Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E79

The effects of environmental temperature and thermal adaptation on predator-prey interactions: a novel approach using a geothermal system

Louise Archer (1,2), Bruno Gallo (1), Rebecca L. Kordas (1), Björn C. Rall (3), Esra Sohlström (4), Eoin J. O'Gorman (1)

1. Imperial College London, 2. University College Cork, Ireland, 3. German Centre for Integrative Biodiversity Research (iDiv), 4. Georg-August-University, Göttingen

Kynnir / Presenter: Louise Archer

Tengiliður / Corresponding author: Louise Archer (louise.archer14@imperial.ac.uk)

The predicted rise in global surface temperatures in this century is expected to have severe consequences for the structure and functioning of ecosystems. Predator-prey interactions strongly depend on environmental temperature, with warming likely to destabilise long-term community dynamics as a result. Thermal adaptation offers a potential mechanism for organisms to persist despite environmental warming, however its role in moderating the effects of warming on predator-prey interactions is poorly understood. This study advances our knowledge of how thermal adaptation alters the feeding response of predators by utilising the natural temperature gradient of geothermally heated streams to measure the functional response of thermally acclimated predators with increasing environmental temperatures. The Hengill geothermal system acts as a natural laboratory, allowing a novel in situ experimental design in which thermally adapted organisms are manipulated across a temperature gradient, while retaining the complexities of a natural system. Time taken to handle prey decreases with environmental warming, with an associated increase in maximum feeding rate. Capture rates increase with warming, with variation in the temperature dependence of both handling time and capture rate according to predator foraging strategy. No effect of thermal adaptation on the functional response is seen. The temperature dependence of feeding interactions supports predictions that warming poses a major threat to community stability. Here we show acclimation to warmer temperatures may not be sufficient to dampen the effects of global warming, while also demonstrating the utility of geothermal systems for temperature manipulation experiments.