• Title/Summary/Keyword: Vegetation history

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Response of Old-field Plant Community to an Experimental Nitrogen Gradient (질소 시비 구배에 따른 묵밭의 식물 군집 반응)

  • Lee, Kyu-Song;Joon-Ho Kim
    • The Korean Journal of Ecology
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    • v.19 no.4
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    • pp.341-351
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    • 1996
  • In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

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A Study on the Evaluation of Biotope Value of Rural Areas in terms of Nature Experience and Recreation - A Case Study of Large Residential Land Development District - (자연체험 및 휴양적 관점에서 농촌지역의 비오톱 가치평가 연구 - 대규모 택지개발 사업지를 대상으로 -)

  • Cho, Hyun-Ju;Han, Sang-Yoel;Lee, Hyun-Taek;SaGong, Jung-Hee
    • Journal of Korean Society of Rural Planning
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    • v.16 no.3
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    • pp.87-101
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    • 2010
  • This research has a significance on providing basic material of landscape ecological planning and open space planning of the future site by selecting Sinseo innovative city area, large residential land development district in rural area, by classifying biotope types and implementing recreational value assessment in the level of area. First of all, as a result of classification of biotope types in research site, total 11 biotope type groups including stream biotope and its subordinate 51 biotope types. Also, as a result of the first value assessment of classified biotopes, there are total 5 types such as vegetation-full natural river, fallow ground in I grade. In addition, it is analyzed that grade II have 18 types, III are 10, IV are 12, the least valuable V are 6. Especially, grassland biotope(GD) was classified into grade II, which is one grade raised, because it is analyzed that it has high value in terms of normal access and availability although it was assessed as grade ill in terms of natural experience quality. Lastly, as a result of the second assessment, special areas for natural experience and recreation(1a, 1b) are 15, areas for natural experience and recreation(2a, 2b, 2c) are 47. Especially, the 52th drawing mark space was grade II in the first assessment but its value grade was upgraded because of its high value in terms of use evidence, size of the area, accessibility with housing area, history and cultural character and so on.

Surgical Treatment of Native Valve Endocarditis (감염성 심내막염의 외과적 치료)

  • Kim, Ae-Jung;Kim, Min-Ho;Kim, Gong-Su
    • Journal of Chest Surgery
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    • v.28 no.9
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    • pp.822-828
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    • 1995
  • This paper reports 15 native valve endocarditis cases had surgical operation in the past 10 years at the department of Cardiovascular and Thoracic Surgery, Chonbuk National University Hospital. In this study, 10 cases out of 15 were in class I or II by the New York Heart Association functional classification. None of the cases had a history of taking addictive drugs. Five cases were congenital heart disease, three cases were rheumatic heart disease and two cases were degenerative heart disease. Thus 10 cases had the underlying disease. All cases had antibiotics treatment for 3 to 6 weeks before operation. In the culture test, only four cases were positive in the blood culture and one case was positive in the excised valve culture. Organisms on blood and valve culture were Streptococcus epidermis, Streptococcus viridans, Staphylococcus aureus and Staphylococcus epidermidis. In the 10 cases without ventricular septal defect, the aortic valve was involved in four, mitral in four, both in two and involved valves in the 5 cases with ventricular septal defect were tricuspid in three, pulmonic in two. Eight cases had operation because they showed moderate congestive heart failure due to valvular insufficiency and vegetation with or without embolism. Seven cases had operation because they showed persistent or progressive congestive heart failure and/or uncontrolled infection. Five cases with ventricular septal defect underwent the closure of ventricular septal defect, vegetectomy and leaflet excision of the affected valves without valve replacement. In the cases without ventricular septal defect, the affected valves were replaced with St. Jude mechanical prosthesis. Postoperative complications were recurrent endocarditis in two, embolism in one, allergic vasculitis in two, spleen rupture in one and postpericardiotomy syndrome in one. At the first postoperative day, one case died of cerebral embolism. At the 11th postoperative month, one case died of recurrent endocarditis and paravalvular leakage in spite of a couple of aortic valve replacement. In the survived cases[13 cases in this study , all cases but one became class I or II by the New York Heart Association functional classification.

