• Title/Summary/Keyword: Disturbed area

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Comparison of Vegetation Structure and Environmental Factors between the Disturbed and Undisturbed Wetlands around the Littoral Zone of Namgang (남강의 연안대 습지에서 교란지와 비교란지의 식생구조와 환경요인의 비교)

  • Gang, Seon-Hee;Lee, Pal-Hong;Son, Sung-Gon;Kim, Cheol-Soo;Oh, Kyung-hwan
    • Journal of Wetlands Research
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    • v.3 no.1
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    • pp.1-17
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    • 2001
  • The flora, vegetation structure, distribution of the vascular plants, physico-chemical characteristics of sediment, and nutrient contents of palnts were investigated in the ten disturbed and undisturbed wetlands around the littoral zone of Namgang, Jinju-si, Gyongsangnam-do, Korea from August 7 to August 15 in 1999. 217 taxa of the vascular plants distributed into 2 formas, 26 varieties, 189 species belong to 142 genera under 52 families were sampled or recorded. Dominant species of the undisturbed and the disturbed area were Persicaria thunbergii and Ambrosia artemisiifolia var. elatior, of which importance values were 13.86, and 15.81, respectively. Among 26 species of the naturalized plants, importance value of Ambrosia artemisiifolia var. elatior was highest as 9.54. The ranges of species diversity indices (H') were 1.370~1.819, and highest in the site 1 of the undisturbed area. The ranges of eqitability (J') were 0.779~0.902, and highest in the site 8 of the disturbed area. The ranges of community similarity indices ($CC_s$) were 0.341~0.578 among the ten wetlands, and highest between site 1 and site 2 which were the undisturbed area. The ranges of sediment properties such as pH, conductivity, organic matter, total phosphorus, and total nitrogen were 5.17~7.35, $24.67{\sim}74.33{\mu}mhocm^{-1}$, 1.09~3.82%, 0.0008~0.0034 mg/100g, and 0.06~0.15%, respectively. Nutrient contents of plants such as total nitrogen and total phosphorus were 1.52~2.65% and $0.010{\sim}0.039mg100g^{-1}$, respectively. It was recommended that the establishment of the conservation area was necessary to ensure the habitat for wild life and to maintain the diversity of the vascular hydrophytes and hygrophytes.

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Laminar Flow Inhibits ER Stress-Induced Endothelial Apoptosis through PI3K/Akt-Dependent Signaling Pathway

  • Kim, Suji;Woo, Chang-Hoon
    • Molecules and Cells
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    • v.41 no.11
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    • pp.964-970
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    • 2018
  • Atherosclerosis preferentially involves in prone area of low and disturbed blood flow while steady and high levels of laminar blood flow are relatively protected from atherosclerosis. Disturbed flow induces endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). ER stress is caused under stress that disturbs the processing and folding of proteins resulting in the accumulation of misfolded proteins in the ER and activation of the UPR. Prolonged or severe UPR leads to activate apoptotic signaling. Recent studies have indicated that disturbed flow significantly up-regulated $p-ATF6{\alpha}$, $p-IRE1{\alpha}$, and its target spliced XBP-1. However, the role of laminar flow in ER stress-mediated endothelial apoptosis has not been reported yet. The present study thus investigated the role of laminar flow in ER stress-dependent endothelial cell death. The results demonstrated that laminar flow protects ER stress-induced cleavage forms of PARP-1 and caspase-3. Also, laminar flow inhibits ER stress-induced $p-eIF2{\alpha}$, ATF4, CHOP, spliced XBP-1, ATF6 and JNK pathway; these effects are abrogated by pharmacological inhibition of PI3K with wortmannin. Finally, nitric oxide affects thapsigargin-induced cell death in response to laminar flow but not UPR. Taken together, these findings indicate that laminar flow inhibits UPR and ER stress-induced endothelial cell death via PI3K/Akt pathway.

