• 농촌계획
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• 제20권1호
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• pp.115-125
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• 2014

Rural villages have many problems such as the collapse of rural village communities with continued over-depopulation and aging, reduced functions of towns and villages, deteriorated services with changes in the structure of settlement class and decreased use of the facilities. they also have difficulties in maintenance in spite of the increase of the roles of rural village community facilities. Various plans for the utilization of community facilities to promote the vitality of rural villages and the revitalization of communities have been needed. Thus, this study aimed to offer basic data to seek for future plans to utilize community facilities and reconstruct communities through an analysis of the current uses of energy and community facilities in rural villages. The results indicated that the consumption of petroleum was highest in mountain villages at an average of 187,475 won/month($137{\ell}$), followed by fishing villages at an average of 144,142 won/month($104{\ell}$) and rural villages at an average of 126,070 won/month($93{\ell}$). The rate of utilization of community facilities was reversely highest in rural villages at 84.3%, followed by fishing villages at 61.1% and mountain villages at 40.7%. This research also found that households saved energy when they used community facilities and areas with a high rate of utilization of community facilities at a lower average temperature in winter. It saved approximately 33% energy compared to other areas. Finally, efficient and economical methods for community facilities in villages to be newly developed and the remodeling of existing facilities should been needed in the future to contribute to reconstructing rural village communities that face a crisis of maintenance or abolition.

• The Plant Pathology Journal
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• 제39권2호
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• pp.207-219
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• 2023

Soft rot is a widespread, catastrophic disease caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) that severely damages the production of Amorphophallus spp. This study evaluated the rhizosphere bacterial and fungal communities in Pcc-infected and uninfected plants of two species of Amorphophallus, A. muelleri and A. konjac. Principal component analysis showed that the samples formed different clusters according to the Pcc infection status, indicating that Pcc infection can cause a large number of changes in the bacterial and fungal communities in the Amorphophallus spp. rhizosphere soil. However, the response mechanisms of A. muelleri and A. konjac are different. There was little difference in the overall microbial species composition among the four treatments, but the relative abundances of core microbiome members were significantly different. The relative abundances of Actinobacteria, Chloroflexi, Acidobacteria, Firmicutes, Bacillus, and Lysobacter were lower in infected A. konjac plants than in healthy plants; in contrast, those of infected A. muelleri plants were higher than those in healthy plants. For fungi, the relative abundances of Ascomycota and Fusarium in the rhizosphere of infected A. konjac plants were significantly higher than those of healthy plants, but those of infected A. muelleri plants were lower than those of healthy plants. The relative abundance of beneficial Penicillium fungi was lower in infected A. konjac plants than in healthy plants, and that of infected A. muelleri plants was higher than that of healthy plants. These findings can provide theoretical references for further functional research and utilization of Amorphophallus spp. rhizosphere microbial communities in the future.

• Journal of Ecology and Environment
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• 제37권1호
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• pp.1-11
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• 2014

To understand the effects of fluctuations in dam discharge due to river environments and phytoplankton communities, we monitored such environments and phytoplankton communities biweekly, from February 2001 to February 2002 and from February 2004 to February 2005, in the lower Han River (LHR), South Korea. The phytoplankton abundance during the dry season was approximately two times higher than that during the rainy season. In particular, fluctuations in diatom assemblages, which constituted over 70% of the total phytoplankton abundance, were affected severely by the changes in the discharge. When a large quantity of water in a dam was discharged into the LHR, the conductivity and the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved inorganic phosphorus (DIP) decreased rapidly, whereas the concentrations of suspended solids (SS), dissolved inorganic nitrogen (DIN), and dissolved silica (DSi) increased immediately. Time-delayed relationship also revealed that the dam discharge had an immediately significant negative relationship with phytoplankton abundance. On the whole, fluctuations in phytoplankton communities in the LHR were influenced much more by hydrodynamics such as dam discharge than by the availability of nutrients. Thus, the variability in these concentrations usually parallels the strength of river flow that is associated with summer rainfall, with higher values during periods of high river discharge.

• The Plant Pathology Journal
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• 제37권6호
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• pp.662-672
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• 2021

