Journal
SCIENCE OF THE TOTAL ENVIRONMENT
Volume 806, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.scitotenv.2021.150505
Keywords
Benthic algae; Nutrient diffusion substrates; Current velocity; Eutrophication; Canopy coverage
Categories
Funding
- Aarhus University
- University of the Chinese Academy of Sciences
- University of the Republic, Uruguay
- TuBITAK, BIDEB 2232 program [118C250]
- Doctoral INPhINIT- INCOMING program, from la Caixa Foundation [LCF/BQ/DI20/11780004, 100010434]
- Sino-Danish Center
Ask authors/readers for more resources
The research highlights the significant impact of light and nutrient availability on the responses of periphyton biomass and composition to discharge. Nutrient enrichment and full light conditions increase periphyton biomass and affect its composition.
Climate-induced changes in precipitation and land-use intensification affect the discharge of streams worldwide, which, together with eutrophication and loss of riparian canopy, can affect periphyton biomass and composition, and therefore, ultimately the stream functioning. We investigated the responses of periphyton biomass and life-forms (i.e., high profile, low profile and motile) to these changes applying an experimental approach by modulating nutrients (nutrient diffusion substrates enriched with 0.5 M NH4NO3 + 0.031 M KH2PO4 and without nutrient enrichment) and light availability (50% shade and full light) along a gradient in discharge ranging from 0.46 to 3.89 L/s (0.7 to 6.5 cm/s) in twelve large-sized (12- m long) outdoor flumes resembling lowland streams. We also analysed the potential effects of other environmental variables including macroinvertebrates on the responses of periphyton to discharge, nutrients, and light. Light and nutrient availability drastically affected periphyton biomass and composition responses to discharge. Periphyton biomass decreased with increasing discharge when shaded but this did not happen when exposed to full light. Under full light conditions, nutrient enrichment mediated an increase in the periphyton biomass with increasing discharge, possibly reflecting an increased metabolism, but this did not happen under non-enriched conditions. Enrichment further affected the compositional responses of periphyton to discharge, with an increase in the biomass of motile, fast growing, small-sized flagellated at low discharge conditions, and mitigating a loss of high profile periphyton under higher discharges. Light did not affect periphyton composition, and the abundance or feeding-group composition of the macroinvertebrates did not affect biomass or composition of the periphyton either. Our results suggest that nutrient enrichment and light play an important synergistic role in the responses of the periphyton biomass and composition to discharge and emphasize the relevance of riparian canopy conservation and eutrophication control to avoid periphyton growth under increased discharge scenarios in small lowland streams. (C) 2021 Published by Elsevier B.V.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available