The Science

In the Arctic, environmental factors governing microbial degradation of soil carbon in active layer and permafrost are poorly understood. Here a team of scientists from the Next-Generation Ecosystem Experiments (NGEE)–Arctic project determined the functional potential of soil microbiomes horizontally and vertically across a cryoperturbed polygonal landscape in Barrow, Alaska.

The Impact

The role of ecosystem structure in microbial activity related to greenhouse gas production is poorly understood. Here, the scientists show that microbial communities and ecosystem function vary across fine-scale topography in an Arctic polygonal tundra.

Summary

With comparative metagenomics, genome binning of novel microbes, and gas flux measurements, a team of scientists from the NGEE-Arctic show that microbial greenhouse gas production is strongly correlated to landscape topography. While microbial functions such as fermentation and methanogenesis were dominant in wetter polygons, in drier polygons genes for carbon mineralization and methane (CH₄) oxidation were abundant. The active layer microbiome was poised to assimilate nitrogen and not to release nitrous oxide (N₂O), reflecting low N₂O flux measurements. These results provide mechanistic links of microbial metabolism to greenhouse gas fluxes that are needed for the refinement of model predictions.

Principal Investigator

Neslihan Tas
Lawrence Berkeley National Laboratory
ntas@lbl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

The Next-Generation Ecosystem Experiments (NGEE)–Arctic project is supported by the Office of Biological and Environmental Research within the U.S. Department of Energy (DOE) Office of Science. The DOE Joint Genome Institute, a DOE Office of Science user facility, is supported through Contract No. DE-AC0205CH11231 to Lawrence Berkeley National Laboratory.

References