Abstract


EFFECTS OF TEMPERATURE ON ENERGY AND ELEMENT STORAGE IN STREAM ECOSYSTEMS

Anthropogenic activities are increasing global temperatures with uncertain and potentially large effects on ecosystem processes. Lotic ecosystems store, transform, and transport large amounts of energy and materials, and patterns of storage and flux within biotic and abiotic pools can alter food web dynamics and element cycling. To explore the influence of temperature on patterns of energy and element storage in streams, we quantified biomass and stoichiometry of benthic organic matter seasonally in geothermally-influenced streams that vary widely in temperature (5-30°C), but not dissolved chemistry. Coarse benthic organic matter (CBOM) biomass was unrelated to temperature–both the coldest and warmest streams showed similar patterns in total CBOM. However, CBOM varied widely across streams and seasons, suggesting other factors may interact to determine organic matter storage. Similarly, total nitrogen and carbon storage did not differ between the warmest and coldest streams. However, we observed significantly higher C:N ratios (24 vs. 18) of biomass-weighted CBOM pools in the warmest versus the coldest stream, suggesting that long-term warming and other undetermined factors may obscure obvious relationships between temperature and element storage in acclimated communities.

Authors

Junker, J. R., Montana State University, USA, james.junker@msu.montana.edu

Cross, W. F., Montana State University, USA, wyatt.cross@montana.edu

Benstead, J. P., University of Alabama, USA, jbenstead@as.ua.edu

Huryn, A. D., University of Alabama, USA, huryn@bama.ua.edu

Hood, J. M., Montana State University, USA, hoodx008@umn.edu

Nelson, D., University of Alabama, USA, dnelson12@crimson.ua.edu

Gíslason, G. M., University of Iceland, Iceland, gmg@hi.is

Ólafsson, J. S., Institute of Freshwater Fisheries, Iceland, jsol@veidimal.is

Details

Oral presentation

Session #:011
Date: 5/20/2014
Time: 10:30
Location: D 135 - 136

Presentation is given by student: Yes