Soils are a major source of greenhouse gases on a global scale, with emissions resulting from natural processes such as microbial and root respiration, contributing to CO2 emissions, as well as other microbial processes contributing to CH4 and N2O emissions. However, anthropogenic emissions can disrupt these natural processes, leading to imbalances in greenhouse gas fluxes and influencing the trajectory of climate change. The aim of the project is to investigate the effects of atmospheric CO2 enrichment on greenhouse gas fluxes from soil, within a mature oak forest. These measurements will build on data that has already been gathered over the last eight years of CO2 fumigation at BIFoR-FACE. The research will also involve partitioning of heterotrophic and autotrophic soil respiration, as well as developing a new method for measuring root respiration in situ. Root samples taken after in situ root respiration measurements will be analysed for mycorrhizal fungal content, to gain insight into their role in soil respiration.