To improve the current understanding of the interplay between soil aeration and physical sediment/soil properties, fibre-optic measurements of oxygen in soil gas will be carried out at La Raya del Corte/Sabinar del Ojillo en dune sediments and Los Caracoles located in the marismas. The obtained analysis will completed by data of the measurement stations in the vicinity and by measurements of moisture, physical sediment properties and temperature within the framework of the ICTS-project 40/2009 carried out by IGME. Results of this project will provide insight into the dependence of soil aeration on physical soil conditions which is crucial to understand root growth and microbiological processes in the soil. Hence, the project adds fundamental knowledge of environmental processes related to gas transfer at the soil-atmosphere interface and will fundamentally contribute to the optimization of management strategies to protect the flora of the Doñana National Park.