METHANOgenic Biodiversity and activity in Arctic, subarctic and Subantarctic Ecosystems affected by climate change

Publishable summary: 

Methane emissions from aquatic and terrestrial ecosystems play a crucial role in global warming, which is particularly affecting high-latitude ecosystems. As major contributors to methane emissions in natural environments, the microbial communities involved in methane production and oxidation deserve a special attention. Microbial diversity and activity are expected to be strongly affected by the, already observed (and further predicted), temperature increase in high-latitude ecosystems, eventually resulting in disrupted feedback methane emissions.

The METHANOBASE project has been designed to investigate the intricate relations between microbial diversity and methane emissions in Arctic, Subarctic and Subantarctic ecosystems, under natural (baseline) conditions and in response to simulated temperature increments. To achieve this highly challenging purpose, the METHANOBASE project relies on the use of state-of-the-art molecular tools and on a multidisciplinary team including experts from Europe (France, Belgium, Norway) and South America (Chile, Uruguay), as well as local partners in Siberia, Alaska and Patagonia for field expedition support. The project was designed to achieve the following specific objectives:

  • To establish the link between the methane-linked microbial community structure, the local environmental conditions and the in situ methane emission rates
  • To compare the methane-linked microbial ecosystems from Arctic, Subarctic and Subantarctic ecosystems
  • To assess the impact of projected global warming on microbial diversity and methane production/ oxidation activities
  • To identify sentinel/indicator species, exhibiting critical response to global change
  • To survey the baseline biodiversity and function potentialities of microbial communities involved in methane emissions in unexplored high-latitude ecosystems

During the first year, the METHANOBASE consortium was mostly dedicated to field work. Three field campaigns were successfully conducted in Patagonia (Chile), Alaska (United States of America) and Siberia (Russia). A total number of 56 ecosystems were investigated, including lake, peatland and soil ecosystems. Methane emissions as well as several physico-chemical parameters (eg pH, temperature, dissolved gases) were monitored in situ, while methanotrophic rates (methane oxidation rates) were quantified on site (i.e., in laboratories located close to the ecosystems). Almost 500 samples were collected for further characterization, which is mostly in progress. The extended characterization of samples encompasses DNA extraction and high-throughput sequencing to assess the Bacteria and Archaea biodiversity, physico-chemical analyses, methanotrophic and methanogenic incubations at different temperatures to mimic climate change, and a meta-omic approach for a selected subset of samples.

METHANOBASE is expected to give insights into the scientific knowledge of the methane-linked biodiversity and into the understanding of the biodiversityfunction link in the context of global change. The results will help to better understand the potential effect of global warming on microbial methane production, and its potential feedback on global changes. The experimental data generated both on the field and in the lab can subsequently be used as inputs of local to mesoscale models of emission simulation, in order to improve the accuracy of methane emission predictions in the context of global changes.