Abstract


WARMING ALTERS THE FUNCTIONAL COMPOSITION AND STOICHIOMETRY OF AQUATIC BIOFILMS

The effects of climate warming on aquatic ecosystem structure and function are mediated by transient changes in organismal physiologies and shifts in community structure. While much is known about physiological responses to temperature, we know comparatively little about how physiological responses will modulate ecosystem function when coupled with shifts in community structure. In our study we examined the effects of temperature on the structure and function of aquatic biofilms in a streamside channel experiment (treatment means = 6, 11, 16, 21, and 28oC). We found strong positive effects of temperature on organic matter biomass, chlorophyll a, and rates of key ecosystem processes (GPP, ER, N uptake), which changed through time with biofilm succession. Warming produced counterintuitive shifts in biofilm stoichiometry, with reduced C:N and C:P ratios, likely driven by increased dominance of nutrient-rich cyanobacteria. Our results suggest that climate warming influences the role stream biofilms play in shaping carbon and nutrient cycles via interactions between direct effects on organismal physiology and changes in community structure.

Authors

Williamson, T. J., Montana State University , USA, tanner.williamson@gmail.com

Cross, W. F., Montana State University , USA

Welter, J. R., St. Catherine's University , USA

Benstead, J. P., University of Alabama , USA

Hood, J. M., Montana State University , USA

Huryn, A. D., University of Alabama, USA

Johnson , P. W., University of Alabama, USA

Details

Oral presentation

Session #:139 A
Date: 5/22/2014
Time: 11:15
Location: D 135 - 136

Presentation is given by student: Yes