• Title/Summary/Keyword: 식생조도

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Summer Algal Communities in the Rocky Shore of South Sea of Korea -II. Subtidal communities- (남해의 하계 해조군집 -II. 조하대의 군집-)

  • KANG Rae-Seon;JE Jong-Geel;SOHN Chul-Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.2
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    • pp.182-197
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    • 1993
  • Algal community on the subtidal rocky zone of the South Sea of Korea was divided into two or three sequencing zones. The upper subtidal zone was characterized by the wave exposure-tolerant surf wrack(Pachymeniopsis, Gigartina), which formed dense swirling carpet. Its vertical range was from the surface to $3{\sim}5$ meters in depth, and more deeply extended in turbid waters including Sorido, Yokchido, Pijindo, Manjedo. The mid subtidal zone ranging from 5 to 25 meters in depth was characterized by a large brown algal forest (Ecklenia, Sargassum). But it was generally unrecognizable in that turbid waters, in which the vertical limit of vegetation was at most $10{\sim}15$ meters in depth. The low subtidal zone was characterized by a general lack of algal species and was not easily distinguished from the mid or sometimes from the upper zone. There was a distinct difference in abundance of vegetation between turbid waters and clear waters including Munsom, Kwantaldo, Yosodo, Hongdo, Ch'ujado. In turbid waters the vegetation was much poorer because the tubidity caused from the muddy sediment inhibited an algae to settle down and to grow up. On the basis of the phytogeographical methods using UPGMA, the 10 studied islands were classified into two groups, Munsom and the others. This floristic discontinuity between the two groups might be caused from the difference of water temperature.

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Salty Wind Damages in Windbreak Forests of Jeju Island by Typhoon Bolaven (태풍 볼라벤에 의한 제주도 방풍림 조풍(潮風) 피해)

  • Choi, Kwang Hee;Choi, Gwangyong;Kim, Yoonmi
    • Journal of the Korean Geographical Society
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    • v.49 no.1
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    • pp.18-31
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    • 2014
  • In this study, the spatio-temporal patterns of salty wind by typhoon in Jeju Island and their damages to windbreak forests are examined. To investigate these patterns, field trips as well as analyses of meteorological data were conducted after the attack of typhoon BOLAVEN in late August, 2012. Collected data show that salty wind damage in windbreak trees by the typhoon was distinct in the southern and eastern coastal areas due to the southeasterly gusts with less precipitation. Most of trees including Japanese cedar (Cryptomeria japonica) within 8km from the coast as well as pine trees (Pinus thunbergii) along the coasts were damaged by salty water driven by the typhoon, but the magnitude of its damages and recovery rates of damaged vegetation varied by species. These results indicate that prediction and proactive activities for salty wind are needed to reduce its damages to local vegetation particularly before the arrival of a dry typhoon accompanying gusty wind.

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Patterns of Utilizing Sole Carbon Source by Soil Microbes in a Forest Soil (토양 세균 군집의 유일탄소원 이용에 의한 지문분석)

  • 송인근;최영길;안영범;신규철;조홍범
    • Korean Journal of Microbiology
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    • v.35 no.1
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    • pp.65-71
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    • 1999
  • This study was carried out utilzing ability of sole carbon sources in soil microbial communities used by Biolog GN microplate. Cluster analysis showed that soil microbial cornmuties were categorized into three groups as forest, non-forest soil and naked soil of microbial group. Soil microbial commutites in a forest soil of Qirercus mongoIica was divided into another group microbial communites in Qirercus dendata vegetation soil and Pinus dnzsqlora vegetation soil by Multidimensional scaling(MDS). Generally, sole carbon utilzing abilties were higher in order of polymer, amino acids and carboxylic acids, but it was lower in amides substrates carbon group. From the result: it was supposed that metabolic diversity of microbial communities was corresponded to vegetation succession.

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Analysis of river flow characteristics for vegetation in real-scale experiment center (실규모 실험장에서의 식생에 따른 하천 흐름특성분석)

  • Kim, Jong Min;Kim, Hyung Suk;Lee, Chan Joo;Kim, Sung Joong;Kim, Dong gu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.271-271
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    • 2019
  • 하천에서의 식생은 하천의 조도 및 흐름특성을 변화시키는 요인 중 하나로서 하천 내의 식생밀도 변화로 인하여 발생한 하상변동은 장기적으로 하천내의 하중도가 발생하거나, 식생으로 인해한 방향으로 편중된 흐름으로 인하여 제내지 방향으로의 하천 침식이 발생하고, 이에 따라 구조물의 안정성에 영향을 미치는 등 하천의 중 장기 계획 시 고려해야할 중요한 요인이다. 이에 따라 식생 모형을 이용한 다양한 흐름특성 분석 실험들이 수행되었으나, 대부분의 연구에서는 식생을 단순화하여 모형으로 사용하였기 때문에 실제 식생에 대한 영향성을 보기에는 한계가 존재한다. 건설기술연구원의 하천실증연구센터에서는 이러한 식생의 영향을 분석하기 위하여 네덜란드의 Deltares, 핀란드의 Aalto 대학 등과 함께 다년간 국제공동연구를 수행하였으며, 금번 소개하는 실험에서는 식생밀도에 따른 흐름변화, 하상변동 및 환경 변화 등의 검토를 목적으로 하였다. 실험은 총 2가지 유량 조건에 대하여 수행되었으며, 실험 중 흐름의 안정화를 확인하기 위하여, 유출수조에는 6개의 압력식 수위계를 설치하여 실험기간동안 유출수조에서의 수심변화를 측정하였고, 하도에는 실험구간 상 하류에 SonTek의 SL-1500 및 SL-3000을 이용하여 지속적으로 수심을 측정하고, 이 외에도 하류단에 2개의 압력식 수위 측정장비를 설치하여 수심을 모니터링하였다. 실험에 사용된 식생은 높이 약 1.5m의 2가지 밀도로 폭 2m, 길이 4m의 규모로 설치하였고, 광파기와 3차원 레이저 스캐너를 이용하여 실험 전 후의 식생 주변 및 전 실험구간의 하상을 측량하였다. 흐름특성 분석을 위한 수리 측정은 Nortek사의 Vectrino를 이용하여 측정하였고, 총 24개 측선에 대하여 각 측선별 5 ~ 10개의 유속자료를 측정하였으며, 각 측점별로 90초간 자료를 수집하였다. 흐름특성 분석에 사용된 유속자료는 이상치를 제거한 후 수행되었으며, 이상치의 제거는 표준편차의 3배 이상의 편차를 갖거나, 측정자료의 자기상관도가 70% 이하인 값들은 제거한 후 분석을 수행하였다. 흐름 분석을 위한 측정자료를 이 외에도 캠코더를 이용한 표면유속영상 측정기법과 ADCP를 이용한 측정도 병행하였으나, 본 연구에서는 Vectrino로 측정된 결과만을 소개하고자 한다.

