• Title/Summary/Keyword: ORDINATION

Search Result 426, Processing Time 0.032 seconds

Diet Partitioning between Co-occurring Amblychaeturichthys hexanema and Amblychaeturichthys sciistius in the Southeastern Korean Waters (동해 남부 연안에 출현하는 도화망둑 (Amblychaeturichthys hexanema)과 수염문절(Amblychaeturichthys sciistius)의 먹이 분할)

  • Huh, Sung-Hoi;Park, Joo Myun;Baeck, Gun Wook
    • Korean Journal of Ichthyology
    • /
    • v.28 no.2
    • /
    • pp.79-86
    • /
    • 2016
  • Stomach contents of Amblychaeturichthys hexanema and A. sciistius (Perciformes: Gobiidae) from southeastern waters off Korea were analyzed to determine dietary habits and the presence of any inter- and intra-specific partitioning of food resources. These two species were bottom-feeding carnivores that consumed mainly benthic crustaceans, and other demersal invertebrates and planktonic organisms were also important in their diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on gravimetric contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences; i.e. partitioning of food resources between the two species. Size-related changes, however, were not significant for their diets. Differences in the types and range of prey ingested by the two species could often be related to differences in the feeding behaviors. Our results of stomach contents analyses provide clear evidence of niche segregation between co-occurring A. hexanema and A. sciistius in southeastern Korean waters, which would reduce the likelihood of inter-specific competition for food resources.

Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans in Marine Sediments from Mokpo Coastal Water of Korea

  • Moon, Hyo-Bang;Kang, Sung-Kyung;Seo, Won-Ju;Choi, Min-Kyu;Yu, Jun;Choi, Hee-Gu;Park, Jong-Soo
    • Fisheries and Aquatic Sciences
    • /
    • v.10 no.2
    • /
    • pp.93-101
    • /
    • 2007
  • Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in marine sediments from Mokpo coastal water of Korea. Total and toxic equivalent (TEQ) concentrations of PCDD/Fs ranged from 19.4 to 175pg/g dry weight and ranged from 0.195 to 2.87 pg WHO-TEQ/g dry weight, respectively. These PCDD/F concentrations were below the safety sediment value (20 pg TEQ/g dry weight) of chronic toxicity. A highly significant correlation between the concentrations of PCDD/Fs and total organic carbon (TOC) in marine sediments was observed. Overall PCDD/F concentrations in the sediments were elevated in rivers and at inner locations close to harbors, indicating that these contaminants derived from local discharges of human activities. PCDD/F concentrations measured in our study were lower than those in several industrialized areas in Korea. Nonparametric multidimensional scaling (MDS) ordination showed that combustion processes from industrial complexes are the major source of PCDD/Fs in Mokpo coastal water.

Native Plants Selection in Decomposed Granite Cut-slope - In case study on forest road of Chungcheong-do and Gyeongsangbuk-do - (화강암질 풍화토 절토비탈면의 자생식물 선정 - 충청도와 경상북도 임도를 중심으로 -)

  • Song, Ho-Kyung;Park, Gwan-Soo;Lee, Mi-Jeong;Kim, Hyo-Jeong;Ji, Yun-Ui;Lee, Joon-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.6 no.5
    • /
    • pp.48-58
    • /
    • 2003
  • This study was carried out to select proper species for early stage replantation in granite forest road cut-slope. From one to thirteen year elapsed forest roads in five regional areas of Chungcheong-do and Kyungsangbuk-do, sample plots were selected, and their vegetations and environmental factors were investigated. Soil organic matter, total nitrogen, soil moisture content, and bulk density in the granite weathering soils were below 0.5%, 0.02%, 10%, and above 1.2g/$cm^3$, respectively. The environmental factors affecting distribution of species in the granite forest road were the elapsed year, elevation, cut-slope aspect, and cut-slope. Sowing plants of Dactylis glomerata, Lolium perenne, and Eragrostis curvula were found in the early stage of forest road-cut. Annual herbs of Youngia denticulata, Erigeron annuus, etc. were found in the 2-3 years elasped forest road-cut. Perennial herbs of Artemisia princeps var. orientalis, Miscanthus sinensis, etc., parachute woody plants of Weigela subsessilis, Pinus densiflora, etc., and gravitative trees of Prunus sargentii, Lindera obtusiloba, Quercus sp., etc. were found in the forest road cut-slope after 3 years of road-cut. Leguma of Lespedeza cureata, Amorpha fruticosa, Lespedeza bicolor, Pueraria thunbergiana, Albizzia julibrissin, etc., herbs of Artemisia keiskeana, Artemisia princeps var. orientalis, Miscanthus sinensis, etc., and woody plants of Rubus crataegifolius, Weigela subsessilis, Zanthoxylum schinifolium, Pinus densiflora, etc. were considered as proper species for replantation in granite forest road cut-slope.

