• 한국환경농학회지
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• 제38권3호
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• pp.185-196
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• 2019

BACKGROUND: This study investigated the effects of rice genetically modified to be resistant against rice blast and rice bacterial blight on the soil microbial community. A comparative analysis of the effects of rice genetically modified rice choline kinase (OsCK1) gene for disease resistance (GM rice) and the Nakdong parental cultivar (non-GM rice) on the soil microbial community at each stage was conducted using rhizosphere soil of the OsCK1 and Nakdong rice. METHODS AND RESULTS: The soil chemistry at each growth stage and the bacterial and fungal population densities were analyzed. Soil DNA was extracted from the samples, and the microbial community structures of the two soils were analyzed by pyrosequencing. No significant differences were observed in the soil chemistry and microbial population density between the two soils. The taxonomic analysis showed that Chloroflexi, Proteobacteria, Firmicutes, Actinobacteria, and Acidobacteria were present in all soils as the major phyla. Although the source tracking analysis per phylogenetic rank revealed that there were differences in the bacteria between the GM and non-GM soil as well as among the cultivation stages, the GM and non-GM soil were grouped according to the growth stages in the UPGMA dendrogram analysis. CONCLUSION: The difference in bacterial distributions between Nakdong and OsCK1 rice soils at each phylogenetic level detected in microbial community analysis by pyrosequencing may be due to the genetic modification done on GM rice or due to heterogeneity of the soil environment. In order to clarify this, it is necessary to analyze changes in root exudates along with the expression of transgene. A more detailed study involving additional multilateral soil analyses is required.

• 한국습지학회지
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• 제14권1호
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• pp.35-45
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• 2012

멸종위기식물이고, 한국 특산속 식물인 제주고사리삼의 생육 환경과, 식물사회학적 군락조사를 통해 그 분포 입지와 생태적 특성을 밝히고자 제주도의 조천-선흘 곶자왈 습지대에서 12개의 영구 방형구를 설치하고 분포입지, 식생 종조성, 식피율, 습지의 면적, 깊이와 경사도, 개체군 밀도를 조사하였다. 제주고사리삼 자생지의 입지환경은 물이 고였다가 마르는 독립된 소택지로 여러 가지 모양을 가지며 습지면적은 150-$400m^2$로 좁았고, 해발고도는 88-165m, 깊이는 0.4-2.0m, 경사는 3-$10^{\circ}$로 완만하였다. 토양은 수분을 항시 보유하고 있었다. 제주고사리삼은 소택지내에서 수관이 밀폐된 가장자리에 주로 군생하며, 개체수는 1-423개로 자생지에 따라 다르게 나타났다. 식물군락은 참느릅나무군락, 꾸지뽕나무군락, 찔레꽃군락, 소엽맥문동군락(이상 목본성), 자금우군락(초본성)의 5개로 구분되었고, 식피율은 80-100%로 매우 높았다. 이상으로 볼 때 제주고사리삼은 지속적인 수분공급과 어느 정도의 광이, 특히 낙엽수의 휴면기 때, 유입되는 환경에서만 살 수 있음을 의미한다. 또한 식물체의 크기가 5cm 이내로 작아 낙엽의 퇴적과 같은 작은 환경변화로도 생육에 큰 지장이 있을 정도로 예민한 종이고, 장기적으로는 상록활엽수로의 천이가 진행될 경우 그 생육지는 더욱 감소할 것으로 예상되어 이에 대한 대책이 필요하다.

• Journal of Microbiology
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• 제42권4호
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• pp.278-284
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• 2004

Changes in the soil bacterial community of a coniferous forest were analyzed to assess microbial responses to wildfire. Soil samples were collected from three different depths in lightly and severely burned areas, as well as a nearby unburned control area. Direct bacterial counts ranged from $3.3­22.6\times10^8\;cells/(g{\cdot}soil).$ In surface soil, direct bacterial counts of unburned soil exhibited a great degree of fluctuation. Those in lightly burned soil changed less, but no significant variation was observed in the severely burned soil. The fluctuations of direct bacterial count were less in the middle and deep soil lay­ers. The structure of the bacterial community was analyzed via the fluorescent in situ hybridization method. The number of bacteria detected with the eubacteria-targeted probe out of the direct bacterial count varied from $30.3\;to\;84.7\%,$ and these ratios were generally higher in the burned soils than in the unburned control soils. In the surface unburned soil, the ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ Cytoph­aga-Flavobacterium group, and other eubacteria groups to total eubacteria were 9.9, 10.6, 15.5, 9.0, and $55.0\%,$ respectively, and these ratios were relatively stable. The ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ and Cytophaga-Flavobacterium group to total eubacteria increased immediately after the wildfire, and the other eubacterial proportions decreased in the surface and middle layer soils. By way of contrast, the composition of the 5 groups of eubacteria in the subsurface soil exhibited no significant fluctuations dur­ing the entire period. The total bacterial population and bacterial community structure disturbed by wildfire soon began to recover, and original levels seemed to be restored 3 months after the wildfire.

