• Title/Summary/Keyword: Rare sub-community

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Responses of Soil Rare and Abundant Sub-Communities and Physicochemical Properties after Application of Different Chinese Herb Residue Soil Amendments

  • Chang, Fan;Jia, Fengan;Guan, Min;Jia, Qingan;Sun, Yan;Li, Zhi
    • Journal of Microbiology and Biotechnology
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    • v.32 no.5
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    • pp.564-574
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    • 2022
  • Microbial diversity in the soil is responsive to changes in soil composition. However, the impact of soil amendments on the diversity and structure of rare and abundant sub-communities in agricultural systems is poorly understood. We investigated the effects of different Chinese herb residue (CHR) soil amendments and cropping systems on bacterial rare and abundant sub-communities. Our results showed that the bacterial diversity and structure of these sub-communities in soil had a specific distribution under the application of different soil amendments. The CHR soil amendments with high nitrogen and organic matter additives significantly increased the relative abundance and stability of rare taxa, which increased the structural and functional redundancy of soil bacterial communities. Rare and abundant sub-communities also showed different preferences in terms of bacterial community composition, as the former was enriched with Bacteroidetes while the latter had more Alphaproteobacteria and Betaproteobacteria. All applications of soil amendments significantly improved soil quality of newly created farmlands in whole maize cropping system. Rare sub-communitiy genera Niastella and Ohtaekwangia were enriched during the maize cropping process, and Nitrososphaera was enriched under the application of simple amendment group soil. Thus, Chinese medicine residue soil amendments with appropriate additives could affect soil rare and abundant sub-communities and enhance physicochemical properties. These findings suggest that applying soil composite amendments based on CHR in the field could improve soil microbial diversity, microbial redundancy, and soil fertility for sustainable agriculture on the Loess Plateau.

Chemical Water Quality and Fish Component Analyses in the Periods of Before- and After-the Weir Constructions in Yeongsan River

  • Kwak, Sang Do;Choi, Ji-Woong;An, Kwang-Guk
    • Journal of Ecology and Environment
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    • v.39 no.1
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    • pp.99-110
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    • 2016
  • The objective of this study was to analyze chemical water quality, ecological characteristics of fish compositions, and ecosystem health before- (Bwc; 2008-2009) and after-the weir construction (Awc; 2011-2012) at Juksan Weir and Seungchon Weir of Yeongsan River watershed. Suspended solids (SS) and chlorophyll-a (Chl-a) in Juksan Weir increased, whereas nutrients such as total nitrogen (TN) and total phosphorus (TP) decreased in the epilimnetic water. In Juksan and Seungchon weirs, fish species distribution analysis in the periods of Bwc and Awc showed that sensitive species were rare and tolerant species were dominant in the community. In the analysis of trophic guild, relative abundance of carnivore species are increased to 22% and 12%, respectively, after the constructions of Seungchon Weir and Juksan Weir. Mann-Whitney U-tests of nonparametric statistical analysis indicated that omnivore and carnivore species had significant differences (p < 0.05) between the Bwc and Awc. The massive population growth of an exotic species, Micropterus salmoides, was evident in Seungchon Weir to influence on the structures of fish communities. The model values of mean Index of Biological Integrity (IBI), based on fish assemblages, were < 15, which indicates "poor" condition in the river health, and the significant difference of IBI values was not found between the Bwc and Awc.

Numerical Study on the Characteristics of High PM2.5 Episodes in Anmyeondo Area in 2009 (2009년 안면도 지역 고농도 PM2.5 특성에 관한 수치 연구)

  • Jeon, Won-Bae;Lee, Hwa Woon;Lee, Soon-Hwan;Park, Jae-Hyeong;Kim, Hyun-Goo
    • Journal of Environmental Science International
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    • v.23 no.2
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    • pp.249-259
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    • 2014
  • This paper investigates the characteristics of high $PM_{2.5}$ episodes occurred at Anmyeondo area in spring time, 2009. The monthly mean $PM_{2.5}$ concentration during April was the highest in the year and especially, high levels of $PM_{2.5}$ exceeding standard regulation level were sustained consecutively during 5 to 13 April. To analyze more detailed $PM_{2.5}$ characteristics, numerical simulations were carried out using CMAQ(Community Multi-scale Air Quality) with IPR(Integrated Process Rate) and DDM-3D(Decoupled Direct Method). $PM_{2.5}$ level was lower in daytime than that in nighttime due to vigorous vertical mixing during daytime. The chemical composition was showed that ratio of primary ion components such as sulfate($SO_4{^{2-}}$), nitrate($NO_3{^-}$) and ammonium($NH_4{^+}$) were nearly half of total amount of $PM_{2.5}$. Aerosol and transport process dominantly contributed to $PM_{2.5}$ concentration in Anmyeondo area and contribution rate of local emissions was nearly zero since Anmyeondo area has rare anthropogenic PM emission sources. DDM-3D analysis result showed that $PM_{2.5}$ in Anmyeondo area was influenced by emissions from Shanghai and Shandong region of China.