Invasive alien plant Characteristics and Management Measures in Mt. Inwang, Seoul (서울 인왕산의 침입외래식물 특성 및 관리방안)

  • Cha, Doo-Won;Ban, Su-Hong;Oh, Choong-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.6
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    • pp.89-96
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    • 2019
  • This study was carried out for management of the invasive alien plants in Mt. Inwang located in central Seoul. The invasive alien plants are 11 families, 34 genera, 30 taxa, and they are 10.8% of the total vascular plants(314 taxa). The ecosystem disturbed plants designated by the Korea environment ministry are 6 taxa : Rumex acetosella, Lactuca scariola, Ambrosia trifida var. trifida, Ambrosia artemisiifolia, Aster pilosus and Eupatorium rugosum. In the life-form, herbaceous perennials are 13 taxa(35.3%). In the continent of origin, the species from America are 20 taxa(58.8%). In the introduction time, the species of third period are 14 taxa(41.2%). In the diffusion grade, 5 grade species are 14 taxa(41.2%) and they are wide spread species. Mt. Inwang was designated as ecological scenery conservation area of Seoul in 2007. But Mt. Inwang is in high danger by the spread of invasive alien plants and ecosystem disturbed plants, due to artificial factors such as development pressure and the occurrence of byway trail. Therefore, Mt. Inwang needs systematic management of invasive alien plants and monitoring of long-term changes.

Development of a Kinematic Wave Model to Route Overland Flow in Vegetated Area (II) -Runoff Plot Experiments and Model Application- (초지의 지표면 흐름을 추적하기 위한 Kinematic Wave Model의 개발(II) - 포장실험과 모형의 응용 -)

  • ;W.L.Magette
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.3
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    • pp.74-80
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    • 1993
  • Runoff simulation tests to investigate the flow mechanics of nonsuomerged overland flow in a natural grass intervening land system were condueted and a modified kinematic wave overland runoff model developed by Choi et al. (1993) was verified. Nonhomogeneity and heterogeneity of the soil, slope, local topography, infiltration, grass density, and the density and activity of the soil microhes and wild animals were the major factors affecting the flow. Streamlines were disturbed by grass stems and small concentrated flows due to the disturbed streamlines and local topography were observed a lot. Relatively larger concentrated flows were observed where bundles of grass were dominant than where individual grasses were growing. Predicted hydrographs were agreed verv well with measured hydrographs. Since the modified model considers grass density in computing flow depth and hydraulic radius, it can be better than existing kinematic wave model if it were used to route nonpoint source pollutant attenuation processes in many grass intervening land systems.

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A case study of large-scale slope failure in Granite - Andesite contact area (화강암-안산암 접촉부 대규모 사면의 붕괴 사례 연구)

  • 이수곤;양홍석;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.503-508
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    • 2003
  • In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

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Characteristics of Clay Minerals in Sihwa Area (시화지구 연약점토의 광물학적 특성)

  • 김낙경;박종식;김유신
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.773-780
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    • 2003
  • The characteristics of soft clays is very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the disturbed clay samples obtained from Sihwa area. This study included X-Ray Diffraction Analysis, X-Ray Fluorescence Spectrometer Analysis, Scanning Electron Microscopy Analysis and Energy Dispersive X-Ray Spectrometer Analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated.

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A Study on the Flora and its Introduced Disturbing Plants in Damyang Area of Mudeungsan National Park, Korea (무등산국립공원 담양 지구의 식물상과 생태계교란 식물에 관한 연구)