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Development of Vegetation Indicator for Assessment of Naturalness in Stream Environment (하천환경의 자연성 평가를 위한 식생지표의 개발)

  • Chun, Seung-Hoon;Chae, Soo-Kwon
    • Journal of Environmental Impact Assessment
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    • v.25 no.6
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    • pp.384-401
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    • 2016
  • The vegetation assessment indicator has been developed recently as a biological part of the integrated assessment system for river environment to improve the efficiency of river restoration projects. This study carried out to test the vegetation assessment indicator and to reset its grade criteria on experimental streams. We classified and mapped vegetation communities at the level of physiognomic-floristic composition by each assessment unit. A total of 204 sampling quadrats were set up on the 68 assessment units at 5 experimental streams. By analyzing the vegetation data collected, we examined the appropriate numbers of sampling quadrats, the criteria of vegetation index score, classification of vegetation community, and grade criteria for vegetation assessment. The developed vegetation assessment indicator composed with the vegetation complexity index (VCI), the vegetation diversity index (VDI), and the vegetation naturalness index (VNI) was proved to reflect the current conditions of the streams sufficiently. The contribution of vegetation naturalness index to grading by vegetation assessment indicator was larger, but three indexes were closely correlated to each other. Also there was more clearer discrimination of grading with the application of adjusted criteria of vegetation assessment indicator and the standardized classification of vegetation community, but the stream segment type did not influence the vegetation assessment grade significantly.

Analysis of the vegetation effects on the flow in Chopyeong Island of the Imjin River using a HEC-RAS 2D model (HEC-RAS 2D 모형을 이용한 임진강 초평도 식생이 흐름에 미치는 영향 분석)

  • Lee, Du Hana;Rhee, Dong Sop
    • Journal of Korea Water Resources Association
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    • v.56 no.9
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    • pp.575-586
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    • 2023
  • River vegetation has important functions such as providing a habitat for the river ecosystem and physical stability of the river bank. It also has adverse effects such as aggravating flood damages due to the increase in roughness coefficient and drag forces. River vegetation management is very important in finding a balance between flood and ecological management. There are still many uncertainties about the effect of vegetation on rivers. In this study, in order to analyze the effect of vegetated flow, the flow patterns according to the vegetation roughness are analyzed through a two-dimensional unsteady flow model for Chopyeong island of the Imjin River. According to the results of the 2D flow analysis using the HEC-RAS 2D model, the velocity distribution in the bend of the Imjin River was greatly affected by the vegetation roughness of Chopyeong Island. The formation of the main flow outside the bend of Chopyeong Island during flooding is presumed due to the influence of tree and grass on Chopyeong Island. If tree are distributed throughout Chopyeong Island, the velocity outside the bend is expected to be higher. River vegetation causes the effect of raising the water level, and could cause a change in the velocity distribution.

Syntaxonomy and Synecology of the Robinia pseudoacacia Forests (아까시나무림의 군락분류와 군락생태)

  • Cho, Kwang-Jin;Kim, Jong-Won
    • The Korean Journal of Ecology
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    • v.28 no.1
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    • pp.15-23
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    • 2005
  • The black locust (Robinia pseudoacacia L.) forests were studied by a phytosociological approach. Particular attention was given to characterize the vegetation classification, distribution pattern, and ecological flora of the syntaxa classified. A total of 38 releves were analyzed by using Correlation coefficient, UPGMA as the clustering method, and Principal Coordinates Analysis for ordination. Ecological flora analyzed by plant character sets such as scrambler, annual and biennial plants, forest elements, and actual urbanization index. The analyzed data are based on site-releve matrix with relative net contribution degree (r-NCD) of species. A total of 77 families, 193 genera and 323 species of vascular plants are recorded. Camellino-Robinietum pseudoacaciae ass. nov. and Phragmites-Robinia pseudoacacia community were described. Main cluster and ordination could be separated: 1) urban type, 2) rural type, 3) riparian type, and 4) combined type. It is defined that the Robinietum is a representative unit on the black locust afforestation, Phragmites-Robinia community on the lentic zone in the river ecosystem, and Cameliino-Robinietum ailanthetosum altissimae as an urban forest type. The Robinietum was considered as a perpetual community.