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The Holocene Environmental Change and Reconstruction of the Palaeogeography at Ilsan Area with the Special Reference to Pollen Analysis (花粉分析을 중심으로 본 一山지역의 홀로세 環境變化와 古地理復元)

  • Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.32 no.1
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    • pp.15-30
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    • 1997
  • This paper concerns the Holocene environmental change with vegetational history and sea-level fluctuation at Ilsan area by the analytical data of pollen, sedimentary facies and $C^14$-dating. The hypothetic palaeogeographic maps of the vegetation cover have been reconstructed with the reference to the periods of pollen zone. The environmental characteristics from the pollen zonation have been summerized as follows. 1)Pollenzone I(3.75~5.75m) showed the period of Alnus-and EMW-dominance. The study area was very humid under the influence of the transgression spreading widely from the rapid sea-level rise during the period(8,000~4,200y.BP). 2)Pollen zone II(5.75~6.35m) has been influenced by the fall of the sea-level and ground water surface. This zone(4,200~2,300y.BP) represented the period of spore~ and NAP-dominance with the increase of Pinus. 3) Pollen zone III(6.35~6.55m) has reflected the influence of the transgression and human interferences together. This zone(2,300~1,800y.BP) represented the period of NAP-dominance. The boundary between Subzone Ilb and Pollen zone III represents the same characteristics as what Weber says Grenzhorizont.

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A Study on Vegetation History of Organic Muds of Sorori Archaeological Site, Oksan-myeon, Cheongwon-gun, Korea (청원 옥산 소로리 유적지 일대 유기질 니층의 화분분석에 의한 식생변천사에 관한 연구)

  • 김주용;양동윤;봉필윤;이융조;박지훈
    • The Korean Journal of Quaternary Research
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    • v.15 no.2
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    • pp.75-81
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    • 2001
  • We have analyzed the pollen sequence since the Late Glacial at Sorori Archaeological Site. The Sorori Site is an open site located at Soro-ri, Oksan-myeon, Cheongwon-gun, Chungchongbukdo. The main results are as follows: Four forest zones have been distinguished. \circled1 OS-1 zone : Pinus-Abies-Picea forest (the sub-alpine conifer forest), the Late Glacial (about 15,000~10,000yr. B.P.) ; \circled2 OS-2 zone : Pinus-Colyus forest (the mixed conifer and deciduous broad-leaved forest), R I (about 10,000 yr.B.P.) : \circled3 OS-3 zone : Alnus-Quercus forest (the cool temperate deciduous broadleaved forest), R II(about 10,000~2,000yr.B.P.) : \circled4 OS-4 zone : Pinus forest (the conifer forest), R III (about after 2,000yr.B.P.)

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Homograft Replacement in Prosthetic Valve Endocarditis(PVE) -One Case Report (심내막염 환자의 동종이식편 치환술 -1례 보고-)

  • Park, Jung-Won;Park, Guk-Yang;Kim, Ung-Han
    • Journal of Chest Surgery
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    • v.30 no.8
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    • pp.815-818
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    • 1997
  • Prosthetic valve endocarditis(PVE), although uncommon, is associated with significant mortality if the infection spreads into the paravavular structures with later abscess formation. However, combined antibiotic and surgical treatment is often successful. Accurate diagnosis by on echocardiography, effective myocardial protection during operation and increased surgical experience have improved the short-term and long-term outcomes for patients with PVE. A 35-year-old male had a history of replacement of aortic and mitral valve, and tricuspid annuloplasty on August 1994, was admitted due to sudden onset of aphasia, leftward deviation of both eyeballs and spiking fever and diagnosed of having PVE by echocardiography. Reoperation was done after 6weeks of antibiotic treatment. On the operative field, we could notice circumferential vegetation along aortic valve annulus, paravalvular leakage and abscess pocket. The mitral valve amlulus was healthy. The patient underwent redo aortic valve replacement using cryopreserved aortic homograft after radical debridement of infected issue. During the follow up of 7 months period the homograft was well functioning without recurrence of symptoms.

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A Study on the Causes of Child Hearing Loss Under Age 5 in Korea (우리나라 유아난청의 원인에 관한 고찰)

  • 노관택;민양기;이희배;고건성
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1978.06a
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    • pp.8.2-8
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    • 1978
  • This paper was designed to investigate the causes of child hearing loss which is essential to language development especialy in young childhood. Accurate history taking, precise otolaryngological examination and impedence audiometry were performed on 185 hard of hearing children under age 5 during last 8 months and investigated its causes. The results were as follows: 1. Infections diseases were the most common causes of sensorineural hearing loss (44/123cases, 30.1%), and mother's condition during pregnancy the second, and birth injury or head trauma the third. 2. Acute or chronic ear ear diseases were the most common causes of counductive hearing loss (32/62, 51.6%), frequent URI the second (19/62, .30.6%), and adenoid vegetation the third (7/62, 11.3%). 3. The majority of causes of child hearing loss under age 5 was exogenous (179/185 cases, 96.8%), and the minority was endogenous (6/185 cases, 3.2%).

