• 제목/요약/키워드: Disturbance streams

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중·소하천에서 물리적 구조의 교란과 하안식생 귀화율의 관계 (The Relationship between Disturbances of Hydromorphological Structures and Naturalized Plants Ratio in Small and Mid-sized Streams)

  • 천예준;최윤의;홍선희;전진형
    • 한국환경복원기술학회지
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    • 제16권1호
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    • pp.207-225
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    • 2013
  • Current ecological stream restoration is focusing on recovery of physical characteristic and ecological functions of individual stream. For effective stream restoration, the relationship between stream environment and riparian flora should be investigated. The purpose of this study is to analyze the relationship between disturbance of hydromorphological structures and naturalized plants ratio in small to mid-sized streams. For the study sites, Gwanpyeong stream, Dongdal stream, and Yongchoo streams were chosen as 'reference stream' while, Gunnam stream, Anchang stream, and Hwa stream were chosen as 'damaged stream'. The hydromorphological structures of streams were evaluated with LAWA and flora of the streams were completely enumerated to calculate naturalized plants ratio. The result showed that there was a significant correlation between the outcome of LAWA and naturalized plants ratio(r=0.675, p<0.01). The result of factor analysis of LAWA identified three factors, 'River front and land use', 'River bed materials and structures', and 'Crossing structure and bar'. Among the factors of hydromorphological structures given by the result of factor analysis, 'river front and land use' and 'bed materials and structures' have statistically significant relationship with naturalized plants ratio($R^2$=0.470, p<0.01). Given this results, quantitative analysis on the relationship between disturbance of hydromorphological structures of streams and naturalized plants ratio could provide some essential information for stream restoration. Also, as this study figured out major factors of hydromorphological structures that affect naturalized plants ratio, it might help monitor ecological states and current problems of small and mid-sized streams.

RAPD 분석에 의한 고마리(마디풀과)의 유전적 변이 및 유연관계 (Genetic Variations and Relationships of Persicaria thunbergii(Sieb. & Zucc.) H. Gross ex Nakai(Polygonaceae) by the RAPD Analysis)

  • 김용현;태경환;김주환
    • 한국자원식물학회지
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    • 제21권1호
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    • pp.66-72
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    • 2008
  • 고마리의 24개 지역집단으로부터 PCR을 통한 RAPD 분석을 실시하였다. PCR을 통해 증폭된 RAPD절편들은 200-1, 900bp 사이의 구간에서 관찰되었다. 총 16개의 oligoprimer를 이용한 효소중합반응에서 184개의 유효한 polymorphic band markers를 확인하였다. RAPD 분석결과를 기초로 UPGMA 방법에 의한 유집분석을 수행한 결과, 고마리 개체군은 교란형 하천(도시하천, 농촌하천)과 자연적 수환경으로 유집되었고, 교란형 하천 보다 자연적 수환경의 고마리 개체군끼리 유전적 유연관계가 높은 것으로 나타났다. 또한 자연적 수환경과 교란형 하천에 생육하는 고마리 개체군간에 뚜렷한 유전적 한계를 나타내어 이들 사이의 유전적 이질성이 있는 것으로 생각된다.

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
    • 한국환경생태학회지
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    • 제29권2호
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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.

내성천 유역 하천의 물리 서식지 특성 평가 (Assessment of Physical Habitats Characteristics in Naeseongcheon Basin Streams, Korea)

