Research Repository

The effects of elevated atmospheric CO₂ on freshwater periphyton in a temperate stream

Brown, TRW and Low-Décarie, E and Pillsbury, RW and Fox, GA and Scott, KM (2017) 'The effects of elevated atmospheric CO₂ on freshwater periphyton in a temperate stream.' Hydrobiologia, 794 (1). 333 - 346. ISSN 0018-8158

Full text not available from this repository.


This study examines the effects of elevated CO 2 on the benthic biology of a temperate freshwater stream. We tested the hypotheses that elevated CO 2 would increase periphyton biomass, alter elemental composition, and change community composition by increasing the frequency of algal taxa most limited by CO 2 availability. Carbon dioxide was bubbled into reservoirs of stream water, increasing the ambient pCO 2 by approximately 1100 ppm. The CO 2 -enriched water then flowed into artificial stream channels. Ceramic tiles were placed into the channels to allow for periphyton colonization. Dissolved inorganic carbon increased and pH decreased with added CO 2 . Measurements of biological parameters including periphyton biomass, algal C:N:P ratios, and community composition suggest that the periphyton were unaffected by the changes in stream water chemistry. We infer that rising atmospheric CO 2 will impact stream water chemistry but that periphyton may not be the first to respond to these changes. Impacts to alkaline freshwater streams from elevated CO 2 initially may be due to changes to terrestrial inputs that affect microbial decomposition and grazer activity, rather than through increases in periphyton carbon fixation. However, environmental characteristics of freshwater systems vary considerably, and additional studies are needed for accurate predictive modeling and monitoring of the effects of increasing atmospheric CO 2 on freshwater streams.

Item Type: Article
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Science and Health > Biological Sciences, School of
Depositing User: Elements
Date Deposited: 08 Sep 2017 11:41
Last Modified: 15 Nov 2018 18:33

Actions (login required)

View Item View Item