Vegetation Structures and Ecological Niche of Quercus serrata Forests (졸참나무림의 식생구조와 생태적지)

  • Lee, Mi-Jeong;Yee, Sun;Kim, Hyo-Jeong;Ji, Yun-Ui;Song, Ho-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.7 no.1
    • /
    • pp.50-58
    • /
    • 2004
  • The aim of this study was to characterize the forest vegetation structure and site of Quercus serrata forest for ecological forest management and ecological niche. The results are as follows : The chemical properties of Q. serrata forest soil were 0.24% of total nitrogen, 8.27 of organic matter, 74ppm of available phosphorous, 1.64(me/100g) of Ca, 0.22(me/100g) of Mg, 0.74(me/100g) of K and 9.3(me/100g) of cation exchangeable capacity. The dominant species in Quercus serrata forest were Quercus serrata, Quercus acutissima, Quercus variabilis, Quercus mongolica, Styrax obassia, Fraxinus rhynchophylla and Styrax japonica. DBH analysis showed that Quercus serrata seems to remain as a dominant species for the present because they had random distribution based on few of big individuality, many of small and middle individuality. But the Q. serrata community is competing with Q. mongolica and F. rhynchophylla, whose density of small individuality has increased. With the classification of TWINSPAN, Q. serrata forest was classified three groups, such as Q. serrata-Acer mono, Q. serrata, Q. serrata-Q. acutissima communities. The results of the correlation analysis of Q. serrata major communities and environment factors are as follows; Q. serrata-A. mono community was found relatively in high elevated and eastern and northern area that has relatively high percentage organic matter. Also Q. serrata community was found in high elevated and eastern and northern area that has high percentage organic matter. Q. serrata-Q. acutissima community was found in low elevated and southern and western area that has low percentage organic matter.

Management Methods and Vegetation Characteristics of Rhododendron mucronulatum Habitat in Mt. Biseul (비슬산 진달래나무군락지의 식생특성과 관리방안)

  • Park, In-Hwan;Cho, Kwang-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.15 no.3
    • /
    • pp.55-66
    • /
    • 2012
  • This study was carried out to investigate vegetation of Rhododendron mucronulatum habitat in Mt. Biseul to recommend basic information for synecological characteristics and management methods. The survey was carried out from May to July, 2011 and totally 46 vegetation data including 42 families 93 genera 108 species 16 varieties and 5 forma were collected and analyzed. Among the investigated 129 taxa, the numbers of rare plant resources were summarized as 19 taxa; The rare plants designated by Korea Forest Service, the specific plants by floristic region and the endemic plants were listed as 3 taxa, 15 taxa and 4 taxa, respectively. Rhododendron mucronulatum habitat of Mt. Biseul was classified into 3 plant communities (Carex lanceolata-Rhododendron mucronulatum community, Potentilla dickinsii-Selaginella rossii community, Carex lanceolata-Quercus mongolica community). Carex lanceolata-Rhododendron mucronulatum community was subdivided into Tripterygium regelii subunit and Miscanthus sinensis for. purpurascens subunit by human interference degree. And synecology, syndynamics, synchorology of these plant communities were identified, and Site-species ordination analysis by Principal Coordinate Analysis (PCoA) reflected that human impact, soil moisture condition were main ecological factors determining the distribution pattern of classified plant communities. Therefore these plant communities correspond to quite distinctive 4 habitat types : unstable-dry type=Miscanthus sinensis for. purpurascens subunit, unstable-moderate type=Tripterygium regelii subunit, stable-dry type=Potentilla dickinsii-Selaginella rossii community, stable-moderate type=Carex lanceolata-Quercus mongolica community. Finally, through the vegetational diagnosis, proper management methods such as a limit on the access of visitors, planting of native woody plants after removing unwanted vines or grass were suggested.

