Philipp Semenchuk Elisabeth Cooper Bo Elberling University of Tromsø, Arctic and Marine Biology University Center in Svalbard (UNIS) University of Copenhagen, Center of Permafrost (CENPERM) 23 May 2013 Ecosystem respiration patterns in the high Arctic are subject to change CO 2

2 Ecosystem respiration background Implications on global climate This presentation focuses on how global warming can change natural CO 2 emissions from Arctic tundra Temperature changes and respiration

3 CO2 emissions can be increased with warming Ecosystem respiration is mainly dependent on temperature Temperature Respiration

4 Better and more substrate  more respiration Ecosystem respiration is also dependent on substrate (=food for microorganisms)

5 Microbes are picky eaters: best substrates disappear quickly, worst substrates slowly Interaction with temperature. Not only food, but all biological material!

The Arctic is cold, but warming up

7 Winter soil temperatures change with snow thickness Fences increase snow depth Snow insulates soil

8 Best substrates are used up after 5 years of warm winters Temperature Respiration Date

9 Increased CO2 production during warmer winters could influence global CO2 concentrations ~20% of worlds C reserves

10 Microbes are picky eaters! However, tundra is a huge fridge (~20% worlds carbon)… Questions? In conclusion, increased winter temperatures might change whole year ecosystem respiration patterns in the Arctic