Bista , Deepesh Raj , Heckathorn, Scott , Bridgeman, Thomas .
Effect of Increased Temperature and Nitrogen on Non-N-fixing vs. N-fixing Cyanobacteria in Western Lake Erie: Implications for Competition, and Climate change. .
Harmful algal blooms(HABs) in freshwater ecosystems, especially of cyanobacterial species, are becoming more frequent and expanding geographically, threatening some of the world's largest and most-important water bodies, including Lake Erie in North America. HABs are the result of complex and synergistic environmental factors, though N or P eutrophication is a leading cause of HABs. With global mean temperatures expected to increase an additional 2-5oC by 2100, cyanobacterial blooms are predicted to increase even more, given their typically high temperature optimum for growth. We are investigating how increases in temperature (global warming) and nitrogen (eutrophication), singly or incombination, affect the growth, food quality of cyanobacteria, and in turn, competition between N-fixing and non-N-fixing cyanoHABs. Both algal community samples collected from Lake Erie, and isolated N-fixing and non-N-fixing cyanobacterial species, were cultured at 20/25/30oC and 5, 50, 150, and 250 mM N, and then analyzed for growth and content of total protein,lipids, and non-structural carbohydrates (TNC). Both temperature and N affected algae and there were temperature x N interactions. For example, cyanobacteria (but not green algae) growth increased with both temperature and N, especially from 25-to-30oC, but N increased cyanobacterial growth primarily only at 30oC. Temperature and N effects on protein, lipids, and TNC will affect food quality of algae for herbivores, and hence, herbivory will likely be impacted by N x temperature interactions too.
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1 - University of Toledo, Environmental Sciences, 2801 Bancroft St MS 620, Toledo, Oh, 43606, United States
2 - University Of Toledo, EARTH, ECOLOGICAL & ENVIRONMENTAL SCIENCES, MS 604, 2801 W. Bancroft, TOLEDO, OH, 43606-3390, USA
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM