, Kong-Suk;Oh, Kyoung-Hee;Ahn, Hong-Il;Ryu, Ki-Hyun
    • The Plant Pathology Journal
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    • v.22 no.4
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    • pp.353-359
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    • 2006
  • Transgenic Nicotiana benthamiana plants harboring the coat protein(CP) gene of Zucchini green mottle mosaic virus(ZGMMV) were chosen as a model host for the environmental risk assessment of genetically modified plants with virus resistance. This study was focused on whether new virus type may arise during serial inoculation of one point CP mutant of ZGMMV on the transgenic plants. In vitro transcripts derived from the non-functional CP mutant were inoculated onto the virus-tolerant and -susceptible transgenic N. benthamiana plants. Any notable viral symptoms that could arise on the inoculated transgenic host plants were not detected, even though the inoculation experiment was repeated a total of ten times. This result suggests that potential risk associated with the CP-expressiing transgenic plants may not be significant. However, cautions must be taken as it does not guarantee environmental safety of these CP-mediated virus-resistant plants, considering the limited number of the transgenic plants tested in this study. Further study at a larger scale is needed to evaluate the environmental risk that might be associated with the CP-mediated virus resistant plant.

Ecological resilience of soil oribatid mite communities after the fire disturbance

  • Kim, Ji Won;Jung, Chuleui
    • Journal of Ecology and Environment
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    • v.36 no.2
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    • pp.117-123
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    • 2013
  • This study investigated the impact of the fire disturbance and the pattern of recovery of soil dwelling oribatid mite communities with respect to the resilience from the fire disturbance. Oribatid mites are important decomposer animals of plant debris in soil with the feeding habits of saprophagy and mycophagy. Massive wild fire reduced soil oribatid mite abundance and diversity. The impact varied relative to the intensity of the disturbance. The proportion of the species common to the non-disturbed natural site increased as the time after the disturbance elapsed, which implying some degree of naturalness occurring in reorganization phase of the oribatid mite community. From the sites with different degree of fire impact, we found higher diversity in intermediately disturbed sites than in severely disturbed or non-disturbed site, supporting the intermediate disturbance hypothesis. Also this study showed that with differential degree of disturbance plots, resilience pattern after the disturbance can be explored even with shorter period research relative to the ecological succession of community.

Recolonization of benthic macroinvertebrates after anthropogenic disturbance in natural streams, South Korea

  • Chun, Seung-Phil;Chon, Seung-Hoon;Lee, Seung-Oh;Im, Jang-Hyuk;Lee, Woo-Kyun;Kim, Myoung-Chul
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.228-235
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    • 2015
  • Stream ecosystems are closely related to many human activities. Therefore, streams are affected by anthropogenic disturbances such as riverine development and gravel-mining as well as deterioration of water quality. The goal of this study was to elucidate the recolonization process of the macroinvertebrate community after a small-scale anthropogenic disturbance. Field studies were conducted at three sites in a natural stream. The number of recolonizing species tended to increase slightly over time, exceeding the total species number of the control. Ephemeroptera contributed the most to shaping the recolonizing pattern of the entire community. From the result of changes in dominant species, the early recolonizers of each site were the species that showed more frequent occurrence particulary at each sites. But the late recolonizers are Chironomidae at all the sites commonly. This result implies that the actual differences exist among the recolonizing trends of each benthic macroinvertebrate taxon. Collector-gatherers and scrapers comprised about 70% of the recolonizing species. These results indicate that the recolonizing process of an aquatic community after an artificial disturbance depends on the environmental conditions(particularly substratum composition or organic pollution) of the habitat.

Composition and Structure of Himalayan Oak (Quercus leucotrichophora A. Camus) Forest under Various Degrees of Disturbance

  • Prasad, Sunil;Uniyal, Pooja;Chauhan, D.S.
    • Journal of Forest and Environmental Science
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    • v.31 no.1
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    • pp.7-13
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    • 2015
  • Forest disturbance sometime considered as a tool of management as it believed that mid level disturbance constructs better micro-climatic conditions which ultimately boost up the plant diversity. The effect of different levels of disturbance on species composition and regeneration is very important. Present attempt was carried out in a temperate evergreen oak forest which was under various degree of disturbance. The study area is one of the large ranges of oak forest in Garhwal Himalaya and compensating various types of daily needs of local people. On the basis of IVI values Quercus leucotrichophora holds first position in all the disturbance zones whereas Myrica esculenta upgraded it's rank in highly disturbed zone and showed less impacted species by disturbance. Berberis aristata and Eupatorium adenophorum in shrub layer and Anaphalis adnata and Bidens pilosa in herb layer were found as disturbance friendly species because they attained higher rank in highly disturbed zone whereas Caryopteris foetida was found disturbance-sensitive in shrub layer. The banj oak regenerated well under mid disturbance as compared to no and high degree of disturbance and a sharp downfall in the species diversity was recorded with increasing magnitude of disturbance. Density-diameter curves showed a reverse trend of lower density in higher girth classes. The results of the study should be useful for the forest management strategies.

A Correlation Analysis between Physical Disturbance and Fish Habitat Suitability before and after Channel Structure Rehabilitation (하천구조 개선에 따른 어류 서식적합도와 물리적 교란의 상관분석)

  • Choi, Heung Sik;Lee, Woong Hee
    • Ecology and Resilient Infrastructure
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    • v.2 no.1
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    • pp.33-41
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    • 2015
  • In this study, an optimal improvement method of stream channel structure is presented for the enhancement of fish habitat suitability by genetic algorithm. The correlation between fish habitat suitability and physical disturbance in stream is analyzed according to the changes of hydraulic characteristics by channel structure rehabilitation. Zacco koreanus which is an indicator fish of the soundness of aquatic ecosystem was selected as a restoration target species by investigating the community characteristics of fish fauna and river environments in Wonju stream. The habitat suitability is investigated by PHABSIM with the habitat suitability index of Zacco koreanus. Hydraulic analysis by HEC-RAS and physical disturbance evaluation in stream are carried out. The optimal channel width modified for the enhancement of fish habitat suitability is provided. The correlation analysis between habitat suitability and physical disturbance with the change of hydraulic characteristics by channel modification showed that the proper channel modification enhanced fish habitat suitability and mitigated physical disturbance in the stream. The improvement of physical disturbance score by the channel structure rehabilitation for the enhancement of fish habitat suitability was confirmed in this study.

The change of core habitats of the cranes due to release of the civilian control zone; CCZ and construction disturbance (서식지 교란 및 민간인통제지역 해제에 의한 두루미와 재두루미의 핵심서식지 변화)

  • Yoo, Seunghwa;Jung, Hwayoung;Kim, Kyoungsoon;Yu, Dong Su;Kim, Namshin;Kim, Hwajung;Hur, Weehaeng;Kim, Jinhan;Lee, Kisup
    • Journal of Environmental Impact Assessment
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    • v.24 no.4
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    • pp.301-316
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    • 2015
  • The endangered species, The Red-crowned Crane and the White-naped Crane are vulnerable species to the disturbance for human beings. We examined the importance of CCZ for the cranes by comparing the crane's density in some CCZ-released areas, which are cranes' wintering site in Cheorwon. We also assessed influence of disturbance such as construction and greenhouses on core habitats of cranes. Our study results suggested that the construction and reclamation in the CCZ shrunk core habitat area while increasing core area of far from the construction and reclamation area. The CCZ has been set since March, 2011 and the number of greenhouse has rapidly increased after 2012. As the number and size of greenhouse in the area where designation of CCZ was cancelled increased, foraging area of cranes diminished. Although the area where designation of CCZ was cancelled seemed to have more human disturbance than CCZ, the foraging density of cranes did not decline and even that of white-naped cranes increased. This could be the influence of artificial food supply at their roosting site. In conclusion, if the area of CCZ decline continuously in the future, density of cranes would decrease.

Development and Roles of Landscape Ecology as An Emerging Opportunity for Ecology (생태학의 새로운 분야로서 경관생태학의 발전과 역할)

  • 홍선기;이창석
    • The Korean Journal of Ecology
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    • v.20 no.3
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    • pp.217-227
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    • 1997
  • Landscape ecology is an emerging interdisciplinary ecology field to understand the holistic human and natural systems on the basis of concept and database obtained from pure ecology. Landscape ecology is an integrated ecology widely available for environmental science such as nature conservation and sustainable land-use planning. It is also a practical study as an applied ecology to restore and to manage local environment. Landscape ecological study is realized by embodiment of human disturbance system which is rigorously extending on natural system. Considering Korean status without landscape ecological studies, we briefly reviewed establishing process, study goal and methodology of landscape ecology as well as the related several concepts through current landscape ecological studies in the world. We hope that this paper will be helpful to ecologists having interest in landscape ecology.

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Responses of Shorebirds to Disturbance at Roosting Sites

  • Kim, Hwa-Chung;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • v.30 no.1
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    • pp.69-73
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    • 2007
  • The sources and the frequency of disturbances and the responses of shorebirds to disturbances were studied at four roosting sites on Ganghwa Island and Yeongjong Island. The mean frequency of disturbance to roosting shorebirds was 2.7 per hour. Human activities contributed to the disturbance in 65% of all cases. Disturbance frequencies in saltpans were higher than those in the upper tidal zone, fishponds and salt marshes. Response patterns of shorebirds to disturbances were associated with the source of the disturbance. Disturbance caused shorebirds to change their behavior and to reduce roosting time at their roosting sites. Four patterns of responses by roosting shorebirds to disturbance were found, including: (1) leaving the roosts, (2) changing their location within the site, (3) leaving and returning, and (4) remaining in place. In the latter three response patterns, the birds tended to remain in their initial roosting sites, in contrast with the leaving pattern, which involved departing from the roosting area. Factors affecting these response patterns were time from high tide and time of day. When the time from high tide was greater, and the time of day was later, more birds stayed at the roost. The absence of sufficient alternative roosts in the study areas forced the birds to choose between tolerating the current disturbance, or moving to distant roosts.