Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1002/lno.11927
Licence creative commons licence
Title (Primary) Hydraulic and biological controls of biofilm nitrogen uptake in gravel-bed streams
Author Anlanger, C.; Risse-Buhl, U.; von Schiller, D.; Noss, C.; Weitere, M.; Lorke, A.
Source Titel Limnology and Oceanography
Year 2021
Department FLOEK
Volume 66
Issue 11
Page From 3887
Page To 3900
Language englisch
Topic T5 Future Landscapes
Abstract Epibenthic biofilms are important in regulating nitrogen (N) fluxes in stream ecosystems. The efficiency of the regulation is controlled by hydraulic and biological processes and their interactions. However, knowledge on the underlying physical and biological processes, their controlling parameters, and interactions in stream ecosystems is still limited. To analyze the relative importance of hydraulic and biological controls on biofilm N uptake, we measured turbulence, biofilm N uptake using a stable isotope tracer, and biofilm biomass in two gravel-bed streams with contrasting nutrient concentrations for two seasons. We found high within-stream variability in biofilm areal N uptake and uptake velocity, which exceeded variability between streams and seasons by 60% and 30%, respectively. Sixty-four percent of the within-stream variability in uptake velocity was explained by hydraulic mass transfer and biofilm characteristics, which were described in terms of the turbulent dissipation rate and the biofilm biomass, respectively. We show that surface renewal theory based on scales of the smallest turbulent eddies can be used to estimate transfer velocities at the sediment–water interface and can be extrapolated to larger scales by spatial averaging. Our results improved the mechanistic understanding of the processes regulating biofilm N uptake at small scale which contributes to the understanding of ecosystem functioning in low-order streams and supports upscaling to larger spatiotemporal scales along stream networks.
Persistent UFZ Identifier
Anlanger, C., Risse-Buhl, U., von Schiller, D., Noss, C., Weitere, M., Lorke, A. (2021):
Hydraulic and biological controls of biofilm nitrogen uptake in gravel-bed streams
Limnol. Oceanogr. 66 (11), 3887 - 3900 10.1002/lno.11927