• Title/Summary/Keyword: Species composition and structure

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Impact Assessment Model of Bird Species for Land Developments (개발사업에 따른 조류종 영향평가모형 개발 및 적용)

  • Lee, Dong-Kun;Kim, Eun-Young;Lee, Eun-Jae;Song, Won-Kyong
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.347-356
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    • 2010
  • Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

Early Changes in Vegetation after the Construction of 'the Ecological Forest' in Youido Park (여의도공원 내 조성된 '자연생태의 숲'의 초기 식생 변화)

  • Lee, Sang Won;Kim, Dong Yeob
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.1
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    • pp.41-51
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    • 2001
  • 'The Ecological Forest' in Youido Park was intended to be an artificial forest in urban center, following the form of natural forests in central Korea. This study was to investigate the planting plan and the vegetation change of 'the Ecological Forest' and to compare it with natural forests of similar plant composition. The natural forests had slopes between $12^{\circ}$ and $21^{\circ}$, whereas 'the Ecological Forest' had slopes between $2^{\circ}$ and $6^{\circ}$. It was unlikely that the slope condition was adequate to show 'toposequence succession' at 'the Ecological Forest'. The soil bulk density and soil hardness of 'the Ecological Forest' were higher than those of the natural forests. The soil pH of 'the Ecological Forest' was 7.45, which was greater than that of the natural forests. There were some changes in plant composition and amounts 2 years after the construction : the number of conifers was reduced from 383 to 338 ; the number of deciduous trees was reduced from 4717 to 1158. It was because of the young trees dead in the sub-tree layer. The herbaceous species planted were 14 families, 31 species, which increased to 37 families, 93 species after 2 years. In case of horizontal structure of vegetation, trees and shrubs were distributed evenly in the natural forests, whereas 'the Ecological Forest' showed uneven distribution with higher total density. In case of vertical structure of vegetation, the natural forests had distinctive layers with dominant species distributed in each layers. In 'the Ecological Forest', however, dominant species were only in tree layer. The natural forests had greater average tree height, tree density, however, and basal area than 'the Ecological Forest'. The results showed that there were some differences in the structure between 'the Ecological Forest' and natural forests. The management plan should be applied in order that the natural condition be restored in 'the Ecological Forest' by competition between plant species and natural processes.

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Diverse and predominantly sub-adult Epinephelus sp. groupers from small-scale fisheries in South Sulawesi, Indonesia

  • Nadiarti Nurdin Kadir;Aidah A. Ala Husain;Dody Priosambodo;Muhammad Jamal;Irmawati;Indrabayu;Abigail Mary Moore
    • Fisheries and Aquatic Sciences
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    • v.26 no.6
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    • pp.380-392
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    • 2023
  • Groupers (Family Epinephelidae) are commonly caught in data-poor small-scale multi-species fisheries for sale on both export and domestic markets. This study presents data on the species composition and size/life-stage structure of Epinephelus spp. groupers caught by small-scale fishers and sold locally in the Indonesian province of South Sulawesi. Data were collected from fishing ports and local markets at 12 sites representing the three seaways around South Sulawesi (Makassar Strait, Flores Sea, Gulf of Bone). Each specimen (n = 3,398) was photographed alongside an object of known length, and total length (TL) was obtained using the Rapid Scaling on Object (RASIO). Of the 23 species identified, four (Epinephelus areolatus, Epinephelus ongus, Epinephelus quoyanus, and Epinephelus fasciatus) collectively comprised 69% of the catch, while the 13 least abundant species contributed less than 5%. The catch was dominated (67%) by the subadult life-stage, with just under 20% in the adult class. Juveniles dominated the catch of Epinephelus fuscoguttatus, a valuable export commodity. Observations of early maturity as well as the sizeable gap between length at first capture (Lc) and length at first maturity (Lm) indicate recruitment overfishing of most species, with the notable exception of Epinephelus rivulatus. The proportion of adult fish was low (≈5%-30%) for the twelve most abundant species (E. areolatus, E. ongus, Epinephelus quoyanus, E. fasciatus, Epinephelus coioides, Epinephelus faveatus, Epinephelus sexfasciatus, Epinephelus maculatus, Epinephelus bleekeri, Epinephelus corallicola, E. fuscoguttatus, Epinephelus polyphekadion). For two moderately abundant species (E. faveatus and E. malabaricus), TL < Lm for all specimens. The limited data available indicate spawning ratio is lower than reported from deep-water fisheries of E. areolatus and E. coioides. The results call for targeted research to fill knowledge gaps regarding the biology and ecology of groupers exploited mainly for domestic markets; highlight the need for species-level data to inform management policies such as minimum legal size regulations; and can contribute towards species-level status assessments.

