Jones, C.M., Graf, D., Bru, D., Philippot, L., Hallin, S. The unaccounted yet abundant nitrous oxide reducing microbial community - a potential nitrous oxide sink. ISME J. (2013), volume 7, pp. 417–426. doi: 10.1038/ismej.2012.125. Read the article
EcoFINDERS in SLU: Nyupptäckt mikrobgrupp oskadliggör växthusgas i marken (August 2014)
The scientific peer reviewed article Jones, C. M., Spor, A., Brennan, F. P., Breuil, M.-C., Bru, D., Lemanceau, P., Griffiths, B., Hallin, S. and Philippot, L. 2014. Recently identified microbial guild mediates soil N2O sink capacity. Nature Climate Change, 4:801-805 (read full paper here) received much attention and was cited in international as well as Swedish press.
At SLU in Sweden and INRA in Dijon, France research scientists have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2).
Nitrous oxide (N2O) is a potent greenhouse gas that is also responsible for destroying the ozone layer. INRA research scientists in Dijon have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2). These results, published inNature Climate Change in september 2014, underline the importance of microbial diversity to the functioning of soils and the services they deliver.
Nitrous oxide (N2O) is one of the principal greenhouse gases, alongside carbon dioxide (CO2) and methane (CH4); it is also responsible for destruction of the ozone layer. Terrestrial ecosystems contribute to about 70% of N2O emissions, at least 45% being linked to the nitrogen-containing products found in agricultural soils (fertilisers, slurry, manure, crop residues, etc.). "In order to lower emissions of N2O and develop more environmentally-friendly agriculture, it is important to understand the processes involved not only in its production but in its elimination," explain the scientists. This elimination can be achieved by micro-organisms living in the soil that are able to reduce N2O into nitrogen (N2), the gas that makes up around four-fifths of the air we breathe and which has no impact on the environment.
INRA scientists, working in collaboration with Swedish and Irish colleagues, have analysed 47 soil samples collected throughout Europe and demonstrated very considerable differences between these soils in terms of their capacities to eliminate N2O. Unlike other greenhouse gases such as carbon dioxide (CO2) or methane (CH4), the ability of soils to eliminate N2O and thus act as a sink for this greenhouse gas has been very little studied hitherto.
Their work has shown that this variability is linked to a new group of N2O-consuming micro-organisms. These organisms had been identified by the same research teams in 2013, but had never previously been taken into account in studies aiming at understanding N2O emissions. "We have discovered that it is both the diversity and the abundance of this new group of N2O-consuming micro-organisms that are important to the ability of soils to eliminate N2O," explains Laurent Philippot, an INRA researcher in Dijon.
This study has also helped to clarify the influence of the physicochemical properties of soils on the development of these micro-organisms. Thanks to a metagenomic approach and the analysis of several hundreds of thousands of DNA sequences, the scientists were also able to identify several groups of micro-organisms that could act as bioindicators for the capacity of European soils to transform N2O into N2. The team is currently working on identifying farming practices that could stimulate this new group of N2O-consuming micro-organisms, in order to ensure sustainable agricultural production.
All these findings underline the importance of the biodiversity of soil micro-organisms to the functioning of soils and the services they deliver. (INRA-France. "Greenhouse gases: New group of soil micro-organisms can contribute to their elimination." ScienceDaily. ScienceDaily, 27 August 2014.)
Further news articles about this scientific article can be found here:
European Soil Portal newsletter. JRC, Ispra, Italy. Newsletter
EcoFINDERS in ELN-FAB newsletter December 2012
EcoFINDERS in ELN-FAB newsletter February 2012
Soils provide numerous essential ecosystem services such as: primary production (including agricultural and forestry products); regulation of biogeochemical cycles (with consequences for the climate); water filtration; resistance to diseases and pests; and regulation of above-ground biodiversity.
However, soils are subjected to many threats, so there is an urgent need to preserve this resource which is not renewable at the Human time scale. The European Commission wants to define a policy for the sustainable management of soils with a view to adopting a legally binding Soil Framework Directive, such as exists for air and water. Scientific and technological knowledge on soil biodiversity and functioning in relation with the above mentioned ecosystem services is required to reach this goal.
Soils host a huge biodiversity (microbes and fauna) of which our understanding remains very limited. Our lack of knowledge is related to: the small size of the soilborne organisms; their immense diversity; the difficulty in isolating them; and the great heterogeneity of their habitats across different scales. However, recent progress in the molecular characterization of soil biodiversity offers the exciting prospect of exploring its complexity and better understanding its functioning.
The EcoFINDERS (Ecological Function and Biodiversity Indicators in European Soils) project will result in:
The soil biodiversity studied includes microbes (archaea, bacteria, fungi) and fauna (protozoa, microarthropods, nematodes, oligochaeta), and their relation with above-ground biodiversity.
The corresponding research combines three approaches:
This European project, coordinated by INRA, gathers together 23 partners from 10 European countries plus China, to harness expertise in ecology, biodiversity, environmental economy, modeling, bioinformatics and database management.
Dr. Philippe LEMANCEAU, project coordinator,
Tel. +33 3 80 69 30 56, firstname.lastname@example.org