• Ocean and Polar Research
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• 제34권3호
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• pp.275-286
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• 2012

Over the last 20 years there have been more than 3000 peer-reviewed papers relating to climate change and biodiversity published, and still the numbers are increasing. However, most studies focused on the impacts of climate change at population or community levels, and the results invariably reveal that there has been, or will be, a negative effect on the structure and pattern of biodiversity. Moreover, the climate change models and statistical analyses used to test the impacts are only newly developed, and the analyses or predictions can often be misled. In this review, I ask why an individual's life history is considered in the study how climate change affects biodiversity, and what ecological factors are impacted by climate change. Using evidence from a range of species, I demonstrate that diverse life history traits, such as early growth rate, migration/foraging behaviour and lifespan, can be shifted by climate change at individual level. Particularly I discuss that the optimal decision under unknown circumstance (climate change) would be the reduction of the ecological fitness at individual level, and hence, a shift in the balance of the ecosystem could be affected without having a critical impact on any one species. To conclude, I summarize the links between climate changes, ecological decision in life history, the revised consequence at individual level, and discuss how the finely-balanced relationship affects biodiversity and population structure.

• 농촌계획
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• 제28권1호
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• pp.37-47
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• 2022

The purpose of this study is to introduce the concept of community resilience to rural society and build an index suitable for the reality of rural areas. Furthermore, by calculating the importance of evaluation factors, it was attempted to present priorities and alternatives for each evaluation factor. By stratifying the derived indicators, a survey was conducted targeting 20 researchers, practitioners, and public officials, three groups of experts working in rural areas who were well aware of the realities and problems of rural areas. In the survey, a pairwise comparison was performed to compare factors 1:1 to calculate the importance, and for rational and consistent decision-making, decisions were made in the 9-grade section. Using the collected data, consistency analysis that can evaluate reliability in the decision-making process and the relative weight of evaluation factors were calculated through AHP analysis. As a result of the analysis, as a result of examining the priority of final importance by summarizing the importance of all evaluation factors, 'Income creation using resources' > 'Population Characteristics' > 'Tolerance' > 'External Support' > 'Social Accessibility' > 'Physical Accessibility' > 'Community Competence' > 'Infrastructure' > 'Leader Competence' > 'Natural Environment' was derived in the order. In the study dealing with urban community resilience indicators, social aspects such as citizen participation, public-private cooperation, and governance were presented as the most important requirements, but this study differs in that the 'income creation' factor is derived as the most important factor. This can be seen through the change in the income difference between rural and urban areas. The income structure of rural areas has changed rapidly, and it is now reaching a very poor level, so it is necessary to prepare alternatives to 'income creation' in the case of rural areas. Unlike urban indicators, 'population characteristics' and 'tolerance' were also derived as important indicators of rural society. However, there are currently no alternatives to supplement the vulnerability by strengthening the resilience of rural communities. Based on the priority indicators derived from the study, we tried to suggest alternatives necessary for rural continuity in the future so that they can be supplemented step by step.

• The Korean Journal of Ecology
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• 제17권3호
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• pp.415-424
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• 1994

Community structure, size and age distribution of tree species of the subalpine Korean fir (Abies koreana) forest at the elevation of 1, 400~1, 700m were strudied in the north-west side of Chonwangbong Peak (1915m) in Mt. Chiri for the purpose of better understanding of the population dynamics of Abies koreana. Eight 20m X 20m permanent quadrats were established in 1991, and trees $\geq$ 2.5cm DBH for all species were marked with numbered aluminum tag, and saplings of Korean fir and Korean pine (Pinus koraiensis) were also tagged with aluminum sheet. These two conifer species comprised more than 60% of the total density and total basal area of the community. Quercus mongolica and Acer pseudo-sieboldianum were subdominats. Oridination study showed that cool temperate species such as Sorbus commixta, Betula costata, Acer tschonoskii and Acer ukurunduense occurred in close association with Abies koreana and Pinus koraiensis. Major tree species, especially Abies koreana and Pinus koraiensis, were well represented in samller size classes, indicating that they were regenerating well. Age distributuion of the Abies koreana and Pinus koraiensis showed that the former has longer physiological longevity than the latter, and that establishment were episodic and varied with sites, which implies the importance of the role of natural and artificial disturbances in this Abies kireana forest.

• 한국환경과학회지
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• 제22권12호
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• pp.1551-1559
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• 2013

This study was conducted to compare benthic macroinvertebrate communities of urban stream and nature stream in Daegu-si, Gyeongju-si, Gyeongsan-si, Andong-si, and Cheongsong-gun. The survey was carried out with 12 points in total six points for urban stream, six points for nature stream from Sept. 2011 to July 2012. In the urban stream were 33 species belonged to 24 families, 11 orders, 7 classes and 4 phyla while in the nature stream were 73 species belonged to 38 families, 12 orders, 5 classes and 4 phyla. In general, species diversity indices and species richness indices appeared low in urban stream but dominance indices was high. Functional feeding groups and Habitat Oriented Groups appeared comparatively simple in urban stream rather than nature stream. As a result of analysis of community stability, species included to area I and area III equally appeared in nature stream while species included to area I mostly appeared in urban stream. An analysis of the correlation between the population density and the number of species, the population number and biological indicators such as DI, H', RI, and ESB revealed that there was a significant correlativity with the diversity index and a very high correlativity with the number of species, abundance index and the ESB. On the other hand, the population number and the dominance index did not reveal any correlativity. For indicator species, Hydroptila KUa, Physa acuta appeared in urban stream while Paraleptophlebia chocolata, Epeorus pellucidus appeared in nature stream.

