Is the terrestrial sink of green house gases going to change? Measuring the oxidative ratio of scandinavian peatlands

To estimate the relative global sinks of greenhouse gases, the Intergovernmental Panel on Climate Change (IPCC, 2007) consider the relative changes of oxygen and carbon dioxide (CO₂) concentrations in the atmosphere. The relative exchange of oxygen and CO₂ between global stores is referred to as the oxidative ratio (OR). Current estimations suggest that a little under a third of anthropogenic carbon emissions are captured by the terrestrial biosphere. However, the exchange with the terrestrial biosphere is poorly constrained and we do not know how it will change over time. This uncertainty leads to two research questions: 
i) What is the magnitude of the OR for the terrestrial biosphere?
ii) How does OR change with time?
The best places to test for changes in OR would be where carbon storage within the terrestrial biosphere is rapidly changing. The boreal peatlands are under threat from the northward expansion of climatic zones that means that not only is the southern fringe of the peatlands being lost but there is a northward retreat of the tundra. Therefore, we propose a transect through the northern hemisphere peatlands sampling peatland soils from a southern edge in southern Sweden through sub-boreal and boreal forests, and into the Arctic peatlands in northern Norway.

Summary Aims:
• To measure the magnitude and change of the oxidative ratio (OR) of the globe’s most important terrestrial reserve of carbon.
• The project will measure oxidative ratio of soils and biomass along a transect spanning the northern fringe of European peatlands.

The study showed that although there was no difference between soil orders, there was a significant effect due to location with OR increasing from 1.03 at the southernmost location to 1.09 in the northernmost location; this increase is independent of soil order or type of organic matter. The pattern of post hoc differences in the OR with latitude suggests that the increase in OR is correlated with the northern limit of arable agriculture. The study suggests that the combined effects of climate and land use change could lead to a decrease in terrestrial organic matter OR and an increase in its oxidation state