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Biofilm‐induced bioclogging produces sharp interfaces in hyporheic flow, redox conditions, and microbial community structure
Author(s) -
Caruso Alice,
Boano Fulvio,
Ridolfi Luca,
Chopp David L.,
Packman Aaron
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl073651
Subject(s) - hyporheic zone , biogeochemical cycle , microbial metabolism , nutrient , environmental chemistry , sediment , microbial population biology , biomass (ecology) , environmental science , autotroph , biofilm , microbial mat , microcosm , heterotroph , nitrogen cycle , ecology , nitrogen , chemistry , geology , surface water , biology , environmental engineering , bacteria , cyanobacteria , geomorphology , paleontology , organic chemistry
Riverbed sediments host important biogeochemical processes that play a key role in nutrient dynamics. Sedimentary nutrient transformations are mediated by bacteria in the form of attached biofilms. The influence of microbial metabolic activity on the hydrochemical conditions within the hyporheic zone is poorly understood. We present a hydrobiogeochemical model to assess how the growth of heterotrophic and autotrophic biomass affects the transport and transformation of dissolved nitrogen compounds in bed form‐induced hyporheic zones. Coupling between hyporheic exchange, nitrogen metabolism, and biomass growth leads to an equilibrium between permeability reduction and microbial metabolism that yields shallow hyporheic flows in a region with low permeability and high rates of microbial metabolism near the stream‐sediment interface. The results show that the bioclogging caused by microbial growth can constrain rates and patterns of hyporheic fluxes and microbial transformation rate in many streams.