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Aquatic Hyphomycete Species Are Screened by the Hyporheic Zone of Woodland Streams

Cornut, Julien and Chauvet, Eric and Mermillod-Blondin, Florian and Assemat, Fiona and Elger, Arnaud Aquatic Hyphomycete Species Are Screened by the Hyporheic Zone of Woodland Streams. (2014) Applied and Environmental Microbiology, 80 (6). 1949-1960. ISSN 0099-2240

(Document in English)

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Official URL: http://dx.doi.org/10.1128/AEM.03024-13


Aquatic hyphomycetes strongly contribute to organic matter dynamics in streams, but their abilities to colonize leaf litter buried in streambed sediments remain unexplored. Here, we conducted field and laboratory experiments (slow-filtration columns and stream-simulating microcosms) to test the following hypotheses: (i) that the hyporheic habitat acting as a physical sieve for spores filters out unsuccessful strategists from a potential species pool, (ii) that decreased pore size in sediments reduces species dispersal efficiency in the interstitial water, and (iii) that the physicochemical conditions prevailing in the hyporheic habitat will influence fungal community structure. Our field study showed that spore abundance and species diversity were consistently re- duced in the interstitial water compared with surface water within three differing streams. Significant differences occurred among aquatic hyphomycetes, with dispersal efficiency of filiform-spore species being much higher than those with compact or branched/tetraradiate spores. This pattern was remarkably consistent with those found in laboratory experiments that tested the influence of sediment pore size on spore dispersal in microcosms. Furthermore, leaves inoculated in a stream and incubated in slow-filtration columns exhibited a fungal assemblage dominated by only two species, while five species were codominant on leaves from the stream-simulating microcosms. Results of this study highlight that the hyporheic zone exerts two types of selec- tion pressure on the aquatic hyphomycete community, a physiological stress and a physical screening of the benthic spore pool, both leading to drastic changes in the structure of fungal community.

Item Type:Article
Additional Information:Thanks to American Society for Microbiology editor. The definitive version is available at http://aem.asm.org/content/80/6/1949
HAL Id:hal-00955568
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Ecole Nationale des Travaux Publics de l'Etat - ENTPE (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
French research institutions > Institut National de la Recherche Agronomique - INRA (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Other partners > Université Claude Bernard-Lyon I - UCBL (FRANCE)
Laboratory name:
Deposited On:04 Mar 2014 16:07

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