title: Vertical distribution of bacterial community is associated with the degree of soil organic matter decomposition in the active layer of moist acidic tundra.
abstract: The increasing temperature in Arctic tundra deepens the active layer, which is the upper layer of permafrost soil that experiences repeated thawing and freezing. The increasing of soil temperature and the deepening of active layer seem to affect soil microbial communities. Therefore, information on soil microbial communities at various soil depths is essential to understand their potential responses to climate change in the active layer soil. We investigated the community structure of soil bacteria in the active layer from moist acidic tundra in Council, Alaska. We also interpreted their relationship with some relevant soil physicochemical characteristics along soil depth with a fine scale (5 cm depth interval). The bacterial community structure was found to change along soil depth. The relative abundances of Acidobacteria, Gammaproteobacteria, Planctomycetes, and candidate phylum WPS-2 rapidly decreased with soil depth, while those of Bacteroidetes, Chloroflexi, Gemmatimonadetes, and candidate AD3 rapidly increased. A structural shift was also found in the soil bacterial communities around 20 cm depth, where two organic (upper Oi and lower Oa) horizons are subdivided. The quality and the decomposition degree of organic matter might have influenced the bacterial community structure. Besides the organic matter quality, the vertical distribution of bacterial communities was also found to be related to soil pH and total phosphorus content. This study showed the vertical change of bacterial community in the active layer with a fine scale resolution and the possible influence of the quality of soil organic matter on shaping bacterial community structure.
authors: Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea.|School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors: Hye Min
authors: HM
authors: Kim
authors: Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors: Min Jin
authors: MJ
authors: Lee
authors: Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea.
authors: Ji Young
authors: JY
authors: Jung
authors: Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea.
authors: Chung Yeon
authors: CY
authors: Hwang
authors: Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea.
authors: Mincheol
authors: M
authors: Kim
authors: Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors: Hee-Myong
authors: HM
authors: Ro
authors: School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors: Jongsik
authors: J
authors: Chun
authors: Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea. yklee@kopri.re.kr.
authors: Yoo Kyung
authors: YK
authors: Lee
mesh_terms: D061271:Acidobacteria / Q000235:genetics / Q000302:isolation & purification; D000413:Alaska; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D002244:Carbon / Q000032:analysis; D057231:Climate Change; D020563:Gammaproteobacteria / Q000235:genetics / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology; D065946:Permafrost / Q000382:microbiology; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D065929:Tundra
chemical_list: D012987:Soil; D002244:Carbon
keywords: bacterial community structure; depth profile; soil organic matter; soil pH; total phosphorus