Seasonal Dynamics of Marine Benthic Communities in Intertidal Zone of Gwangyang Bay, Southern Coast of Korea

  • Yoo, Jong-Su
    • Ocean and Polar Research
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    • v.25 no.4
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    • pp.519-528
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    • 2003
  • Species composition and community structure of marine benthic community were studied in the intertidal zone of Jijindo Island, Gwangyang Bay. A total of 85 species of benthic marine plants including the 5 Cyanophyta, 9 Chlorophyta, 13 Phaeophyta, 56 Rhodophyta and 2 Magnoliophyta that were listed. The community structure was represented by Gelidium divaricatum in the upper zone, Celidium divalicatum and Ulva pertusa in the middle, and Ulva pertusa, Chondria crassicaulis, Chondracanthus intermedia and Sargassum thunbergii in the lower intertidal zone. The dominant species in the rnscro-zoobenthic community were Chthamalux challengeri in the upper and middle, Littorina brevicula between the upper and middle, and Mytilus edulis and Crassostrea gigas in the middle and lower intertidal zones. The economic benthic organisms such as Undaria pinnatifida, Mytilus edulis, and Crassostrea gigas found in the lower intertidal zone were frequently disturbed due to their collection by local resident. Therefore, it is necessary to record the correct information pertaining to these cases. The species diversity indices estimated kom different sources were quite different. They were 2.22 derived from frequency, 1.67 based on coverage, 2.17 based on sum of frequency and coverage and 2.04 derived from importance value. Species diversity and number of algal species in Gwangyang Bay have noticeably decreased, compared with their previously reported status. It is estimated that their decreases were caused by changes in the marine environment, especially pertaining to the polychaete community resulting from reclamation and dredging activity undertaken for the industrial development.

Structure of the Subtidal Marine Plant Community on the East Coast of Korea (한국 동해안 조하대 해산식물의 군집구조)

  • Shin, Jae-Deok;Ahn, Jung-Kwan;Kim, Young-Hwan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.1
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    • pp.85-94
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    • 2011
  • The species composition and distributions of benthic marine plants on the East Coast of Korea were studied. We examined all species found in the intertidal and subtidal zones at four sites seasonally from August 2006 to May 2009. Of the 148 species identified, 92 were rhodophytes, 39 were phaeophytes, 16 were chlorophytes, and 1 was a seagrass. The most species (125) were found at Jukbyeon, while the fewest (99) were found at Chuksan. Overall, the numbers of species were highest during the spring and lowest in autumn. Seventy-five species (50 rhodophytes, 15 phaeophytes, 9 chlorophytes, and 1 seagrass) were found at all four sites. The dominant species providing cover were melobesioidean algae, Sargassum spp., Phyllospadix japonica, and Corallina pilulifera. The vertical distribution of benthic marine plants was characterized by C. pilulifera, Sargassum spp., Hizikia fusiformis, Grateloupia elliptica, Symphyocladia latiuscula, Grateloupia lanceolata, Ulva pertusa, and Chondria crassicaulis in the intertidal zone; Sargassum spp., P. japonica, Prionitis cornea, C. pilulifera, and Acrosorium polyneurum at 1 m depth; Sargassum spp., P. japonica, and melobesioidean algae at 5 m depth; and melobesioidean algae at 10 m depth. There was variation among the sites, presumably due to differences in the local conditions.

Chemical Compositio and Structure of Evaporated Alloying Element by Laser Welding Condition (레이저 용접조건에 따른 증발된 합금원소의 조성과 구조의 변화)

  • 조상명
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.4
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    • pp.523-532
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    • 1999
  • This study is aimed to obtain fundamental knowledge of pulse laser welding phenomena the authors investigated the structure and composition of evaporated particles of Al alloys in air and in the Ar atmosphere during pulsed laser welding. The ultra-fine particles of 5 to 100nm diameter in a globular or irregular shape were formed in laser-induced plasma and the main structure was $MgAl_2O_4$ The composition of particles was ifferent depending on the power density of a laser beam; namely under the low power density conditions magnesium was predominant in the parti-cles while aluminium content increased with an increase in the power density. These results were attributed to evaporation phenomena of metals with different boiling points and latent heats of vaporization. On the other hand the number density of laser-induced plasma species was obtained by Saha's equation. it was confirmed that the number density depends upon the plasma tempera-ture and total pressures.

