Iceland

Predicting effects of climate warming on stream ecosystem structure and function

We are currently studying the influence of temperature and nutrient supply (i.e., nitrogen and phosphorus) on the structure and function of stream ecosystems in the Hengill region of Iceland. Streams in this area are variably warmed by geothermal heat, with mean temperatures ranging from 5°C to 30°C. Although temperatures are variable, stream solute chemistry is remarkably similar due to the indirect warming of groundwater. Thus, streams in this area provide a unique natural laboratory for examining interacting effects of climate warming and eutrophication on stream structure and function. 

We’re testing predictions about how food web dynamics and ecosystem processes will change with climate warming using two unifying frameworks - (1) biological stoichiometry and (2) metabolic theory of ecology. Because these frameworks are based on first principles (e.g., conservation of mass, thermodynamics), we expect our results to be generally applicable to other ecosystems.  

We have developed strong collaborations with our colleagues in Europe, and we are now able to accomplish much more as a larger team with complementary areas expertise.

The Team

• Wyatt Cross, Montana State University
• Jon Benstead, University of Alabama
• Alex Huryn, University of Alabama
• Jill Welter, St. Catherine University
• Gisli Mar Gislason, University of Iceland
• Jon Olafsson, Institute of Freshwater Fisheries, Iceland

International colleagues and collaborators

• Guy Woodward, Imperial College London
• Eoin O'Gormann, Imperial College London
• Benoit Demars, James Hutton Institute Scotland
• Nikolai Friberg, Aarhus University Denmark