https://repository.kopri.re.kr/handle/201206/5363 2026-04-22T08:28:04Z https://repository.kopri.re.kr/handle/201206/6358 Title: Variations in bacterial and archaeal communities along depth profiles of Alaskan soil cores Authors: Binu, M.; Lee, Yoo Kyung; Ahn, Jinho; Yang, Ji-Woong; Byun, Eunji; Kim, Yongwon; Kim, Mincheol Abstract: Understating the microbial communities and ecological processes that influence their structure in permafrost soils is crucial for predicting the consequences of climate change. In this study we investigated the bacterial and archaeal communities along depth profiles of four soil cores collected across Alaska. The bacterial and archaeal diversity (amplicon sequencing) overall decreased along the soil depth but the depth-wise pattern of their abundances (qPCR) varied by sites. The community structure of bacteria and archaea displayed site-specific pattern, with a greater role of soil geochemical characteristics rather than soil depth. In particular, we found significant positive correlations between methane trapped in cores and relative abundance of methanogenic archaeal genera, indicating a strong association between microbial activity and methane production in subsurface soils. We observed that bacterial phylogenetic community assembly tended to be more clustered in surface soils than in deeper soils. Analyses of phylogenetic community turnover among depth profiles across cores indicated that the relative influence of deterministic and stochastic processes was mainly determined by soil properties rather than depth. Overall, our findings emphasize that the vertical distributions of bacterial and archaeal communities in permafrost soils are to a large extent determined by the variation in sitespecific soil properties. 2018-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6180 Title: Chemical characterization of dissolved organic matter in moist acidic tussock tundra soil using ultra-high resolution 15T FT-ICR mass spectrometry Authors: Choi, Jung Hoon; Pack, Seung Pil; Jang, Kyoung-Soon; Jung, Ji Young; Lee, Yoo Kyung; Kim, Yun-Gon Abstract: Global warming is considered one of the most serious environmental issues, substantially mediating abrupt climate changes, and has stronger impacts in the Arctic ecosystems than in any other regions. In particular, thawing permafrost in the Arctic region with warming can be strongly contributing the emission of greenhouse gases (CO2 and CH4) that are produced from microbial decomposition of preserved soil organic matter (SOM) or are trapped in frozen permafrost soils, consequently accelerating global warming and abrupt climate changes. Therefore, understanding chemical and physical properties of permafrost SOM is important for interpreting the chemical and biological decomposability of SOM. In this study, we investigated dissolved organic matter (DOM) along the soil depth profile in moist acidic tussock tundra to better understand elemental compositions and distributions of the arctic SOM to evaluate their potential decomposability under climate change. To achieve ultra-high resolution mass profiles, the soil extracts were analyzed using a 15 Tesla Fourier transform ion cyclotron resonance mass spectrometer in positive and negative ion modes via electrospray ionization. The results of this analysis revealed that the deeper organic soil (2Oe1 horizon) exhibits less CHON class and more aromatic class compounds compared to the surface organic soils, thus implying that the 2Oe1 horizon has undergone a more decomposition process and consequently possessed the recalcitrant materials. The compositional features of DOM in the Arctic tundra soils are important for understanding the changes in biogeochemical cycles caused from permafrost changes associated with global warming and climate change. 2017-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5822 Title: Shifts in bacterial community structure during succession in a glacier foreland of the High Arctic Authors: Kim, Mincheol; Lee, Yoo Kyung; Kwon, Hye Young; Dominique Laffly; Jung, Ji Young Abstract: Primary succession after glacier retreat has been widely studied in plant communities, but bacterial succession is still poorly understood. In particular, few studies of microbial succession have been performed in the Arctic. We investigated the shifts in bacterial community structure and soil physicochemical properties along a successional gradient in a 100-year glacier foreland of the High Arctic. Multivariate analyses revealed that time after glacier retreat played a key role in associated bacterial community structure during succession. However, environmental filtering (i.e., pH and soil temperature) also accounted for a different, but substantial, proportion of the bacterial community structure. Using the functional trait-based approach, we found that average rRNA operon (rrn) copy number of bacterial communities are high in earlier successional stages and decreased over time. This suggests that soil bacterial taxa with higher rrn copy number have a selective advantage in early successional stages due to their ability of rapidly responding to nutrient inputs in newly exposed soils after glacier retreat. Taken together, our results demonstrate that both deglaciation time and environmental filters play key roles in structuring bacterial communities and soil bacterial groups with different ecological strategies occur in different stages of succession in this glacier foreland. 2017-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/8105 Title: Arctic Note Authors: Lee, Yoo Kyung; Yoon, Young Jun; Choi, Taejin; Jin, Young Keun; Chung, Ji Woong; Jung, Ji Young; Lee, Won Young; Lee, Khanghyun; Woo, Jusun; Yang, Eun Jin; Seo, Hyunkyo; Seo, Won-Sang; Park, Tae-Yoon S.; Park, Sangjong; Park, Ki-Tae; Nam, Seung-il; Nam, Sungjin; Kim, Ho-Sun; Kim, Hyun-cheol; Kim, Jeong-Han; Kim, Seong-Joong; Kim, Baek-Min; Kim, Kitae; 권민정; Kang, Sung-Ho 2017-01-01T00:00:00Z