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A Case of Septic Pulmonary Embolism Associated with MRSA Infective Endocarditis (메치실린 내성 황색포도상구균 세균성 심내막염에 의한 패혈성 폐색전증 1예)

  • Lee, Ki-Jong;Kim, Nha-Young;Kim, Ja-Seon;Yun, Han-Kyeol;Oh, Mi-Jung;Kim, Do-Hoon;Cho, Sang-Kyun;Ryu, Han-Young;Bae, Young-A;Kim, Dae-Bong;Shin, Mi-Kyung;Chin, Jae-Yong
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.2
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    • pp.124-128
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    • 2010
  • Septic pulmonary embolism is the process in which an infected thrombus becomes detached from its site of origin and lodges in a pulmonary artery, and is usually associated with infective endocarditis, especially right-sided, or infection-associated with indwelling catheters, peripheral septic thrombophlebitis, and periodontal diseases, etc. Here, we report a case of septic pulmonary embolism associated with tricuspid valve infective endocarditis. A 23-year-old female was admitted to our hospital, due to fever, sore throat, and myalgia. In her past medical history, she had undergone a surgical operation for closure of a ventricular septal defect, but was informed that the operation resulted in an incomplete closure. The initial chest radiograph demonstrated multiple rounded, parenchymal nodules in various sizes; several nodules had central lucency suggesting cavitations. Echocardiography demonstrated a large vegetation attached to the septal tricuspid valve leaflet, extending from right ventricular inflow tract to outflow tract. Computed tomography of thorax revealed bilateral peripheral nodules and wedge-shaped consolidation at various sizes, mostly accompanied by cavitations.

Mid-term (2009-2019) demographic dynamics of young beech forest in Albongbunji Basin, Ulleungdo, South Korea

  • Cho, Yong-Chan;Sim, Hyung Seok;Jung, Songhie;Kim, Han-Gyeoul;Kim, Jun-Soo;Bae, Kwan-Ho
    • Journal of Ecology and Environment
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    • v.44 no.4
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    • pp.241-255
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    • 2020
  • Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

Installation and Vegetation Management for Enhanced Authenticity of Jeju Ohyundan (제주 오현단의 진정성 제고를 위한 시설 및 식생관리)

  • Rho, Jae-Hyun;Oh, Hyun-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.3
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    • pp.25-37
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    • 2013
  • The purpose of this study is to draw reasonable management plans to reinforce essence of Ohyundan(五賢壇: Five sprit tablets), a sacred site and monument of Jeju, by investigating and analyzing current status and problems of cultural landscape elements(e.g. architectural structures, installation, letters carved on the rocks, actual vegetation, etc.) while grasping placeness contained in Ohyundan through consideration of its history and transition process of Ohyundan a future being and shrine of Gyulrim Seowon(橘林書院) in Jeju. Results derived from research are summarized as follows. Ohyundan is noted due to its placeness in that it was a place for Gyulrim Seowon, Jeju's one and only Saaek Seowon(賜額書 院) and it was a symbolic space of exile culture in Jeju. As it is inferred from Gyulrim Seowon, which is dangho(堂號: clan name) of Seowon, orchards surrounding all over places are a signature landscape element that shows placeness of the past Ohyundan. Joduseok(俎豆石: altar stone), representing a core installation of Ohyundan and ancestral tablet of five spirits, created a refined place by putting up common stones around altar and founding blocked stones to wall. This refinement and thrift served basic mind of Neo-Confucianism, and led to of Jeju's Jonyang mind(spend-thrift mind). In conclusion, a practice plan is a prerequisite to restore essence of Ohyundan by actively excluding installations not suitable for placeness or overly designed such as Jeju Hyangrodang(a center for the elderly) and numerous monument houses. On the other hand, together with Joduseok, as letters carved on the rocks such as 'Jeungjoo Byukrip(曾朱壁立)' and 'Gwangpoongdae(光風臺)' and Yoocheonseok serve as a signature landscape that well shows mind of five spirits and teaching of Neo-Confucianism, and also a trace from a confucian viewpoint deeply rooted in Jeju, they are judged as a cultural landscape corresponding to the essence of place in Ohyundan which requires proactive preservation and plans for public relations. Together with this, although many different old big trees such as Pinus densiflora , Pinus thunbergii, Quercus variabilis, Celtis sinenis, Zelkova serrata and Rhus succedanea are a landscape element that increases sacred Ohyundan and commemorative value, now required is thorough entity tree management by assigning serial number on them as many of them were dead or removed resulting from transition process of land use. Further, to reinforce quality of site location belonging to Gyulrim Seowon, a prerequsite is to review plans that create Gyulrim at reinstalled site of building and raw land.