2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/20/2019 | 12:00 PM - 12:15 PM | LIGHT VS. NUTRIENT EFFECTS OF DOM ON BENTHIC PRODUCTION IN NORTHERN LAKES | 150 DEF
LIGHT VS. NUTRIENT EFFECTS OF DOM ON BENTHIC PRODUCTION IN NORTHERN LAKES
Among lakes, observed hump-shaped relationships between gross primary production (GPP) and dissolved organic matter (DOM) are hypothesized to result from nutrient supply (positive relationship) and light absorption (negative relationship). To test these mechanisms, we used nutrient diffusing substrata (NDS) to examine benthic biofilm growth and type/strength of limitation among lakes along a DOM gradient. While we did not observe a clear relationship between biofilm growth and DOM in unamended controls, nutrient limitation differed along the gradient. At low DOM, we saw limitation by N alone, at moderate DOM there was primary limitation by N and secondary limitation by P, while at higher DOM light limitation superseded the effects of added nutrients. In four lakes, we incubated NDS at three depths to isolate effects of nutrient supply and light. In clearer lakes, chl-a in controls was consistently low, while in the darkest lake, shallow deployments had the highest chl-a. In contrast, we observed the largest responses to added N in shallow incubations of the clearest lakes. These results support the hypothesis of dual control of terrestrial DOM on GPP via nutrients and light, creating a nonlinear relationship between GPP and DOM.
- Algae
- Aquatic-terrestrial Linkage
- Nitrogen
Presentation:
This presentation has not yet been uploaded.
Handouts:
Handout is not Available
Transcripts:
CART transcripts are NOT YET available, but will be posted shortly after the conference
Presenters/Authors
Megan Fork
(), Cary Institute of Ecosystem Studies, forkm@caryinstitute.org;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Jan Karlsson
(), Umeå University, jan.p.karlsson@emg.umu.se;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Ryan Sponseller
(), Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden, ryan.sponseller@emg.umu.se;
ASHA DISCLOSURE:
Financial -
Nonfinancial -