Freeze-thaw effects on greenhouse gas emission, investigated by on-line concentration and isotope analyses

Main area:Ecology
 
Target group:Biology, Biochemistry
 
Educational level:Masters, Bachelor
 
Project description:

There is global concern that greenhouse gas emissions are affecting climate. Carbon dioxide and methane are the two most important greenhouse gases in terms of climate change; however, there are still uncertainties about their release from soils, and the effect of different plant species on emission rates.

For instance, change in soil environments as freeze-thaw in autumn and spring, or dry-rewet following drought and rainfall events may affect the release, and these events may become more important as climate is changing. By using novel, advanced equipment for online measurements of CO2 and CH4 and their isotopes, we are now able to measure the effects of ongoing changes in environmental conditions, by exposing mini-ecosystems collected from subarctic and temperate ecosystems to a range of environmental conditions (frequently changed temperature or moisture conditions) in growth chambers and sampling the air from these mini-ecosystems.

The aim of the work would be to clarify how environmental changes may affect CO2 and CH4 emission from soil and through plants, also using isotopic analysis on-line.

The project could involve mini-ecosystems from wet tundra in the subarctic and from similar but more warm temperate ecosystems, and could focus on growth chamber and lab experiments, but could also involve a field component.

You will get hands-on experience with plants, soils, simple and advanced analytical techniques and insight into effects of climate change on ecosystem- atmosphere interactions.

 
Methods used:On-line CO2 and CH4 measurements of air in mini-ecosystems in growth chamber, using isotopes in ecology, relating to soil and plant cover
 
Keywords:greenhouse gas emission, arctic and temperate ecosystems, influence of plant species, plant-microbe interactions, freeze-thaw and dry-rewet processes
 
Supervisor(s):  Anders Michelsen
 
Email:andersm@bio.ku.dk