Considering that 25% of Earth's terrestrial surface is underlain by permafrost (ground that has been continuously frozen for at least 2 years), our understanding of the diversity of microbial life in this extreme habitat is surprisingly limited. Taking into account the total mass of perennially frozen sediment (up to several hundred meters deep), permafrost contains a huge amount of buried, ancient organic carbon (Tarnocai et al., 2009). In addition, permafrost is warming rapidly in response to global climate change (Romanovsky et al., 2010), potentially leading to widespread thaw and a larger, seasonally thawed soil active layer. This concern has prompted the question: will permafrost thawing lead to the release of massive amounts of carbon dioxide (CO2) and methane (CH4) into the atmosphere? This question can only be answered by understanding how the microbes residing in permafrost will respond to thaw, through processes such as respiration, fermentation, methanogenesis and CH4 oxidation (Schuur et al., 2009).

Here we address how combining information about microbial identity (from phylotyping) and metabolic potential (from metagenomes) with information on what genes are expressed and functioning (from metatranscriptomes and metaproteomes) (VerBerkmoes et al., 2009; Jansson, 2011) has begun to open a new window of opportunity to map and predict biochemical processes in soils. They provide the tools to distinguish among different mechanisms for increased organic matter decomposition caused by increasing temperature (Conant et al., 2011). Two potential applications of this systems biology framework, discussed below, illustrate how these molecular techniques could be used to improve our ability to model SOM degradation rates and mechanisms, and to predict changes in CH4 and CO2 emissions from thawing permafrost.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account
Continue with Google
Continue with ORCiD