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Structure and Management Plan of the Spontaneous Herbaceous Communities in Midongsan Arboretum, Chungcheongbuk-do (충청북도 미동산수목원의 자생 초본군락 구조 및 관리방안)

  • You Ju-Han;Jung Sung-Gwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.2 s.109
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    • pp.48-59
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    • 2005
  • The purpose of this study was to examine the ecological characteristics of herbaceous communities by systematic and scientific analysis of their structure and diversity in the Midongsan Arboretum and to offer raw data for a long-tenn monitoring study. The importance value and diversity index of species appearing in twenty plots from July to September, 2004 were analyzed and a management plan for these communities is presented. Vascular plants were represented by 60 taxa of 23 families, 51 genera, 50 species and 10 varieties. Based on the results of importance value analysis, the most dominant species was Artemisia princeps var. orientalis, followed by Setaria viridis and Erigeron canadensis. The diversity index analysis showed that plot no. 5 had the highest H' and H'_{max}$(2.0135 and 2.6391). It's species composition was comparatively more diverse and it's structure more stable than other plots. Artemisia montana and Dactylis glomerata showed the highest correlation between species. Because herbaceous communities are important biological habitats and provide important function in environmental conservation, it is important to properly preserve these communities. At the same time, in order to preserve genetic resources and improve spatial function, it may be necessary to consider removing herbaceous communities in certain areas. In the future, the relations between physicochemical soil properties and herbaceous communities should be examined and community movement should be studied.

Structure of Intertidal Macroalgal Community at the Yeonpyeongdo Islets, Korea

  • Choi, Han-Gil;Yoo, Hyun-Il;Song, Hong-In
    • Fisheries and Aquatic Sciences
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    • v.11 no.3
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    • pp.159-165
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    • 2008
  • Intertidal benthic algal communities on the shores of Gujido and Daeyeonpyeongdo islets, Korea, were examined in October 2007. At both sites, 45 seaweeds including 7 green, 6 brown and 32 red algae were identified. The number of species at Gujido(38 species) was 1.5 times higher than at Daeyeonpyeongdo(25 species), but seaweed coverage was very similar with about 20%. Dominant seaweeds in terms of coverage and importance value were Hildenbrandtia sp., Caulacanthus okamurae, Ulva pertusa, and Gelidium amansii at Gujido and U. pertusa, Hildenbrandtia sp., Gelidium divaricatum at Daeyeonpyeongdo. The vertical distribution pattern of the seaweeds was G. divaricatum-U. pertusa, Hildenbrandtia sp.-U. pertusa, Hildenbrandtia sp., Ishige okamurae from upper to lower intertidal zone but seaweed zonations were not observed on the Gujido rocky shore. At both sites, coarsely-branched forms were the dominant functional group in species number and percent cover(among benthic algal species). The rocky shores of the two sites were dominated by crustose coralline and green algae, whose presence generally results in decreased seaweed biodiversity and community stability. Therefore, the shores of the Yeonpyeongdo islets are of considerable environmental concern and should be monitored for seaweed species composition and community structure.

A New Species of the Genus Iotrochota (Demospongiae: Poecilosclerida: Iotrochotidae) from Korea

  • Kim, Mi-Jeong;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • v.26 no.1
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    • pp.79-82
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    • 2010
  • new species Iotrochota rutzleri n. sp. (Demospongiae: Poecilosclerida: Iotrochotidae) was collected from intertidal zone, Sinyangri, Seongsanpo, Jejudo Island, Korea during 2008-2009. Iotrochota rutzleri n. sp. is similar to I. baculifera Ridley, 1884 in composition of spicules and skeletal structure. However, it is different in size of spicules, growth form and colour. All spicules of this new species are smaller than those of the latter.

A New Species of Genus Diplastrella (Demospongiae: Hadromerida: Spirastrellidae) from Korea

  • Kim, Mi-Jeong;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • v.25 no.1
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    • pp.61-64
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    • 2009
  • A new species Diplastrella yongmeoriensis n. sp. was collected from Jejudo Island, Korea in 2008. This new species is similar to D. bistellata (Schmidt, 1862) in growth form and skeletal structure but differs in the composition and size of spicules. The genus Diplastrella is reported for the first time in Korea.