Plant growth-promoting bacteria improve plant growth under abiotic stress conditions. However, their effects on microbial succession in the rhizosphere are poorly understood. In this study, the inoculants of Bacillus mesonae strain H20-5 were administered to tomato plants grown in soils with different salinity levels (EC of 2, 4, and 6 dS/m). The bacterial communities in the bulk and rhizosphere soils were examined 14 days after H20-5 treatment using Illumina MiSeq sequencing of the bacterial 16S rRNA gene. Although the abundance of H20-5 rapidly decreased in the bulk and rhizosphere soils, a shift in the bacterial community was observed following H20-5 treatment. The variation in bacterial communities due to H20-5 treatment was higher in the rhizosphere than in the bulk soils. Additionally, the bacterial species richness and diversity were greater in the H20-5 treated rhizosphere than in the control. The composition and structure of the bacterial communities varied with soil salinity levels, and those in the H20-5 treated rhizosphere soil were clustered. The members of Actinobacteria genera, including Kineosporia, Virgisporangium, Actinoplanes, Gaiella, Blastococcus, and Solirubrobacter, were enriched in the H20-5 treated rhizosphere soils. The microbial co-occurrence network of the bacterial community in the H20-5 treated rhizosphere soils had more modules and keystone taxa compared to the control. These findings revealed that the strain H20-5 induced systemic tolerance in tomato plants and influenced the diversity, composition, structure, and network of bacterial communities. The bacterial community in the H20-5 treated rhizosphere soils also appeared to be relatively stable to soil salinity changes.

• 환경생물
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• 제33권4호
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• pp.403-411
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• 2015

본 연구는 외부 해수가 계속적으로 유입되는 개방형 인공생태계와 해수의 유입이 없는 폐쇄형 인공생태계에서 미소생태계의 변화를 파악하고자 실험실 내에서 100 L 크기의 인공해양소형생태계 연구를 수행하였다. 수온은 폐쇄형 및 개방형 인공생태계에서 큰 차이가 없었다. 염분은 폐쇄형 생태계에서 수체의 증발에 따라 증가를 보였고 용존산소 및 용존무기질소 농도는 폐쇄형에서 감소하는 반면, 개방형에서는 초기농도와 큰 차이를 보이지 않았다. 용존무기인 및 용존규소는 두 시스템에서 차이가 없었다. 식물플랑크톤은 폐쇄형에서 감소를 하였던 반면, 개방형에서는 증가 양상을 보였으나 Autotrophic nanoflagellates는 식물플랑크톤 개체수의 변동과 반대되는 양상을 보였다. 타가영양세균은 폐쇄형에서 증가하는 양상을 보였고, 이와 함께 heterotrophic nanoflagellates 및 섬모충이 시간차를 두어 증가하는 양상을 보였다. 그러나, 개방형 인공생태계에서는 특이한 변화를 나타내지 않았다. 결론적으로, 폐쇄형 인공생태계와 개방형 인공생태계에서 미소생물상 및 환경요인들의 변화의 연구는 향후 연구자들이 인공생태계 연구에 있어서 기초자료로 활용할 수 있을 것으로 기대하며, 신뢰성 있는 인공생태계 연구를 수행할 수 있을 것으로 판단된다.

• Ocean and Polar Research
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• 제29권4호
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• pp.327-337
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• 2007

Plankton communities have close relationships with environmental changes in water columns. Thus, the use of plankton as a biological tool for assessing the marine ecosystem health may be effective. Major issue regarding coastal pollution has been usually recognized as phytoplankton blooms or red tides caused by the eutrophication, an increase in concentration of inorganic nutrients such as nitrogen and phosphorus. However, in order to understand the effects of the overall pollution on marine ecosystem, the organic pollutants as well as the inorganic nutrients should be also considered. For understanding the effects of the organic pollution, among the planktonic organisms, heterotrophic bacteria, heterotrophic flagellates and ciliates should be investigated. Generally, there are three approaches for assessing the marine ecosystem health using the plankton taxa or plankton communities. The first one is a community-based approach such as diversity index and chlorophyll a concentration which are common in analysis of the plankton communities. The second is an indiviual-based approach which is to monitor the pollution indicative species. This approach needs one's ability to identify the plankton to species level. The last approach is a bioassay of toxicity, which can be applied to the plankton. A pilot study in Masan Bay was conducted to assess the effects of the inorganic and organic pollution. In this article, a new approach using plankton communities was tentatively presented as a biological tool for assessing the ecosystem health of Masan Bay.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제4권2호
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• pp.86-94
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• 2023

Climate change is more rapid in the Arctic than elsewhere in the world, and increased precipitation and warming are expected cause changes in biogeochemical processes due to altered microbial communities and activities. It is crucial to investigate microbial responses to climate change to understand changes in carbon and nitrogen dynamics. We investigated the effects of increased temperature and precipitation on microbial biomass and community structure in dry tundra using two depths of soil samples (organic and mineral layers) under four treatments (control, warming, increased precipitation, and warming with increased precipitation) during the growing season (June-September) in Cambridge Bay, Canada (69°N, 105°W). A phospholipid fatty acid (PLFA) analysis method was applied to detect active microorganisms and distinguish major functional groups (e.g., fungi and bacteria) with different roles in organic matter decomposition. The soil layers featured different biomass and community structure; ratios of fungal/bacterial and gram-positive/-negative bacteria were higher in the mineral layer, possibly connected to low substrate quality. Increased temperature and precipitation had no effect in either layer, possibly due to the relatively short treatment period (seven years) or the ecosystem type. Mostly, sampling times did not affect PLFAs in the organic layer, but June mineral soil samples showed higher contents of total PLFAs and PLFA biomarkers for bacteria and fungi than those in other months. Despite the lack of response found in this investigation, long-term monitoring of these communities should be maintained because of the slow response times of vegetation and other parameters in high-Arctic ecosystems.

