Training in multi-scale approaches to understanding carbon dynamics in Arctic and upland systems

A network of Marie Curie host fellowships for Early Stage Research Training

Why MultiArc?

Image 3Upland and Arctic ecosystems contain a considerable store of carbon: tundra systems alone contain 11% of the world’s soil carbon pool. There is much concern, therefore, regarding the impacts of climate change on the capacity of these systems to store carbon. Indeed, tundra soils in Alaska have already changed from being a carbon sink to a carbon source, thus the future carbon balance for Arctic ecosystems remains unclear since these systems may have the capacity to switch between sources to sinks depending on the extent to which (micro)climatic, atmospheric and soil factors impact on productivity. Concern for such systems has heightened since climatic warming is predicted to be greatest at high latitudes, with the Arctic predicted to experience a 3oC average temperature increase by 2080. Understanding the processes that drive C dynamics within these systems is therefore of major importance to the global carbon cycle and feedback to climatic warming. Additionally, we currently lack sufficient knowledge to understand how the drivers of systems C dynamics scale up and how key components of the carbon cycle interact at different scales. Further, there is much need to understand these processes within systems of contrasting carbon stocks and ecosystem type, particularly given that much of the change in carbon dynamics within northern systems may be driven by the northward migration of more productive vegetation types.


Key Scientific Questions

The biogeochemistry of carbon in Arctic and upland systems is a poorly understood aspect of carbon cycling in the northern hemisphere. In particular, the focus has generally been on C-cycling within only small parts of these systems and as such we lack proper understanding of how plant and soil processes drive ecosystem and catchment-scale carbon dynamics. Furthermore, the best studies components within these systems are those characterised by significant organic carbon pools – largely because these pools are sensitive to anthropogenic disturbance (such as acid deposition or wetland drainage, climatic warming, permafrost thawing, insect pest outbreaks). We therefore also lack knowledge of catchments that have yet to develop such large carbon stores – for example those undergoing the natural transition from glacial to non-glacial conditions. This transition will result in a change from predominantly inorganic to organic carbon transfer, but at rates that are virtually unknown. Comparison between contrasting points along this transition within a sub-Arctic system (Abisko Sweden), and with a well-developed upland system in the UK therefore offers the opportunity to:

(a) quantify carbon fluxes in catchments representing different stages of development from systems of low carbon storage to those with significant carbon pools;

(b) compare these carbon dynamics along multiple transitions (glacial - non-glacial / alpine - sub-alpine / sub-Arctic – upland);

(c) understand how “up-stream” components of carbon cycling (e.g. plant traits, microbial functioning, soil processes) drive downstream changes in the organic and inorganic carbon dynamics of catchments;

(d) provide a much needed understanding of their sensitivity to future environmental perturbations.

The Approach

The six fellows importantly cover a broad spectrum of scales and incorporate the major processes and drivers of system carbon dynamics. 5 fellowships will focus on particular components of both the Arctic and upland systems, while integration across scales will be driven by a sixth fellowship.


Updated May 2006