A Study on Environment Characteristics of the Angelica gigas Nakai Population (참당귀(Angelica gigas Nakai) 개체군의 환경 특성 분석)

  • Choo, Byung Kil;Ji, Yunui;Moon, Byeong Cheol;Lee, A-Yeong;Chun, Jin Mi;Yoon, Taesook;Kim, Ho Kyoung
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.12 no.1
    • /
    • pp.92-100
    • /
    • 2009
  • This study was carried out to investigate vegetation structure and soil properties of Angelica gigas population distributed in Jeombongsan, Bangtaesan, Odaesan, Gyebangsan and Jirisan. From August 2007 until September 2008, 5m${\times}$5m quadrat was established in native area of Angelica gigas in order to record a dominants and coverage, and soil factors at 20 sites. It was found that the altitude in the distributed areas for Angelica gigas population was 710m or more. Angelica gigas population was classified into Parasencio auriculata var. kamtschatical dominant population, Pseudostellaria palibiniana dominant population, Isodon excisus dominant population and typical dominant population. In the site of study, soil pH, electrical conductivity, soil organic matter, available phosphorous, and exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable natrium concentration and total nitrogen were ranged from 5.1~6.2, 0.1~0.79dS/m, 2.21~22.11%, 9.56~37.97mg/kg, 1.85~23.88cmol+/kg, 0.21~1.18cmol+/kg, 1.07~5.09cmol+/kg, 0.04~0.14cmol+/kg and 0.09~1.04% respectively. The Parasencio auriculata var. kamtschatical dominant population was found in area of high altitude and had high slope degree. But Pseudostellaria palibiniana dominant population was found in area of low altitude and low slope degree. Isodon excisus dominant population was found to have higher soil pH and exchangeable potassium concentration than the other dominant population.

Weed Vegetation Analysis by Two Dimensional Ordination Analysis Along the Waterway of Kyungnam and Kyungpook Provinces (경남북지역(慶南北地域) 수로변(水路邊)의 잡초식생(雜草植生)에 관(關)한 연구(硏究))

  • Kim, K.U.;Kwon, S.T.;K.W., Back;H.Y., Kim
    • Korean Journal of Weed Science
    • /
    • v.10 no.2
    • /
    • pp.75-82
    • /
    • 1990
  • Weed species investigated along the waterway of Kyungnam and Kyungpook provinces on September, 1989 were 88 species in 33 families and 96 species in 33 families, respectively. Three weed community types were observed along the waterway of Kyungnam province, namely, Echiuochoa cars-galli, Persicaria hydropiper and Persicaria thunbergii, and five community types such as Humulus japonicus-bideus froudosa, Solanum nigrum, Persicaria thunbergii-Humulus japonicus, Humulus japonicus and Persicaria thunbergii were detected along the waterway of Kyungpook province. The most dominant weed species indentified along the waterways in both Kyungnam and Kyungpook provinces were Pensicaria tlrutrheagii and Persicaria hydropiper which are the aquatic weed species.

  • PDF

More about Taxonomic Sufficiency: A Case Study using Polychaete Communities in a Subtropical Bay Moderately Affected by Urban Sewage

  • Muniz Pablo;Pires-Vanin Ana M. S.
    • Ocean Science Journal
    • /
    • v.40 no.3
    • /
    • pp.127-143
    • /
    • 2005
  • The taxonomic sufficiency approach has been proposed as a surrogate for the typical analysis of species-abundance data, especially in conditions involving prominent pollution gradients. Here, we evaluate the use of taxonomic sufficiency with infralittoral macrobenthic data derived from samples taken in a moderate polluted subtropical environment in southeastern Brazil, analysing five taxonomic levels and including two functional levels throughout polychaete feeding guilds and trophic groups. The data were collected seasonally at nine stations and studied for two abundance data series (0.5 and 1.0 mm sieve mesh-size). The results showed a similar ordination pattern between the two sieve mesh-size, but with the 0.5 mm sieve data a different pattern was observed during austral summer. A slight loss of information was detected using genus, family, polychaete species and their feeding guilds as taxonomic/functional units. These results together with those of the cost! benefit ratio, suggested that the family level seemed to be sufficient to detect the impact caused by moderate pollution in this shallow-water, subtropical environment. In additional, through the use of feeding guilds, similar patterns are obtained. Correlation analysis showed that chlorophyll a, total organic matter, zinc, and chromium sediment content were the variables that best explained the biological pattern observed and not always the best correlation coefficient occurring at the species level. The feeding guild approach seems to be useful and generates interpretable results similar to those obtained with the species level of the whole macroinfauna. The results showed an important cost reduction in the sample processing, suggesting that it is possible to adopt a coarser taxonomic level monitoring program even in species-rich communities.

