• Title/Summary/Keyword: Important species

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Comparative Study of Volatile Organic Compound Concentrations in the Yochon Industrial Estate during Spring and Fall (여천 공업단지 봄, 가을 대기 중 휘발성 유기화합물 농도 비교 연구)

  • 김영성;송철한
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.2
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    • pp.153-160
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    • 1998
  • The concentrations of volatile organic compounds (VOCs) in the atmosphere were measured from the Yochon Industrial Estate and compared with those from Tongkwangyang and Seoul. The first important phenomenon observed in the air of Yochon was high concentrations of alkenes and in particular, ethylene and propene. For most dominant species, their means and standard deviations were high simultaneously. Concentrations of several major aliphatic species exhibited a similar pattern of diurnal variation, however, with different species combination on each day. Concentrations of several hazardous aromatic species also exhibited a similar pattern of diurnal variation on the same day, which was different from that observed in the diurnal variation of major aliphatic species. It was interpreted that some species were intermittently released from relevant processes. It was also understood that high concentrations and variations of VOC species in Yochon were localized and not related to high average concentrations of ozone in Yochon and Tongkwangyang areas.

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New record of three aquatic species of Enchytraeidae (Annelida: Clitellata) from Korea

  • Lee, Jeounghee;Jung, Jongwoo
    • Journal of Species Research
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    • v.5 no.3
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    • pp.541-546
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    • 2016
  • Enchytraeidae is one of the largest groups in Clitellata. They are commonly found in soil and aquatic environments and play important roles in these ecosystems. It is not easy to study enchytraeid clitellates because of difficulty in distinguishing morphologies between closely related species. In Korea, 29 species have been reported in this family. Of these, 27 species are terrestrial and only two species are aquatic. Here, we report three aquatic enchytraeid species new to Korea: Fridericia glandifera Friend, 1913, Henlea montana Rota, 1994 and Marionina brendae Bretscher, 1899.

Sciaphila secundiflora Thwaites ex Benth. (Triuridaceae): An unrecorded species from Korean flora

  • Yim, Eun-Young;Hyun, Hwa-Ja;Kim, Chang-Uk;Kim, Chan-Soo
    • Korean Journal of Plant Taxonomy
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    • v.47 no.3
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    • pp.196-198
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    • 2017
  • Sciaphila secundiflora occurs on Jeju Island as a second species of the genus Sciaphila in Korea. This is an important finding in relation to the flora of Korea, as species of the genus Sciaphila are concentrated mainly in Indonesia and Malaysia. Few species are found on the mainland of Asia, in Japan, Taiwan, China (Hainan), tropical Africa, Australia, and on the Pacific islands. In this paper, the species S. secundiflora is described and illustrated as a new record from Korea. In addition, we suggest that the species of the genus Sciaphila should be protected with regard to its habitat characteristics and for its phytogeographic and climatic significance.

Two Unrecorded Species of the Genus Atherigona (Diptera: Muscidae) from Korea

  • Young-Kun Kim;Dongmin Kim;Sang Jae Suh
    • Animal Systematics, Evolution and Diversity
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    • v.39 no.3
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    • pp.92-98
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    • 2023
  • Larvae of shoot flies are known to live on decaying plants or to infest the stems of wild and crop plants. Among them, some species are economically very important pests that damage fruits or cereal crops in Old world tropics and subtropics. In Korea, three species, Atherigona orientalis, A. oryzae, and A. soccata, are managed as quarantine pests. To date, a total of five species, A. (Acritochaeta) orientalis Schiner, A. (Atherigona) bifurca Suh and Kwon, A. (A.) biseta Karl, A. (A.) falcata (Thomson) and A. (A.) oryzae Malloch, including two quarantine pests, have been recorded in Korean fauna. During the survey of Korean houseflies, the authors discovered two new unrecorded species, A. (A.) miliaceae Malloch and A. (A.) reversura Villeneuve. The diagnoses and illustrations of these species are provided in addition to the key to the Korean Atherigona species.

