Abstract
Poster session 3 – Scale and Biogeography
P 19
Diversity and spatial scaling of the soil metagenome
F. Monroy1,2, T.M. Bezemer2, W.H. van der Putten2,3
1Universidade de Vigo, Ecoloxía e Bioloxía Animal, Vigo, Spain
2Netherlands Institute of Ecology, Heteren, Netherlands
3Wageningen University, Nematology, Wageningen, Netherlands
Introduction: Microorganisms constitute the main source of biodiversity on Earth and soils are considered to harbour
most of this diversity. However, our knowledge about the rules governing diversity patterns comes mainly from the study
of aboveground multicellular, conspicuous organisms. Whether soil microorganisms show biogeographical patterns and
how these patterns influence their diversity are main questions in ecology. Considering the wide range of methods
available to assess the diversity of microorganisms -from the use of selective-culture conditions to single-gene analyses
and metagenomics- we discuss which diversity patterns are soundly supported and which ones might be revolutionized
by the use of metagenomic data.
Material/Methods: We focused on the bacterial communities of temperate semi-natural grasslands in southern UK,
where the occurrence of different diversity patterns was assessed by PCR-DGGE analysis of 16S rRNA.
Results: In the studied grasslands, 1) the presence/absence of bacterial taxa was related to variation in soil chemistry
and plant community composition; 2) independently of the environmental factors, the similarity of bacterial communities
decreased with geographic distance in grasslands separated between 1 and ~200 km, and 3) the diversity of bacteria
was much lower at the cm scale than expected if the abundances of the different taxa were randomly distributed.
Discussion/Conclusions: The results support the view that variation in community composition in response to
environmental factors is a common pattern in microorganisms. The choice between different screening methodologies or
their combination will probably affect the precision rather than the ability to recognize the pattern itself. On the other
hand, the distance effect on community similarity is a striking result for microorganisms, considering their expected
dispersion abilities and the relatively short range of distances covered. The observed variation among community
similarities suggests that the estimation of distance effects may be limited by the number of taxa detected with our
methodology. Metagenomic data would overcome this limitation, probably showing that the distance-decay in community
similarity is more common than thought. Moreover, as we showed, this pattern may be associated with the occurrence of
strong bacterial interactions at very small spatial scales. A systematic validation of the idea that local processes are
major determinants of microbial biogeographical patterns is waiting for the potential of metagenomics to provide
extensive information on the communities of bacteria and other soil microorganisms.
Original language | English |
---|---|
Publication status | Published - 2010 |
Event | Soil Metagenomics 2010 - Duration: 8 Dec 2010 → 10 Dec 2010 |
Conference
Conference | Soil Metagenomics 2010 |
---|---|
Period | 8/12/10 → 10/12/10 |