Dr. Jens-Arne Subke visits the Cluster of Excellence from beginning of August until the end of December 2014. Dr. Subke is Senior Lecturer in ecosystem ecology at the University of Stirling (Scotland), and his expertise is the investigation of biogeochemical cycles in terrestrial ecosystems, with particular interest in the impact of changes in environmental conditions on exchange processes of greenhouse gases. He investigates interactions of plants and soil in processing carbon stored as organic matter, and the use of stable isotopes (e.g. 13C, 18O, 15N) in terrestrial ecology. He is hosted by Prof. Dr. Lars Kutzbach for the duration of his visit to the Universität Hamburg.

His current projects focus on the role of vegetation changes on organic soils in cold climates. One of his current projects investigates the role of hydrology on greenhouse gas fluxes from permafrost soils in the Canadian Arctic. Continued increases in temperature have caused an expansion of shrubs and trees into tundra regions, with direct implications for the way in which carbon is stored and cycled in the ecosystem. The project uses isotopic approaches to investigate changes in flowpaths of water and transport of dissolved forms of carbon following deeper thaw in summer as well as contrasting turnover of carbon between different shrub species. One of the projects strengths is the focus on linking hydrological processes with the carbon cycle, and modeling fluxes for larger scales. An additional project with fieldwork based in Sweden investigates the role of mycorrhizal fungi in the forest-tundra ecotone. Forest sites at the treeline have smaller carbon stocks, despite higher rates of CO2 fixation. A shift in the treeline can potentially mobilise carbon stored currently under tundra heath vegetation, releasing more CO2 to the atmosphere. The role of contrasting mycorrhizal fungi between forest and tundra vegetation is hypothesized to be critical to this transition.

The ‘Flows’ in the north of Scotland holds the largest expanse of blanket bog in Europe, and possibly world-wide. A large portion of the bog has been drained for forestry in past decades, a process that the Scottish government aims to reverse in order to restore carbon sequestration and storage. A large-scale restoration effort has begun, and Dr. Subke is part of a team investigating the short-, mid- and long-term impacts of the restoration work. Fluxes of CO2, methane and nitrous oxide as well as aqueous transport are measured at different scales and covering forest, transitional sites and pristine bog. Alongside these measurements, changes in biodiversity and water dynamics as important ecosystem services are also investigated.

Many of Dr. Subke’s research interests are well aligned with the work carried out in the CliSAP Research group of Dr. Lars Kutzbach and other working groups at the Institute of Soil Science. Apart from an exchange of ideas and mutual learning about techniques and approaches, the purpose of Dr. Subke’s visit is to create new research links with Dr. Kutzbach’s group with a view to develop joint research proposals. One initial aim is to set up a training network for Ph.D. students focusing on restored peatland sites, linking work in the blanket bogs of the Flows in Scotland with research carried out in the bog Himmelmoor near Hamburg as well as other restored peatland sites in Europe.

 

Email: jens-arne.subkedummy@stir.acdummy2.uk
Web: http://rms.stir.ac.uk/converis-stirling/person/10833

Currently: Institute of Soil Science, Room 505
Telephone: +49 (0)40 42838 2010