Temporal sampling complete in SOB4ES!
In November, SOB4ES partners from eight countries across Europe have completed the temporal soil biodiversity sampling. The samples will be used to reveal temporal trends alongside spatial soil dynamics and highlight soil biodiversity across major European land use types.
What is temporal sampling?
For this large-scale temporal study, samples were taken from the same sites during different seasons and at the same time over multiple years. The resulting temporal data can be analysed to reveal how different soil properties like soil moisture, and soil biodiversity, can vary between regions and over time. This data is crucial in monitoring soil health and restoring degraded European soils. The SOB4ES team has carried out five temporal sampling events, with an initial sampling in Fall 2023 and additional sampling events in Spring 2024, Summer 2024, Fall 2024, and Fall 2025. This sampling regime allows the comparison of data between seasons (Spring, Summer and Fall 2024) but also between years (2023, 2024 & 2025). All biological data will be assessed by molecular identifications, which will be validated against morphological identifications of soil organism species.
The eight partners from Belgium, Ireland, Spain, the Netherlands, Switzerland, Romania, Slovenia and Sweden collectively sampled 33 sites across arable lands, forests, grasslands, urban and wetland sites. Each partner sampled three plots per site, which amounted to 99 plots per time-point. In total 396 samples were taken across the whole temporal soil sampling campaign.
“We are processing the soil samples for environmental DNA to get a good idea of the temporal dynamics of the composition of microbiomes and soil fauna across arable fields, grasslands, forests, and other land use types”, says Giles Ross, SOB4ES researcher at NIOO-KNAW.
Novel monitoring protocols
Environmental DNA or eDNA is the genetic material collected from soil that can be used to monitor the distribution of organisms. “The eDNA that is analyzed by the SOB4ES project is increasingly used for biodiversity monitoring, however, its use without proper validation has methodological limitations”, says Maria Briones, coordinator of the SOB4ES project. “One advancement of SOB4ES is that we are able to validate eDNA by comparison with classic morphological species identification.”
After meeting this important milestone, we can now begin to assess soil biodiversity community structures and their responses to drivers and pressures over time. This information will improve soil health assessments across Europe and help to understand and predict the consequences of rapid changes in land use and land management practices. The temporal sampling will also provide an important framework on how to carry out measurements as needed for the EU Soil Monitoring Law, which has been approved recently and will be rolled out during the next years.
Together with the extensive spatial sampling of which all identifications now are completed, the temporal sampling campaign marks an important step forward in shedding a light on the dynamics of European soil biodiversity, which is information that will help designing the future European soil health monitoring program.
