• 제목/요약/키워드: whole communities

검색결과 152건 처리시간 0.027초

남한과 일본의 임연군란 비교 연구 (A Comparative Study on Mantle Communities in South Korea and Japan)

  • 정용규;김종원
    • The Korean Journal of Ecology
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    • 제21권1호
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    • pp.81-88
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    • 1998
  • A comparative analysis on mantle communities in South Korea and Japan was carried out. The study was accomplished by using syntaxa and hierarchical system of mantle communities in South Korea and Japan through Zurich-Montpellier School's method, and also achieved comparison on syntaxonomy, synecology, syndynamics and syngeography between two countries. Mantle communities in South Korea and Japan were defined to the Rosetea multilorae representing mantle vegetation in Northeast Asia. Mantle communities in Japan showed much diverse than those in South Korea. Mantle communities in South Korea and Japan considerably corresponded between the two. Results of the current study will make possible to accumulate qualitative $\bullet$quantitative informations on mantle communities in Northeast Asia. And the subsidiary knowledge from this study will provide practical data on comparative analysis about whole mantle communities in Northeast Asia.

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Effects of whole-plant corn and hairy vetch (Vicia villosa Roth) mixture on silage quality and microbial communities

  • Yaqian Zong;Kai Zhou;Xinhui Duan;Bo Han;Hua Jiang;Chenggang He
    • Animal Bioscience
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    • 제36권12호
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    • pp.1842-1852
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    • 2023
  • Objective: Hairy vetch is considered to improve the nutritional value of corn because of its high protein and mineral levels. To better understand the mechanism underlying hairy vetch regulated whole-plant corn silage fermentation, this experiment investigated the fermentation quality and bacterial community of whole-plant corn and hairy vetch mixture. Methods: Whole-plant corn and hairy vetch were mixed at ratios of 10:0 (Mix 10:0), 8:2 (Mix 8:2), 6:4 (Mix 6:4), 4:6 (Mix 4:6), 2:8 (Mix 2:8), and 0:10 (Mix 0:10) on a fresh weight basis. After ensiling 60 days, samples were collected to examine the fermentation dynamics, ensiling characteristics, and bacterial communities. Results: Mix 0:10, Mix 2:8, and Mix 4:6 showed poor fermentation characteristics. Mix 8:2 and Mix 6:4 silages showed high quality, based on the low pH, acetic acid, and ammonia nitrogen levels and the high lactic acid, crude protein, and crude fat contents. The bacterial diversity was affected by the mixing ratio of the two forage species. The genus Lactobacillus dominated the bacterial community in Mix 10:0 silage, whereas with the addition of hairy vetch, the relative abundance of unclassified-Enterobacter increased from 7.67% to 41.84%, and the abundance of Lactobacillus decreased from 50.66% to 13.76%. Conclusion: The silage quality of whole-plant corn can be improved with inclusion levels of hairy vetch from 20% to 40%.

Diversity of bacterial community during ensiling and subsequent exposure to air in whole-plant maize silage

  • Hu, Zongfu;Chang, Jie;Yu, Jianhua;Li, Shuguo;Niu, Huaxin
    • Asian-Australasian Journal of Animal Sciences
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    • 제31권9호
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    • pp.1464-1473
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    • 2018
  • Objective: To describe in-depth sequencing, the bacterial community diversity and its succession during ensiling of whole-plant maize and subsequent exposure to air. Methods: The microbial community dynamics of fermented whole-plant maize for 60 days (sampled on day 5, 10, 20, 40, 60) and subsequent aerobic exposure (sampled on day 63 after exposure to air for 3 days) were explored using Illumina Miseq sequence platform. Results: A total of 227,220 effective reads were obtained. At the genus level, there were 12 genera with relative abundance >1%, Lactobacillus, Klebsiella, Sporolactobacillus, Norank-c-cyanobacteria, Pantoea, Pediococcus, Rahnella, Sphingomonas, Serratia, Chryseobacterium, Sphingobacterium, and Lactococcus. Lactobacillus consistently dominated the bacterial communities with relative abundance from 49.56% to 64.17% during the ensiling process. Klebsiella was also an important succession bacterium with a decrease tendency from 15.20% to 6.41% during the ensiling process. The genus Sporolactobacillus appeared in late-ensiling stages with 7.70% abundance on day 40 and 5.32% on day 60. After aerobic exposure, the Lactobacillus decreased its abundance from 63.2% on day 60 to 45.03% on d 63, and Klebsiella from 5.51% to 5.64%, while Sporolactobacillus greatly increased its abundance to 28.15%. These bacterial genera belong to 5 phyla: Firmicutes (relative abundance: 56.38% to 78.43%) was dominant, others were Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria. The bacterial communities clearly clustered into early-ensiling (d 5), medium-ensiling (d 10, d 20), late-ensiling (d 40, d 60), and aerobic exposure (d 63) clusters, with early- and late-ensiling communities more like each other than to the aerobic exposure communities. Conclusion: High-throughput sequencing based on 16S rRNA genes proved to be a useful method to explore bacterial communities of silage. The results indicated that the bacterial communities varied during fermentation and more dramatically during aerobic exposure. The study is valuable for understanding the mechanism of population change and the relationship between bacteria and ensilage characteristics.