Comparison of Frequencies in Order to Estimate of Tree Species Diversity in Caspian Forests of Iran

  • Mirzaei, Mehrdad;Bahnemiry, Atefeh Karimiyan;Abkenar, Kambiz Taheri
    • Journal of Forest and Environmental Science
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    • v.35 no.1
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    • pp.1-5
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    • 2019
  • Species diversity is one of the most important indices that used to evaluate the sustainability of forest communities. In the present study, three variables including number of individuals (frequency of species), basal area and volume of tree species were compared to estimate tree species diversity in broadleaves forests of Iran. Based on systematic random design, 30 plots (circle plot, $1000m^2$) was selected. Type of species, number of species, DBH and height of trees were measured. Simpson (1-D), Hill ($N_2$), Shannon-Wiener (H'), Mc Arthur ($N_1$), Smith-Wilson ($E_{var}$) and Margalef ($R_1$) indices used to estimate tree species diversity. Species diversity was calculated in each plot. ANOVA test showed that there was a significant difference between of three variables used for estimation of species diversity. Number of trees variable has more precision than basal area and volume variables to estimate of species diversity. But Duncan test revealed that there were significant difference between of basal area and volume variables with number of trees. Therefore, basal area and volume variables were selected as more suitable variables in order to estimate of biodiversity indices in northern forests of Iran.

Contrasting Zooplankton Community Structure in Sandusky Bay and Lake Erie (Sandusky Bay 와 Lake Erie 의 상이한 동물 플랑크톤 군집의 구조에 대하여)

  • Hwang, Soon-Jin;Robert T. Heath;Ralph J. Garono
    • The Korean Journal of Ecology
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    • v.19 no.6
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    • pp.543-562
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    • 1996
  • Zooplankton community structure and the factors correlated with community differences were examined in sandusky Bay (SB) and the open water of Lake Erie (LE, U.S.A.). SB zooplankton communities differed from those in LE by having a greater rotifer density and species richness. Keratella spp., Brachionus spp., and Pompholyx complanata dominated SB rotifers; Brachionus and Pompholyx were rarely seen in LE. Of 19 rotifer species observed, nine species were found only at SB sites. Ordination of zooplankton species abundance by detrended correspondence analysis (DCA) showed an overlap between SB and LE sites, but indicated a portion of the space that was occupied by only SB communities. The seasonal trajectories of zooplankton dynamics in the ordination space at SB sites differed from that of LE. The zooplankton most important in forcing site separation along a DCA Axis I at SB sites were Brachionus angularis, Pompholyx complanata, Keratella valga, Keratella quadrata, Filinia terminalis (rotifers), and Eubosmina coregoni and Daphnia (cladocerans). These species had axis scores which were significantly correlated (p<0.01) with bacterial density and bacterial phosphorus, total phosphorus, and algal density. Very high baterial density and very abundant bacterivorous rotifers in SB suggest that the transport of bacterial carbon through rotifers may be a relatively important link to higher trophic leaels. We believe that this "microbial carbon flow" from the base of the food web may be important in determining the suitability of SB as a spawning site and nursery for larval and juvenile fish.nile fish.

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Co-occurrence Patterns of Bird Species in the World

  • Kim, Young Min;Hong, Sungwon;Lee, Yu Seong;Oh, Ki Cheol;Kim, Gu Yeon;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.50 no.4
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    • pp.478-482
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    • 2017
  • In order to identify key nations and bird species of conservation concern we described multinational collaborations as defined using network analysis linked by birds that are found in all nations in the network. We used network analysis to assess the patterns in bird occurrence for 10,422 bird inventories from 244 countries and territories. Nations that are important in multinational collaborations for bird conservation were assessed using the centrality measures, closeness and betweenness centrality. Countries important for the multinational collaboration of bird conservation were examined based on their centrality measures, which included closeness and betweenness centralities. Comparatively, the co-occurrence network was divided into four groups that reveal different biogeographical structures. A group with higher closeness centrality included countries in southern Africa and had the potential to affect species in many other countries. Birds in countries in Asia, Australia and the South Pacific that are important to the cohesiveness of the global network had a higher score of betweenness centrality. Countries that had higher numbers of bird species and more extensively distributed bird species had higher centrality scores; in these countries, birds may act as excellent indicators of trends in the co-occurrence bird network. For effective bird conservation in the world, much stronger coordination among countries is required. Bird co-occurrence patterns can provide a suitable and powerful framework for understanding the complexity of co-occurrence patterns and consequences for multinational collaborations on bird conservation.