  • Lee, Jong-Won;Lee, Suhong;Kang, Shin-Ho
    • Korean Journal of Plant Resources
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    • v.34 no.1
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    • pp.103-113
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    • 2021
  • This study was investigated to find out the distribution of flora and remarkable plants and factors and management measures for influx of wild disturbed plants in the Damyang area of Mudeungsan National Park. The field survey was carried out 8 times from May 2019 to October 2020. First of all, in the Damyang area of Mudeungsan National Park, a total of 603 taxa in 107 families, 349 genera, 531 species, 57 varieties, 5 subspecies and 10 forms. This result was found to be about 12.33% of the total 4,881 taxa of vascular plants in Korea. In addition, Rare plants were classified as 15 taxa. Floristic special and Korean endemic plants were identified as 85 taxa and 13 taxa, respectively. Lastly, the naturalized plants that appeared in the Damyang area of Mudeungsan National Park were observed in 45 taxa with 45 species of 16 families and 36 genera. Moreover the naturalization rate was 7.46% and the urbanization index was calculated to be 14.01%. The wild disturbed plants were found in a total of 4 taxa. Especially, a sheep sorrel(Rumex acetosella) was focused on managing for physica and biological control at Sinseondae Eoksaepyungjeon.

Plant Settlement Patterns and Their Effects on Breeding Sites of Little Terns (Sterna albifrons) on Sand Bars on Ganwol Lake

  • Nam, Jong-Min;Yoon, Ji-Hyun;Kim, Heung-Tae;Kim, Jae-Geun
    • Journal of Ecology and Environment
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    • v.31 no.1
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    • pp.37-43
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    • 2008
  • We analyzed soil characteristics, soil seed banks, and plant communities in a small islet in Ganwol Lake from May 2005 to August 2006 to examine the forces driving plant settlement on sand bars and the effects of plant settlement patterns on nesting sites of little terns (Sterna albifrons). The soil nutrients contents in a site where the feces of wintering birds accumulate (N: 15.4 mg/kg, P: 10.5 mg/kg, LOI: 0.51 %, pH: 6.8) and a site where organic sediments accumulate (N: 20.7 mg/kg, P: 16.4 mg/kg, LOI: 0.40%, pH: 6.6) were much higher those of a control site which was not affected by bird feces and organic sediments (N: 4.1 mg/kg, P: 5.4 mg/kg, LOI: 0.41%, pH: 6.7). However, a seed bank was formed only on the site with accumulated organic sediments. Plant settlement was accelerated by feces from wintering birds and organic sediment accumulation on sand bars in Ganwol Lake. The percentage of area disturbed by human activities increased from 0.2% in May 2005 to 13.9% in August 2006, and the percentage of annual communities increased from 27.5% to 43.3%, but the percentage of open area decreased from 55.2% to 28.0% from May 2005 to August 2006. These increases in disturbed area and annual communities decreased the open area for breeding of little terns. The enlargement of P. communis and T. angustata communities was suppressed by irregular flooding. These results provide useful information for the management of little tern breeding sites for conservation purposes.

Palynological study of the alluvial vally plain deposits from the miruksa site, iksan-gun, korean (益山郡 彌勒寺址의 堆積層에 對한 花紛分析的 硏究)

  • Choi, Kee-Ryong
    • The Korean Journal of Ecology
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    • v.15 no.1
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    • pp.59-65
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    • 1992
  • Pollen analysis to clear vegetational history of korea was carried out on the deposite taken from the pit of the miruksa site, south-western korea(36o00'18'N, 127o1'12'E, 10m in alt.). This area has been known as the cool temperate zone(southern zone) according to yim and kira(1975). But, now we can not found the original vegetation because the area has been disturbed severely and almost area changed to cultivated land.the area is one of the most developd area in early agricultural stage of korea. By the pollen diagram, three local pollen zones are distinguished in this site, bottom to surface, as following. is-Ⅰ :pinus-quercus zone (140∼120 cm, sample 1 and 2) is-Ⅱ :ulmus+zelkova zone(120∼84 cm, sample 3∼6) is-Ⅲ :pinus zone(84∼0 cm, sample 7 ∼13) is-Ⅰ is characterized by high values in frequences of pinus, the temperate conifer and quercus the cool temperate oak, and is-Ⅱ zone by the decrease of quercus and increase of ulmus and increase of ulman+zelkova as ravine forest elements, isⅢ zone is characterized by pinus, especially, based on data of sample no.9.

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