Problems and Solving Strategies on Student Evaluation of Clinical Nursing Education (임상 간호교육 평가의 문제점과 개선방안)

  • Park, Jin-Mee;Chung, Young-Soon;Jung, Sung-Eun;Chung, Bok-Yae
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.8 no.1
    • /
    • pp.84-94
    • /
    • 2002
  • The purpose of this descriptive study was to identify problems and solving strategies on student evaluation of clinical nursing education. Subjects were 239 nurses in 18 hospitals from February to July, 1999. Content analysis using qualitative research method was used to analyze data taking into account the semi-structured questionnaire. The results of this study were as follows: Four categories about problems and solving strategies on the evaluation of clinical nursing education were identified: 'The environment of the clinical nursing education'; 'contents and items of evaluation tool'; 'criteria of evaluation tool'; and 'problems with evaluators in clinical settings'. The problems of the environment of the clinical nursing education were due to the lack of co-ordination between nursing schools and hospitals. In order to solve these problems, the following strategies were suggested: 'initiate a joint meeting between nursing schools and hospitals'; 'do not change the clinical settings frequently'; 'evaluate students after being familiar with them'; and 'evaluate them immediately after clinical practice was ended'. In the problems of contents and items of the evaluation tool, the contents of the tool were very abstract and general. The strategies for treating these problems were to evaluate student using the concrete evaluation items'; refrain from evaluation of nursing knowledge', develop the evaluation tools that are fit for a specific clinical setting'; develop the evaluation tools in line with students' knowledge level; and 'carry out evaluation using the proper contents of tool. The problems of criteria of the evaluation tools were the results of the lack of the clear criteria. The strategies for treating these problems were 'develop the criteria of the evaluation tool'; simplify the range of the cores or evaluate students using check-list'; to evaluate students in objective manner'. The problem of evaluators in clinical settings was due to the failure by evaluators who were not prepared for the task. The strategies were 'to educate and prepare the evaluators before evaluation'.

  • PDF

A DOUBLE-BLIND CLINICAL TRIAL OF PANAX GINSENG IN AGED SUBJECTS (이중 맹검법을 이용한 홍삼의 노인병 치료에 대한 임상연구)

  • Fulder Stephen;Kataria Mohan;Smith Beryl Gethyn
    • Proceedings of the Ginseng society Conference
    • /
    • 1984.09a
    • /
    • pp.215-223
    • /
    • 1984
  • Panax ginseng has often been suggested as a geriatric restorative. This study is a double blind crossover trial to test whether ginseng can improve function in subjects with the depression and reduced abilities associated with senescence. 49 screened subjects were given 1500 mg Korean Red ginseng and identical placebo each for ten days, with a washout period in between the dosages. Standard tests of mental function, neuromuscular reflexes, responsiveness, mood and well being were used. The subjects were somewhat better at the co-ordination and speed test ('number copying') but tests of concentration and memory ('Concentration', 'Paired Association', 'Digit Span' and 'Object Learning') gave equivocal results. There were small improvements in mood and well being ('Life Satisfaction' and 'General Health Questionnaire') while the subjects indicated increased energy, alertness and less sleep, but also less happiness on the daily analogue scales. The major result was a highly significant improvement in reactivity, speed and co-oridnation at the tapping test, and the visual, auditory and disjunctive reaction timer. These are the most objective and accurate tests used in this trial. It is therefore concluded that ginseng can increase function in senile individuals. This effect is most easily visualisable in objective psychophysical tests, rather than the more subjective memory and concentration tests.

  • PDF