Effect of Environmental Variables on Changes in Macrobenthic Communities in the Coastal Area of Inchon, Korea (인천연안 대형저서동물 군집 변동에 미치는 환경요인의 영향)

  • YU Ok Hwan;KOH Byoung-Seol;LEE Hyung-Gon;LEE Jae-Hac
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.5
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    • pp.423-432
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    • 2004
  • In coastal area of Inchon, dredging and the disposal of dredged material for sea-wall construction and reclamation have increased in recent years. These activities may impact the benthic environment and result in changes in benthic communities, but little information is available on the extent and direction of these changes. We investigated whether there have been changes in the dominant macrobenthic species and benthic community over the last decade, and explored the relationship between environmental variables and spatial patterns of macrobenthic community structure. We sampled macrobenthos and recorded environmental variables in the coastal habitats of Inchon in March and June 2004. In total, 212 macrobenthic species were recorded during this study, predominately crustaceans $(34{\%})$, mollusks $(32{\%})$ and polychaetes $(21{\%})$. The mean density of macrobenthos was $1,393\;ind./m^{2}$.The most abundant species was Amphioplus japonicus $(20.5{\%})$, followed by Heteromastus filiformis $(14.4{\%})$, Theora fragilis $(8.2{\%})$ and Ampharete sp. $(4.0{\%})$. Over the past decade the dominant macrobenthic species in this area shifted. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among three regions: the middle part of the sampling area (B), site 8 (C) and other sites (A). Mean density varied significantly among the three regions, but no differences in the number of species and diversity (H') were observed. The distribution of the macrobenthic community was affected by environmental variables such as percentage sand content and sediment kurtosis. Species that were important in different areas included A. japonicus in region A, Raeta puchella in region B and T. fragilis in region C. The important species in regions B and C were filter-feeding bivalves, and the abundance of these species may be related to the increase in percentage sand content. We suggest that the sediment composition (percentage sand content) may be an important factor in determining the dominant species and structure of the macrobenthic communities in coastal Inchon. Long-term monitoring programs are necessary to understand ongoing changes in the benthic communities of this area.

Evaluation of Habitat Suitability of Honey Tree Species, Kalopanax septemlobus Koidz., Tilia amurensis Rupr. and Styrax obassis Siebold & Z ucc. in the Baekdudaegan Mountains using MaxEnt Model (MaxEnt 모형을 활용한 백두대간에 자생하는 주요 밀원수종인 음나무, 피나무, 쪽동백나무의 서식지 적합성 평가)

  • Sim, Hyung Seok;Lee, Min-Ki;Lee, Chang-Bae
    • Journal of Korean Society of Forest Science
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    • v.111 no.1
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    • pp.50-60
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    • 2022
  • In this study, habitat suitability was analyzed for three major honey tree species, namely Kalopanax septemlobus, Tilia amurensis, and Styrax obassis, in the Baekdudaegan Mountains using MaxEnt models. The AUC values indicating the prediction accuracies of the models were 0.747, 0.790, and 0.755 for K. septemlobus, T. amurensis, and S. obassis, respectively. The most important variables for K. septemlobus and T. amurensis were elevation, mean annual temperature, and slope, whereas mean annual temperature, elevation, and mean annual precipitation were the most important predictors for S. obassis. For all three studied species, elevation and mean annual temperature were the most important topographic and climatic factors, respectively, indicating that such variables are crucial for explaining species distribution. Honey tree species are essential resources in forest beekeeping, a high value-added process for improving forest income, and this study identified sites with the potential for management of such species in the Baekdudaegan Mountains, where it may be possible to establish a honey forest. However, the accuracy of the models should be improved through comprehensive analysis with abiotic variables, such as soil properties and aridity, which affect the distribution of honey tree species, as well as biotic variables, such as interspecific competition.

Ecological Studies on Togyo Reservoir in Chulwon, Korea. 8. The Epilithic Algal Community after the Experimental Acidification on the Artificial Substrata (Tiles) at Mesocosm

  • Lee, Kyung;Yoon, Sook-Kyung;Ki, Jang-Seu;Han, Myung-Soo
    • ALGAE
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    • v.19 no.2
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    • pp.115-122
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    • 2004
  • The epilithic algal communities on the artificial substrata (unglazed ceramic tiles) were investigated from 5th July to 24th July 1999 with two or three days intervals for elucidating the effects of the experimental acidification. They were harvested inside the mesocosm with and without the acid treatment on Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. After the colonization of epilithic algal community, their standing crops revealed different patterns outside and inside the mesocosm. However the time lapse of 5 days was observed on the inside with acid treatment. The dominant species were different: Achnanthes minutissima was outside but Coenochloris polycocca was inside and inside with acid treatment. The differences in floral composition were also found. Achnanthes minutissima which has been the most important species in the colonization by the epilithic algal community of the mesocosm was less important at the lower pH. Coenochloris polycocca is a species well adapted to low pH.