  • 김기흥;정혜련;홍일;여홍구
    • Ecology and Resilient Infrastructure
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    • 제10권4호
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    • pp.143-160
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    • 2023
  • 본 연구는 내성천 유역의 급경사 및 중경사 하천에 하천복원 및 유역관리를 위한 기본 정보를 얻기 위해 하천의 물리 서식지 평가체계를 적용했다. 평가결과 내성천 유역의 급경사 및 중경사 하천 총연장은 약 273 km이며, 이 중에서 우수 약 8.2 km, 보통 180.3 km, 한계 84.7 km인 것으로 분석되었다. 또한 급경사 하천 전체의 물리 서식지 질은 평균 106점 (53%)으로 보통 등급이며, 특히 수서 동물의 서식처에 가장 중요한 하도/수리 영역은 평균 54점 (45%)으로 한계상태에 가까운 보통 등급인 것으로 분석되었다. 중경사 하천 물리 서식지 질은 평균 90점 (45%) 보통 등급이며, 하도/수리 영역 평균 39점 (32%) 한계상태로 나타났다. 전반적으로 내성천 유역의 급경사 및 중경사 하천 165개 구간 중 우수 4개 (3%), 보통 119개 (72%) 및 한계 42개 (25%) 구간으로 평가되었다. 이러한 결과는 내성천의 물리 서식지가 상당히 교란되었음을 보여준다. 내성천 유역의 하천 물리 서식지 교란은 하천주변의 경작지, 도시화, 저수지 건설 및 하천정비 등으로 발생하였다.

골채채취 후 수변환경 변화와 사주 내 식생이입 (Riparian Environment Change and Vegetation Immigration in Sandbar after Sand Mining)

  • 공학양;김세미;이재윤;이재안;조형진
    • 한국물환경학회지
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    • 제32권2호
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    • pp.135-141
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    • 2016
  • This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

Individual-Based Models Applied to Species Abundance Patterns in Benthic Macroinvertebrate Communities in Streams in Response to Pollution

  • Cho, Woon-Seok;Nguyen, Tuyen Van;Chon, Tae-Soo
    • 생태와환경
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    • 제45권4호
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    • pp.420-443
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    • 2012
  • An Individual-Based Model (IBM) was developed by employing natural and toxic survival rates of individuals to elucidate the community responses of benthic macroin-vertebrates to anthropogenic disturbance in the streams. Experimental models (dose-response and relative sensitivity) and mathematical models (power law and negative exponential distribution) were applied to determinate the individual survival rates due to acute toxicity in stressful conditions. A power law was additionally used to present the natural survival rate. Life events, covering movement, exposure to contaminants, death and reproduction, were simulated in the IBM at the individual level in small (1 m) and short (1 week) scales to produce species abundance distributions (SADs) at the community level in large (5 km) and long (1~2 years) scales. Consequently, the SADs, such as geometric series, log-series, and log-normal distribution, were accordingly observed at severely (Biological Monitoring Working Party (BMWP<10), intermediately (BMWP<40) and weakly (BMWP${\geq}50$) polluted sites. The results from a power law and negative exponential distribution were suitably fitted to the field data across the different levels of pollution, according to the Kolmogorov-Smirnov test. The IBMs incorporating natural and toxic survival rates in individuals were useful for presenting community responses to disturbances and could be utilized as an integrative tool to elucidate community establishment processes in benthic macroin-vertebrates in the streams.

정량화에 의한 물리적 하천교란 평가기법의 개선과 적용 (An Improvement and Applicability of Physical Disturbance Evaluation Technique by Quantification in River System)

  • 최흥식;심규랑;이웅희
    • 한국습지학회지
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    • 제17권3호
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    • pp.209-220
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    • 2015
  • 본 연구에서는 기존의 물리적 하천교란 평가방법을 개선하고 적용성을 분석하였다. 개선한 교란평가 기법은 정성적 항목을 정량적인 항목으로 제시하고 이의 근거와 평가 산정식을 제시하였고, 이에 상응하는 평가영역 내 점수를 보다 세분화 하고 수리특성과 지형 변화를 수치모의에 의한 결과를 이용할 수 있도록 개선하였다. 개선된 교란평가방법은 적용성을 확인하기 위해 비정비하천, 도시관류하천, 산지계류하천의 특성을 가지는 6개의 하천에 적용하여 기존의 평가방법과 개선된 평가방법의 결과를 비교 분석하였다. 하상서식환경과 하상재료를 제외한 8가지 평가항목은 HEC-RAS 수치모의 결과를 직접 입력하여 간편하게 수행할 수 있었다. 또한 정량적 평가방법의 적용 결과 기존의 평가방법보다 민감한 평가 결과를 나타냈으나, 전반적으로 기존의 평가방법과 비슷한 결과를 나타내어 적용성이 있음을 확인하였다.