Ecological Characteristics and Distribution of Native Trillium tschonoskii in Ulleung Island (울릉도 자생 큰연령초의 분포와 자생지의 생태적 특성)

  • Ahn, Young-Hee;Lee, Sung-Jae;Lee, Sang-Hyun
    • Korean Journal of Pharmacognosy
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    • v.38 no.2 s.149
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    • pp.157-163
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    • 2007
  • Trillium tschonoskii Maxim. is a kind of 64 endangered plant species designated by the Ministry of Environment in Korea. It is very a rare native plant throughout the country. Therefore, this study was conducted to investigate the native T. tschonoskii in Ulleung Island for their distribution and ecological characteristics. They were mostly distributed valley, mid-slope of the mountain from 186 to 458 m altitude. They had a little low light conditions as they faced west, north west, south west, south-south west, north-north east and east-east north. They were provided with slightly humid condition. Aerial humidities of these quadrates were variable as 21.5-71%. They were located on the variable slopes of 5 to 43 degrees. Soil humidity was slightly dry. Native sites were semi-shaded because tree layer such as Tilia insularis, Zelkova serrata, okamotoanum etc.and sub-tall tree layer such as Ligustrum foliosum, Comellia japonica, Tilia insularis, Callicarpa japonica and so on were grown near by. Woody plants such as A. Okamotoanum, Sorbus commixta, Fagus japonica var. multinervis etc. were frequently observed. These environmental conditions were suitable that T. tschonoskii grows up naturally because of high Percentage as 52.78% of blooming individuals in this study. These native sites were classified with three communities, T. tschonoskii-Majanthemum dilatatum community, T. tschonoskii-Anthriscus sylvestris community and T. tschonoskii-Hepatica maxima community in accordance with altitude and aerial humidity. The best way ffr the preservation of T. tschonoskii habitats and maintainance of its recent population is maintained in recent environmental condition and ecological condition without any management by human-being.

A Study on the Union Social Responsibility(USR) focused on LG Electronics Union (노조의 사회적 책임에 관한 연구 -LG전자 노동조합 사례를 중심으로-)

  • Kim, Sung-Gun;Kim, Joong-Wha
    • Journal of Digital Convergence
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    • v.12 no.2
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    • pp.193-202
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    • 2014
  • According to change of business environment, the company has required not only profit but also social responsibility for profitable growth. However, these changes are not only applies to the company. Company's internal stakeholders and social systems sub-elements of the union was forced to respond to these changes, too. However, research has not focused yet USR until now, It's very rare USR and introduction of USR and Case of USR. But The union must meet a the stakeholders such as nonunionist, county, as well as union members. This study looked at the USR Case of LG Electronics Union which is a leader in this filed. LG Electronics Union had accepted the USR in 2010, LG Electronics Union led innovation and change of labor movement and pushed ahead with USR such as service to community and vulnerable, refrain from strike, environmental protection. and LG Electronics Union spread the USR to overseas and domestic. Through the LG Electronics Union's USR Case, this study seek the new labor movement.

Biodiversity Conservation & World Natural Heritage in Bangladesh (방글라데시의 생물다양성 보전 및 세계자연유산)

  • Nayna, Omme Kulsum;Lee, Sang Don
    • Journal of Environmental Impact Assessment
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    • v.26 no.5
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    • pp.376-384
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    • 2017
  • Bangladesh is a South Asian country with subtropical monsoonal climate between the intersection of the Indo-Himalayan and Indo-Chinese sub-regions, is known as biodiversity hotspot of the Asian region. The country has different types of forest like deciduous forest, evergreen forest, mixed forest, haor (wetlands) and mangrove forest. The natural beauty of the country is increased with the presence of so many rivers, longest sea beach of the world, green plants, critical hilly regions and green agricultural forest widely spread here and there. Sundarbans is the world largest mangrove forest and world natural heritage site declared by UNESCO in 1999 situated in Bangladesh and India. About 62 percent of this mangrove forest is situated in Bangladesh and there are so many plants and animals are found in this forest. To meet the increasing demand of the large population most of the natural ecosystem is now altered, deforestation rate is increased, natural habitat of the species is disturbed. Due to the imbalance of the climate and natural system many of the rare species of the world found this region is now endangered and some of the species are extinct. Directly or indirectly they are benefited from natural resources. At present time community, based ecotourism is also an important source of income for rural poor peoples. To protect the natural resources the government is now developed so many conservation acts and policy as well NGOs are also doing work for the conservation of ecosystem and biodiversity. At present transboundary pollutants and so many natural disasters also destruct the natural resources of Bangladesh.