TY - JOUR

T1 - Disentangling the complexity of permafrost soil by using high resolution profiling of microbial community composition, key functions and respiration rates

AU - Müller, Oliver

AU - Bang-Andreasen, Toke

AU - White, Richard Allen

AU - Elberling, Bo

AU - Taş, Neslihan

AU - Kneafsey, Timothy

AU - Jansson, Janet K.

AU - Øvreås, Lise

N1 - CENPERMOA[2018]

PY - 2018

Y1 - 2018

N2 - Thawing permafrost can stimulate microbial activity, leading to faster decomposition of formerly preserved organic matter and CO2 release. Detailed knowledge about the vertical distribution of the responsible microbial community that is changing with increasing soil depth is limited. In this study, we determined the microbial community composition from cores sampled in a high Arctic heath at Svalbard, Norway; spanning from the active layer (AL) into the permafrost layer (PL). A special aim has been on identifying a layer of recently thawed soil, the transition zone (TZ), which might provide new insights into the fate of thawing permafrost. A unique sampling strategy allowed us to observe a diverse and gradually shifting microbial community in the AL, a Bacteroidetes dominated community in the TZ and throughout the PL, a community strongly dominated by a single Actinobacteria family (Intrasporangiaceae). The contrasting abundances of these two taxa caused a community difference of about 60%, just within 3 cm from TZ to PL. We incubated subsamples at about 5°C and measured highest CO2 production rates under aerobic incubations, yet contrasting for five different layers and correlating to the microbial community composition. This high resolution strategy provides new insights on how microbial communities are structured in permafrost and a better understanding of how they respond to thaw.

AB - Thawing permafrost can stimulate microbial activity, leading to faster decomposition of formerly preserved organic matter and CO2 release. Detailed knowledge about the vertical distribution of the responsible microbial community that is changing with increasing soil depth is limited. In this study, we determined the microbial community composition from cores sampled in a high Arctic heath at Svalbard, Norway; spanning from the active layer (AL) into the permafrost layer (PL). A special aim has been on identifying a layer of recently thawed soil, the transition zone (TZ), which might provide new insights into the fate of thawing permafrost. A unique sampling strategy allowed us to observe a diverse and gradually shifting microbial community in the AL, a Bacteroidetes dominated community in the TZ and throughout the PL, a community strongly dominated by a single Actinobacteria family (Intrasporangiaceae). The contrasting abundances of these two taxa caused a community difference of about 60%, just within 3 cm from TZ to PL. We incubated subsamples at about 5°C and measured highest CO2 production rates under aerobic incubations, yet contrasting for five different layers and correlating to the microbial community composition. This high resolution strategy provides new insights on how microbial communities are structured in permafrost and a better understanding of how they respond to thaw.

U2 - 10.1111/1462-2920.14348

DO - 10.1111/1462-2920.14348

M3 - Journal article

C2 - 29971895

AN - SCOPUS:85051040268

VL - 20

SP - 4328

EP - 4342

JO - Environmental Microbiology

JF - Environmental Microbiology

SN - 1462-2912

IS - 12

ER -