• The Korean Journal of Ecology
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• 제14권1호
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• pp.25-38
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• 1991

Berchemia berchemiaefolia is a native a native rare plant which has been designating as the Natural Monument, No. 266, since 1980. The floristic composition, population structure and maintenance mechanism of the Berchemia berchemiaefolia forest were investigated in conjunction with the habitat consisted of the block field or screes. Through the present study, the authors found a new habitat of Berchemia berchemiaefolia in the northeastern slope on Mt. Kumdansan located at Hajeok-ri, Cheongcheon-myeon, Koesan-gun, chungbuk province. Gravels consisted of the block field belonged to granule, pebble and cobble as the range of grain size, $\Phi$=-1.5~6.6 values. The tree layer of Berchemia berchemiaefolia community was mainly composed of Quercus variabilis, Pinus densiflora and Q. serrata including Berchemia berchemiaefolia and of this community were similar to that of Q. variabilis. By the age distribution, it was considered that the community was a discontinued one as the pattern of distribution was a normal distribution type(N type). Phenological cycle including leafing, blooming and seed-bearing period between both sites of block field and valley or close canopy showed some differences. The seed production of Berchemia berchemiaefolia was 8, 655, 000 seeds/ha/year, but only 406, 000 seeds/ha/year of them were developed as saplings, and only 4 saplings were developed to mature trees.

• 한국습지학회지
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• 제19권4호
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• pp.409-422
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• 2017

월동수조류의 군집에 영향을 미치는 환경요인을 파악하기 위하여 원주천을 6구간으로 나누어 조류의 군집 및 하천의 크기, 기온, 수질, 저서성무척추동물, 어류를 조사하였다. 원주천에서 수조류의 군집에 영향을 미치는 요인은 하천의 구조 및 기온, 수질이었다. 하천의 구조 중 월동수조류의 군집에 가장 큰 영향을 미치는 요인은 저수로의 폭과 흐르는 물의 넓이인 유폭으로 그 넓이가 넓을수록 월동수조류의 종수와 개체수가 많았으며, 둔치의 폭이 넓어서 저수로의 폭과 유폭이 좁아질수록 개체수는 적었다. 월동기의 기온 변화는 하천의 결빙으로 이어지므로 수조류의 군집에 영향을 미쳤으며 결빙되지 않는 구간은 기온의 하강과 상승에 뚜렷한 증가와 감소를 보였다. 수질조사 항목 중 pH, 수온, COD, BOD, T-N, T-P, 총대장균의 수치는 하류로 갈수록 증가하여 월동수조류의 개체수 증가와 높은 상관성을 보였는데 하류에 위치한 하수처리장의 영향으로 S6의 수질검사 항목의 수치가 높게 나타났으며 월동수조류의 개체수 또한 가장 많이 관찰되었다. 하수처리장 배출수는 수질에 상당한 영향을 미치는 것으로 보이는데 T-N을 비롯하여 여러 항목 수치의 증가는 하천의 영양화를 촉진시키고 이로 인해 유기물질의 축적과 수서생물의 증식을 가져옴으로 이를 먹이원으로 하는 월동수조류의 증가 원인이 될 수 있을 것으로도 여겨진다. 저서성 대형무척추동물의 군집과 어류의 군집은 원주천 모든 구간에서 대체적으로 양호한 것으로 나타났으나 월동수조류의 군집과의 상관성을 보이지 않았다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제11권3호
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• pp.66-77
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• 2006

최근에 적용된 지하수 미생물의 군집구조를 밝히는 분자생물학적 및 생화학적 방법들에 대해서 알아보았고 그 결과로서 지하수의 주요 오염물질에 따른 활성화된 미생물군집들이 무엇인지를 밝힌 연구논문들을 종합하여 정리하였다. PCR에 의한 유전자 증폭기술의 발달로 배양 없이 미생물 종류와 개체군을 파악할 수 있게 되었고 각종 finger-printing 방법 (DGGE, SSCP, RISA, microarray) 과 지방산분석법 (PLFA/FAME)을 이용하여 활성화 된 미생물군집구조를 분석하였으며 FISH 등의 방법으로 특정균의 활성도를 알아본 사례들을 조사하였다. 대표적인 지하수오염물질인 유류성분 (n-alkanes, BTEX, MTBE, ethanol)과 염소계 용매 (TCE, PCE, PCB, CE, carbon tetrachloride, chloro-benzene) 등으로 오염되었을 때 우점하는 지하수 미생물상에 대해 보고된 내용을 포함하였다.