덕유산 국립공원 삼림식생의 종 다양성 (Species Diversity of Forest Vegetation in Togyusan National Park)

  • Kim, Chang-Hwan;Bong-Seop Kil
    • The Korean Journal of Ecology
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    • 제19권3호
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    • pp.223-230
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    • 1996
  • Five measurements of species diversity (richness index, diversity index, evenness index, dominance index and species sequences-importance curve) and their relationships with sltitude, tree age and community type were studied in $T\v{o}gyusan$ National Park, Korea. Altitude and tree age were the major variables explaining the differences of species diversity in the whole forest. Species richness index, diversity index and evenness index of Quercus mongolica and Pinus densiflora communities were lower than those of Carpinus laxiflora, Q. serrata, Fraxinus mandshurica, Q. mongolica - P. densiflora communities than that in the other communities. The species sequence-importance curve of the forest communities in $T\v{o}gyusan$ coincided with the ideal curve calculated by the lognormal-distribution theory.

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자기부상열차 도입의 교통경제학적 평가방법 연구 (Transportation Economic Analysis Method for a Maglav System)

  • 김현웅
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.1276-1280
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    • 2005
  • The Maglav system project affects communities and are usually funded by public agencies. Evaluation of this project that considerably impact whole communities requires public involvement. This specific requirement of transportation projects determines the method of their evaluation as the impacts are estimated from the transportation economic point of view. Especially evaluation criteria must reflect the needs of the interested parties and should consider all foreseeable benefits and losses caused by the Maglav project. To select evaluation criteria and evaluation method may help a decision--maker in making a best selection for a Maglav project.

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괴산군 일대의 식생 및 식생기반에 관한 연구 (A Study of the Vegetation and Vegetation Base around the Goesan Gun)

  • 윤재로;민현기;주진희;윤용한
    • 한국환경과학회지
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    • 제19권5호
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    • pp.533-541
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    • 2010
  • The purpose of this study is to grasp what characterizes the vegetation base of the natural forest as a latent vegetation in the middle region of Korea and thus to offer basic data when improving the vegetation base in the middle region being built or to be built in the future. The findings of this soil section survey show the following: The soil is brown to red color soil group on the whole. In addition, the soil's physical features like soil hardness are rated as high level, which results from the fact that the forest soil exits in its natural form under less influence of stamping. The pH of soil shows a weak acidity, like Korean normal soil. Specific electrical conductance is also rated as middle to high level in accordance with the standards of landscape architecture. The Salix koreensis community and the Pinus rigida community are different from other communities in terms of total nitrogen, available phosphate and exchangeable $K^+$ content. Specifically, the two communities are opposed to each other in terms of total nitrogen and available phosphate, while being similar to each other in terms of available phosphate and exchangeable $K^+$ content. This seems to result from the fact that they are located near each other. In addition, the two communities are characterized by the fact that they are distributed at the altitude mean relatively lowest and in the valley. To sum up, the forest soil around Goesan Gun is of middle level on the whole according to the landscape standards, when judging it in terms of vegetation base. Accordingly, it seems that the construction of the vegetation base around Goesan Gun will not require large investment expenses for soil improvement. Also, it seems that the spatial scope of research is needed to expand the basic data on the construction of the vegetation base for the whole middle region of Korea.

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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    • 제32권5호
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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.

