Abstract


TOWARDS UNDERSTANDING SHORT- AND LONG-TERM RESPONSES TO WARMING USING A NATURAL GEOTHERMAL LABORATORY

A growing number of studies suggest that short- and long-term responses to climate warming may differ because of acclimation, adaptation, and time-lagged shifts in community structure. Predicting effects of warming thus requires studies that explicitly account for temporal scale. We are using a natural geothermal laboratory in Iceland to quantify how temperature (~5-30°C) affects the structure and function of stream ecosystems at three temporal scales: short-term channel experiments, a mid-term whole-stream warming experiment, and a natural gradient of 'temperature-acclimated' streams. Our initial results show three patterns. First, warming leads to increased gross primary production and ecosystem respiration at all scales, but temperature dependence is strongest in short-term experiments. Second, responses of primary producers to warming differ among temporal scales, with nitrogen fixers gaining dominance in short-term studies and acclimated streams, but not in the mid-term warming experiment. Third, invertebrate biomass in the mid-term warming experiment has declined, which is not consistent with patterns in the temperature-acclimated streams. Together, our preliminary results suggest that responses to warming may be scale-dependent, underscoring the need to better acknowledge temporal scale in climate warming research.

http://www.montana.edu/wcross/Cross_website/Home.html

Authors

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

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

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

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

Welter, J. R., St. Catherine University, USA, jrwelter@stkate.edu

Junker, J. R., Montana State University, USA, james.junker1@gmail.com

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

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

Johnson, P. W., University of Alabama, USA, pjohnson@eng.ua.edu

Gislason and Olafsson, G. J., University of Iceland, Institute of Freshwater Fisheries, Iceland

Details

Oral presentation

Session #:127 B
Date: 5/21/2014
Time: 15:00
Location: B 117 - 119

Presentation is given by student: No