• Reduce text

    Reduce text
  • Restore text size

    Restore text size
  • Increase the text

    Increase the text
  • Print


Large-scale diversification processes affecting soil bacterial communities

The spatial distribution of soil microbial communities, and the processes involved in this distribution, are still generally unknown at a large scale (landscape, region, territory).  We have shown for the first time that the taxa-area relationship was significant at a large scale in the case of bacterial communities, and was positively correlated to the diversity and heterogeneity of soil habitats.

Un profil de sol constitué  de mottes de terre et d'aggrégats est un sysytème complexe vivant présentant des habitats imbriqués pour la microflore et la faune du sol.. © INRA, CLUZEAU Daniel
Updated on 08/27/2014
Published on 08/11/2014

One of the goals of modern microbial ecology is to better define and understand the processes that generate and maintain soil microbial diversity.  To attain this goal, we took advantage of the RMQS (Soil Quality Monitoring Network - Réseau de Mesure de la Qualité des Sols) to characterise indigenous microbial communities in soil samples collected from throughout France (2200 soils sampled according to a systematic grid).  At this large scale, we were able to calculate the taxa-area relationship, a robust ecological law that can estimate the diversification of communities of living organisms as a function of sampling area and link this turnover to environmental parameters.

Such a relationship had never previously been demonstrated for soil bacteria, and its application enables a clearer identification and ranking of the large-scale diversification that affects these microbial organisms.

Results: During our study we adapted mathematical analyses to calculate the taxa-area relationship for soil bacterial communities based on community genotyping data.  In parallel, we also developed an innovative technique to calculate habitat diversity and heterogeneity, which we linked to the soil bacterial taxa-area relationship.  We were thus able to demonstrate that:

  • the taxa-area relationship was significant for bacterial communities at the scales of both France and geographical regions within the country,
  • the taxa-area relationship was significant and correlated positively to habitat diversity and heterogeneity,
  • the selection processes (environmental filters) and dispersal of species were involved in the large-scale diversification of soil bacterial communities.


Contact: Lionel Ranjard, UMR Agroecology