• 농촌계획
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• 제22권3호
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• pp.119-129
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• 2016

The aim of this study is to suggest the quantitative standard of a marginal village. For the purpose, the study selected 43 villages with the population of 50 or less, the classification of a marginal village in accordance with advanced research and 47 villages with the population over 50 in Buyeo-gun region. The common reason of occurrence of a marginal village suggested by advanced research is a characteristic of a village or decline and extinction of a village rather than a simple index of population or aging rate. Therefore, the study assumed that decline of functions of the village would be caused by decline a function of communities consisting of the villagers. The study then assumed that the relatively low or 0 number or rate of participants would result in community functions. The study conducted t-test on basis of population and aging rate and an analysis to find the range with relatively large differences in the number of communities, participants and the rate of the participants, etc. The result showed that the community function began to decline when the population was less than 60~70 and the aging rate over 75%~85%. As the decline of functions of communities began in population of 70, the critical point was met when the population was 40 or less. With population of 40 or less, the young and the old group communities became extinct or showed rapid decrease in the number of participants. The study assumed that decline of functions of a village, a reason of occurrence of a marginal village would be decline of functions of communities, but there was no further analysis on decline or extinction of a village with population of 40 or less. There shall be further studies about whether a village of population of 40 or less is led to decline of a function or extinction of village communities.

• 한국도서관정보학회지
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• 제49권1호
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• pp.233-265
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• 2018

본 연구는 국내 어린이도서관 문화프로그램의 사회적 효과를 측정하여 어린이도서관의 사회적 가치를 제시하였다. 이를 위해 초등학생 511명을 대상으로 설문조사를 실시하여 어린이도서관 문화프로그램의 사회적 효과를 측정하였다. 분석 결과 개인적 영역의 표현력/창의력, 자존감, 즐거움/기쁨/행복과 사회적 영역의 문화예술태도와 문화예술경험변화 및 사회적 상호작용으로 친구관계 증대, 지역커뮤니티 생성과 강화, 지역사회 소속감/공동체성, 지역사회참여 등의 효과가 있는 것으로 나타났다. 이를 근거로 어린이도서관은 어린이의 삶의 질을 향상하고, 사회적 상호작용 역량의 향상, 지역사회 공동체 유지 및 지역커뮤니티 생성과 강화, 지역애착과 지역 활동 참가에 영향을 미치는 중요한 사회자본으로 가치를 가진다고 볼 수 있다.

• 한국환경생태학회지
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• 제27권4호
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• pp.449-461
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• 2013

본 연구는 백두대간 향로봉에서 깃대배기봉 구간에 있는 신갈나무군락을 대상으로 2개의 권역(I, II)으로 나누어 고도에 따른 군락 특성을 살펴보았다. 조사는 신갈나무군락 총 63개를 대상으로 하였다. TWINSPAN에 의한 classification 분석 결과 총 5개 군락(A~E)으로 분류되었다. 군락의 지역적 분포는 A군락의 경우 해발고도 1,300m 이상의 태백산 일대에서(II권역) 주로 나타났으며 B, C군락은 해발고도 700~1,500m 사이의 설악산과 오대산 지역(I권역)에서 D, E군락은 1,100m 이하의 청옥산과 금대봉 지역(II권역)에 밀집해 있었으며 그 외 설악산과 오대산 지역(I권역)에서도 나타났다. 각 군락의 교목과 관목 개체수, 최대종다양도, 교목의 수고는 고도가 높아짐에 따라 차츰 낮아지는 특성을 보였다. 그리고 40년까지의 수목 생장량을 살펴본 결과 해발고도 1,100m 이하 지점까지는 특별한 경향을 보이지 않았지만 1,100m 이상에서는 수목 생장량이 급격히 낮아지는 특성을 보였다. 연구대상지에 출현한 수종들 간의 상관관계 분석 결과는 고도 1,000m 이상에서는 거제수나무와 신갈나무가 -0.53으로 음(-)의 상관관계를 보였으며 고도 1,000m 이하에서는 신갈나무와 산딸기가 0.59로 양(+)의 상관관계를 보였다. 결과를 종합해 볼 때 고도에 따른 환경 변화가 신갈나무군락의 종조성, 개체수, 생장량 등에 영향을 미치는 것으로 조사되었다.