World’s soils contain more carbon than atmosphere and biosphere combined. Learning to control the processes in soil responsible for 'locking carbon away' for long-term storage has thus potential to counterbalance the excessive CO2 emissions and mitigate effects of the global climate change. Soil aggregate formation has been recognized to play a major role in physical soil carbon stabilization, but the responsible processes are not well understood. Thus, the aim of my postdoc project is to study dynamic processes of soil aggregation at micro- to nano-scale by means of different spectroscopic techniques including synchrotron radiation based X-ray microspectroscopy at large national research centers such as MAX IV or Canadian Light Source. The major interest is to study the role of microorganisms or, more specifically, microbial necromass and fungal exudates, to the aggregate formation. For higher control of the processes we perform experiments within microfluidic chips - micro-spatially designed growth habitats for soil microbes, in which we manipulate physical structure and chemical availability of nutrients at micrometer scale. Ultimately, uncovering the mechanisms of physical carbon stabilization will be crucial for identification of soil cultivation techniques which foster this process, and to be able to increase the carbon sink potential of our soils by convincing agriculture and forestry policy makers.
People: Milda Pucetaite, Pelle Ohlsson, Edith Hammer