Recovery of aquatic insect communities after a catastrophic flood in a Korean stream

  • Lee, Hwang-Goo;Bae, Yeon-Jae
    • Animal cells and systems
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    • 제15권2호
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    • pp.169-177
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    • 2011
  • In August 2002, a heavy rainfall (445 mm in total for 5 consecutive days) resulted in a catastrophic flood, and it completely washed away the benthic fauna from the mainstream channel of the Gapyeong stream, a typical mid-sized stream in the central Korean peninsula. This study was to investigate the recovery patterns of aquatic insect communities that were damaged by the flood. Aquatic insects were sampled quantitatively using a Surber sampler ($50{\times}50$ cm, 1 riffle and 1 pool/run habitats per site) from three sites (4th-6th order) of the Gapyeong stream prior to 2000 and seasonally after the flood event from 2003 to 2006. Before the flood in the reference year (2000), a total of 77 species of aquatic insects were collected, whereas after the flood 47 species (2003), 51 species (2004), 64 species (2005) and 55 species (2006) were collected from the whole sampling sites. The aquatic insect density decreased to 26.85% (2003), 90.25% (2004), 52.53% (2005) and 54.95% (2006) of that recorded in the reference year. Although approximately 70% of the aquatic insect fauna has recovered since the flood event, the species composition in the most recent year differed substantially (similarity ca. 50%). On the other hand, the compositions of functional groups have not significantly changed. Aquatic insect communities at the riffle sites were affected more profoundly than those at the pool/run sites. The aquatic insect communities at the upstream site recovered more rapidly than those at the downstream sites.

사회적 지속가능성을 위한 고령친화 환경 분야 최근 경향연구 -노인환경전문학술대회 발표물을 중심으로- (Analysis of Major Trends appeared in recent Aging Friendly Environment for Social Sustainability -with Reference to Presentations of the Conference on Environments for Elderly-)

  • 안소미;이연숙
    • KIEAE Journal
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    • 제10권3호
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    • pp.117-125
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    • 2010
  • Entering into the 21th century, the whole world is facing the various problems such as environmental disruption, resource exhaustion, and social isolation due to the consequences of population growth and economic development. Especially, as the world population is aging, the solutions for these problems are being suggested with a new paradigm of environmental design for sustainable society providing more affluent and safer life for them. Aging societies are experiencing the difficulty in pursuing persistent vitality of life when aged population is socially excluded, and communities are stagnant due to the decrease of economic activities. In other words, those factors are causing the problems of social sustainability associated with the vital duration of local society and communities. In order to develop successful environment for aging society, it is necessary for us to precisely review how advanced countries are changing their directions. Therefore, the purpose of this study is to examine current trends of the aging friendly environment and find out the measures to promote social sustainability under the crisis of aging society. For this purpose, using qualitative methods, this study analyzed the contents presented at a professional conference , that showed current trends clearly, into three dimensions of social sustainability; the social integration of senior living communities with local society, the vitality of the communities, and the invigoration of individual senior lives. As a result, this study found that the measures that attempt to enhance the social sustainability of aging population can be also used to invigorate the communities.

Anonymous Participation and Collaboration Efficiency in Online Communities

  • Hong Joo Lee;Jong Woo Kim;Hyun Jung Park;Sung Joo Park
    • Asia pacific journal of information systems
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    • 제30권3호
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    • pp.497-512
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    • 2020
  • Anonymity is one of the key factors that influence communication and the work behaviours of people. It is even more evident in an online community where the role of anonymity can be akin to a double-edged sword: it can increase participation while at the same time having detrimental effects due to irresponsible and disruptive behaviour. Most studies on anonymous participation in groups or communities have reported this ambivalent view of anonymity: positive or negative. Furthermore, the effects of anonymous participation may be different in a dynamic sense because the task characteristics of participation can vary across time. In this study, we hypothesise that the effects of anonymity in online collaboration differ across the stages of collaboration. We analysed 2,978 featured articles on the English-language Wikipedia website and investigated the contributions of anonymous participants. While the contributions of anonymous participants were negative to collaboration efficiency as a whole, the negative effect of anonymous participants was stronger in the earlier stage than the later stage of collaboration. These findings indicate that the effect of anonymity has two sides in terms of collaboration efficiency in the same collaborative environment.