https://repository.kopri.re.kr/handle/201206/5537 2026-03-06T06:11:36Z 2026-03-06T06:11:36Z Kim, Mincheol Lim, Hyun-Soo Hyun, Chang-Uk Cho, Ahnna Noh, Hyun-Ju Hong, Soon Gyu Kim, Ok-Sun https://repository.kopri.re.kr/handle/201206/9646 2022-03-24T07:14:22Z 2019-03-01T00:00:00Z

Title: Local-scale variation of soil bacterial communities in ice-free regions of maritime Antarctica Authors: Kim, Mincheol; Lim, Hyun-Soo; Hyun, Chang-Uk; Cho, Ahnna; Noh, Hyun-Ju; Hong, Soon Gyu; Kim, Ok-Sun Abstract: The majority of biogeographic studies in Antarctic terrestrial ecosystems have focused on macroscopic eukaryote taxa. In contrast, microbial taxa have been almost neglected or examined without sufficient spatial coverage. Here, we examined the spatial distribution of soil bacterial communities and their relation to local environmental gradients in ice-free regions of the maritime Antarctic. Soils in this region were dominated by Actinobacteria and Proteobacteria, which are typically found in Antarctic soils. Notably, candidate divisions AD3 and WPS-2, which rarely occur in other biomes, were found in high abundance in acidic surface soils. Soil pH and total organic carbon (TOC) were the primary drivers of the bacterial community structure and various geochemical variables also played important roles in structuring bacterial community composition. Bacterial communities were significantly correlated to measured environmental variables, most of which are spatially structured at the local spatial scale (0.5？8 km). This suggests that spatial heterogeneity of environmental factors is an important driver of shifts in bacterial communities. Although various sets of environmental variables were related to bacterial communities, a large proportion of community variation remained unexplained. This indicates that bacterial communities in Antarctic soils may be governed by other biotic or abiotic factors which are not typically measured in other biome studies.

2019-03-01T00:00:00Z Kim, Dockyu Park, Ha Ju Youn, Ui Joung Hong, Soon Gyu https://repository.kopri.re.kr/handle/201206/12363 2022-03-24T07:15:10Z 2018-01-01T00:00:00Z

Title: Artificial Warming Effect on Microbial Community and Humic Substance Degradation in Maritime Antarctic Soil in King George Island Authors: Kim, Dockyu; Park, Ha Ju; Youn, Ui Joung; Hong, Soon Gyu Abstract: Although the maritime Antarctic has undergone rapid warming, the effects on indigenous soil-inhabiting microorganisms are not well known. Artificial warming experiments using open-top chamber (OTC) have been performed on the Fildes Peninsula in the maritime Antarctic since 2008. When the soil temperature was measured at a depth of 25 cm during the 20132015 summer seasons, the mean temperature inside OTC (OTC-In) increased by approximately 0.8ºC compared with outside OTC (OTC-Out), while soil chemical and physical characteristics were not changed. Soils from OTC-In and OTC-Out were subjected to analysis for change in microbial community and degradation rate of humic substances (HS, the largest pool of recalcitrant organic carbon). Archaeal and bacterial communities in OTC-In were minimally affected by warming compared with those in OTC-Out, with archaeal methanogenic Thermoplasmata slightly increased in abundance. The abundance of heterotrophic fungi Ascomycota was significantly altered in OTC-In. Total bacterial and fungal biomass in OTC-In increased by 20% compared to OTC-Out, indicating that this may be due to increased microbial degradation activity for soil organic matter (SOM) including HS, which would result in the release of more low-molecular-weight growth substrates from SOM. Despite the effects of warming on the microbial community over the 8-years-experiments warming did not induce any detectable change in content or structure of polymeric HS.

