Ecological assessment of groundwater ecosystems disturbed by recharge systems using organic matter quality, biofilm characteristics and bacterial diversity
2020
Voisin, Jérémy | Cournoyer, B. | Marjolet, L. | Vienney, Antonin | Mermillod-Blondin, Florian | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS) | Region Auvergne-Rhone-AlpesRegion Bourgogne-Franche-ComteRegion Hauts-de-FranceRegion Nouvelle-AquitaineAgence de l'Eau Rhone-Mediterranee-Corse French national research program for environmental and occupational health of Anses under the terms of project "Iouqmer" EST 2016/1/120Lyon Metropole | ANR-16-CE32-0006,FROG,Réponses fonctionnelles des aquifères souterrains aux pratiques d'infiltration en milieu urbain(2016)
International audience
Mostrar más [+] Menos [-]Inglés. Recharge of aquifers by urban stormwater may trigger significant ecological changes that can be detrimental to the biodiversity and functioning of groundwater ecosystems. Here, the effects of aquifer recharge (AR) on three levels of parameters were investigated: dissolved organic carbon (DOC) quantity and quality, global biofilm characteristics, and diversity changes of bacterial communities. As DOC enrichment by AR can be mitigated by vadose zone (VZ) thickness, three AR sites with thin VZ (< 3 m) and three sites with thick VZ (> 10 m) were selected. For each AR site, clay beads were incubated over a 10-day-long rainy period through wells in recharged and non-recharged groundwaters. Total proteins, dehydrogenase, and hydrolytic activities were monitored from clay beads to assess biofilm development. Bacterial richness on beads was estimated by 16S rRNA-based metabarcoding. AR was found to significantly increase DOC and biodegradable DOC (BDOC) concentrations, biofilm development, and bacterial richness especially in sites with thin VZ. VZ thickness was inversely related to microbial growth indicators and bacterial richness in groundwater, through a control of DOC availability. The proportion of Bacteroidetes 16S rRNA gene reads was higher in recharged groundwater than in non-recharged groundwater, suggesting that this phylum could be used as an indicator of DOC enrichment associated with AR. Quantitative PCR assays for Bacteroides DNA confirmed these trends and showed an enrichment of this bacterial group in DOC-rich aquifer waters. The positive linear relationships between BDOC concentrations and biofilm variables highlighted a strong C-limitation of groundwater impacting bacterial species sorting and activity.
Mostrar más [+] Menos [-]Información bibliográfica
Este registro bibliográfico ha sido proporcionado por Institut national de la recherche agronomique