Soil structure drives dissolved organic carbon loss from peat soils under variable land use and climate stress – PEAT-STRUCTURE

• Applicant: Dr. Haojie Liu
• Subject Area: Soil Sciences
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 513663327

Artificial drainage threatens peatlands as the largest terrestrial carbon store. While gaseous carbon emissions are under scrutiny for decades, the release of dissolved organic carbon (DOC) remains under-investigated. The soil structure controls water flow and solute transport in peat; it is, however, unclear how various flow domains (macropore flow pathway or the soil matrix) regulate DOC production and flux. The aim of the proposed research is to quantify DOC release from peat soils as a function of soil structure and resulting flux field. Soil samples will be collected from peatland sites under diverging management (near-natural, drained, rewetted). Samples will be subjected to solute transport experiments employing a newly developed set-up with a multi-port sample collection system to distinguish between flow domains. Soil physical properties as well as geochemical transformation processes are influenced by weather conditions especially temperature and rainfall amplitudes. Therefore, the impact of freezing-thawing as well as drying-wetting cycles on DOC release will be studied to better understand the interrelation between soil structure dynamic (CT-scans) and carbon turnover. The planned work is based on extensive preparatory work ensuring a smooth operation and overall success of the project.

• DFG Programme: Research Grants