Permafrost Meta-Omics and Climate Change

Abstract

Permanently frozen soil, or permafrost, covers a large portion of the Earth's terrestrial surface and represents a unique environment for cold-adapted microorganisms. As permafrost thaws, previously protected organic matter becomes available for microbial degradation. Microbes that decompose soil carbon produce carbon dioxide and other greenhouse gases, contributing substantially to climate change. Next-generation sequencing and other -omics technologies offer opportunities to discover the mechanisms by which microbial communities regulate the loss of carbon and the emission of greenhouse gases from thawing permafrost regions. Analysis of nucleic acids and proteins taken directly from permafrost-associated soils has provided new insights into microbial communities and their functions in Arctic environments that are increasingly impacted by climate change. In this article we review current information from various molecular -omics studies on permafrost microbial ecology and explore the relevance of these insights to our current understanding of the dynamics of permafrost loss due to climate change.

Species interactions and distinct microbial communities in high Arctic permafrost affected cryosols are associated with the CH4 and CO2 gas fluxes

“…Arctic warming and wetting/drying will influence whether these soils act as CH 4 sinks or sources (Lara et al, 2015;Natali et al, 2015). Warming will likely increase the amount of C lost to the atmosphere from permafrost soils; however, the ratio of CH 4 :CO 2 released is currently uncertain and would likely be determined by the geomorphology, hydrology, vegetation and microbiology of these soils (Lara et al, 2015;Natali et al, 2015;Mackelprang et al, 2016). Permafrost thaw would affect soil topography and increase moisture content in areas with high ice content in the permafrost but thaw can also induce drying via drainage and changes in hydrology in parts of the Arctic (Natali et al, 2015;Kittler et al, 2017).…”

Networking our science to characterize the state, vulnerabilities, and management opportunities of soil organic matter

“…Density and size fractionation techniques have helped to distinguish more rapidly cycled SOC from protected, less rapidly cycled C (Gregorich & Janzen, ; Jastrow, ; Kong, Six, Bryant, Denison, & van Kessel, ). More recently, in situ chemistry techniques have been used to investigate SOC transformation over timescales of hours to days (Hagerty et al., ; Mackelprang, Saleska, Jacobsen, Jansson, & Taş, ).…”

Microbial diversity — exploration of natural ecosystems and microbiomes

“…Permafrost locks away around half of global soil carbon, but these regions are beginning to thaw due to anthropogenic climate change, which is having a disproportionate impact on the poles. Soil warming has been shown to alter the diversity and function of microbial communities [42,43]. Thawing of permafrost soils will likely result in large-scale losses in soil carbon in the form of methane and carbon dioxide as a result of microbial activity [44].…”