비술나무(Ulmus pumila L.) 군락의 재정착과 발달 특성 (Community Regeneration and Development Traits of Ulmus pumila L.)

  • 김영철;채현희;홍보람
    • 한국환경생태학회지
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    • 제37권1호
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    • pp.13-34
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    • 2023
  • Many ecologists try to understand plant communities and societies' changing processes by interacting with environmental factors. Plant communities formed in the sidings of streams, which are more dynamic than forest vegetation, are closely related to the disturbance regime of streams. U. pumila, which forms communities at the edges of streams, is distributed over the central and northern regions of the Korean Peninsula. In this study, we intended to explain the regeneration of U. pumila communities in the upstream region of the Namhangang River. Heights from the stream surface to the mid-high points of communities increased when the age class of U. pumila communities increased. On the other hand, the height of U. pumila tended to increase and decrease as the age class increased. The richness (S), evenness (J'), diversity (H'), and maximum diversity (H'max) also showed a tendency to increase and then decrease as the age class increased. On the other hand, the number of stems per individual and density (D) decreased as the age class increased. Seedlings of U. pumila failed to regenerate in the communities at the intermediate or higher stage of the age class. Regeneration of seedlings occurred in the spaces formed by the flooding, which occurred periodically in streams. After regeneration, U. pumila communities grew like a single organism. On the other hand, the plant species consisting of U. pumila communities exhibited a process in which the S and H' increased and then decreased as they developed. In other words, we determined that the changes in the species compositions were associated with changes in each species' environment and community. A space where seeds can regenerate seedlings should be provided for the regeneration of U. pumila communities. In the mid/upstream region of the Namhangang River, where the present study focused, newly formed communities were rare because the space required to regenerate U. pumila ceased to exist. Accordingly, we suggest securing an appropriate space for the regeneration of seedlings to maintain the U. pumila communities in the upstream region of the Namhangang River.

생태적 진단결과에 기초한 창원천과 남천의 복원계획 (Restoration Plan of Changwon and Nam Streams Based on the Results of Diagnostic Assessment)

  • 안지홍;임치홍;정성희;김아름;우동민;이창석
    • 한국물환경학회지
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    • 제33권5호
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    • pp.511-524
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    • 2017
  • This study was carried out for the purpose of creating a restoration plan to improve the ecological quality of the Changwon and Nam streams. Based upon the results of comprehensive diagnostic assessment, restoration priority was given to the upstream reach, where conservation status is relatively superior. Restoration level was usually determined to practice active restoration as conservation, and the states of both Changwon and Nam streams were not so good. Restoration plans, by reach, were classified into "upstream", "midstream", and "downstream" were suggested in both terms of horizontal section frame and vegetation-based on the result of diagnostic assessment and the reference information. "Upstream", "mid-stream" and the "downstream" of Changwon and Nam streams were classified into "small-gravel- mountainous", "small-sand-plain", and "small-clay-plain streams" respectively (based on scale, and substrate and slope of river bed). The spatial arrangement of vegetation was laid out in diagram form by reflecting micro-topography and the water level of the horizontal section of river. Information regarding species composition was recommended as dominant species, which appear frequently in three vegetation zones composed of herbaceous plants, shrubs and trees and sub-tree- dominated zones divided by reflecting disturbance regime, depending on position on the horizontal section of river. Moreover, there have been prepared not only plans to improve the terrestrial ecosystems around the streams but also plans to create ecological networks, which can serve to improve the ecologic quality of the whole regional environment by serving to connect streams and terrestrial ecosystems, a process probably necessary and definitely recommended to realize true (genuine) restoration. Plans for ecological parks and networks were prepared by mimicking the species composition of Alnus japanica community, Zelkova serrata community, Carpinus laxiflora community, Quercus aliena community, and Q. serrata community.