2018-01-01T00:00:00Z Kim, Dockyu Park, Ha Ju Lee, Chang Woo Hong, Soon Gyu https://repository.kopri.re.kr/handle/201206/12352 2022-03-24T07:15:16Z 2018-01-01T00:00:00Z

Title: Soil temperature increase effects on maritime Antarctic soil microbial community and humic acid degradation Authors: Kim, Dockyu; Park, Ha Ju; Lee, Chang Woo; Hong, Soon Gyu Abstract: Soil humic substance (HS) is the largest constituent of soil organic matter. A major extractable component, humic acid (HA), of HS is dark brown to black high molecular weight organic polymer. To assess the effects of warming both on HA degradation and microbial community, microcosm beakers with HA-rich soils from King George Island in the maritime Antarctic, were incubated at elevated temperature of 5C and 8C, compared to the soil temperature (below 2.0C) during thawing period. Under the microcosm systems, HA content steadily decreased to approximately 63% and 55%, compared to untreated control (100%, 287.0±2.8 mg/g soil), until 90 days-incubation at 5C and 8C, respectively, presumably by microbial degradation process. Culture-independent community analysis of 16S rRNA genes showed that, during the microcosm experiments, the relative abundances of bacterial phyla Proteobacteria (copiotrophic) and Actinobacteria (polymer-degrading) slightly increased and decreased, respectively, in parallel with the incubation temperature rising to 5C and 8C. In contrast, archaeal community, dominated by phylum Thaumarchaeota, hardly responded to the soil temperature increase, indicating that bacterial community was much more affected than archaea by warming, although fungal response was not consistent. Culture-dependent community analyses were subsequently performed for the indigenous bacteria at 5C and 8C which were enriched in an artificial mineral medium containing HA. Consequentially, addition of HA resulted in a rapid increase of Proteobacteria dominance at both 5C and 8C, with the relative abundance of class Alphaproteobacteria-related bacteria being highly increased to over 72.7% among Proteobacteria (100%) under HA-degradation process. The overall results of this study indicate that HA degradation is in progress by bacteria in maritime Antarctic soil, and soil temperature rise by global climate change can change the bacterial community structure and HA degradation rate

2018-01-01T00:00:00Z Kim, KwanSoo Ju, Hyeon Tae Hong, Soon Gyu Lee, Joohan https://repository.kopri.re.kr/handle/201206/12351 2022-03-24T07:13:20Z 2018-01-01T00:00:00Z

Title: Bio-geophysical mapping in the King-Sejong Station Authors: Kim, KwanSoo; Ju, Hyeon Tae; Hong, Soon Gyu; Lee, Joohan Abstract: 우리나라 최초의 남극 기지인 세종과학기지가 위치한 킹조지섬은 남극해류에 영향으로 강수량이 많고 날씨가 급변하며 남위 62도에 위치하여 남반구의 여름엔 비교적 온도가 높은 편이다. 많은 강수량과 높은 온도의 영향으로 식생의 분포가 넓으며 종류도 다양하다. 대표적인 식생으로는 이끼와 지의류가 있는데 이 생물들은 지하의 수분분포에 따라 많은 영향을 받는다. 연구지역은 신생대 초기에서 중기 사이에 발생한 화산쇄설물과 퇴적물로 이루어져 있으며 수분 공급처는 크게 세 가지로 직접적인 강수, 빙하가 녹은 물과 대기의 단열팽창현상인데 올해 2월 중순 총 강수량은 5.7mm로 여름철에는 특히 빙하가 녹은 물에 영향이 가장 크다. 연구지역의 이끼 서식지는 빙하에 가까우며 지의류에 서식지는 해안쪽으로 분포한다. 이것이 지하 내부의 수분분포와 관련된 것으로 가정 후 2018년 2월 중순경 땅이 가장 많이 녹은 시기에 측선 길이는 40m이며 1m 전극 간격의 웨너배열법을 사용한 전기비저항탐사, 500MHz 안테나를 사용한 레이다탐사, EM38장비를 이용한 전자탐사를 실시하였다. 동토층의 깊이가 얕게는 0.8m부터 깊게는 1.5m로 많은 차이를 보였는데 동토층의 깊이가 수분량에 큰 영향을 받는 것으로 나타났으며 특정 위치의 활동층 내에 존재한 두께 5~7cm 가량의 퇴적층 또한 동토층에 영향을 주었고 지표의 구조토 형성에도 영향을 준 것으로 보인다.

2018-01-01T00:00:00Z