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Oldenburg

In this pilot study, we evaluate the performance of regional and non-regional seed mixtures under local field conditions in the North Sea Region. Seed mixtures originating from Germany, the Netherlands, and Sweden are tested to observe their establishment and development during the EXPBIO project period. The regional reference for the Carl of Ossietzky Universität Oldenburg is Seed Transfer Zone 1 (UG1) provided by SaatenZeller. Non-regional mixtures include Seed Transfer Zone 7 (UG7) from SaatenZeller, an exact replica of the UG1 species composition using Dutch seed material from Cruydt-Hoeck, and a Swedish seed mixture supplied by Pratensis. By comparing these different seed origins, the pilot examines how provenance influences vegetation structure, establishment success, and species composition. The results will provide insights into the suitability of regional versus non-regional seed sources for ecological restoration in the North Sea Region.

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Location

The pilot is being carried out at two locations in Lower Saxony, Germany: Oldenburg and Neerstedt. In Oldenburg, three sites were selected, including two within the botanical garden of Carl von Ossietzky Universität Oldenburg and one at the municipal depot of the City of Oldenburg. These sites represent different local settings, such as variations in soil and surrounding land use. By working across these diverse locations, the pilot explores how seed mixtures develop under real-world conditions typical of the region.

Work planned/methods tested

Vegetation surveys will be carried out to assess the establishment success of the different seed mixtures. These surveys will record plant species presence, vegetation cover, and overall vegetation development over time. To complement these measurements, flower visitor observations will be conducted to evaluate ecological function. Observations will focus on a plant species included in all seed mixtures, common yarrow (Achillea millefolium L.), enabling standardized comparisons across sites. Flower-visiting insects will be recorded during flowering periods and identified to taxonomic groups where possible. 

Aim of work

The primary aim of this study is to investigate how successfully regional and non-regional seed mixtures establish under local conditions. In addition, the establishment performance of a regional seed mixture will be tested under non-regional conditions in Belgium. A further objective is to compare flower visitor activity in flowering meadows established with seed mixtures of different origins. By focusing on Achillea millefolium, pollinator visitation can be assessed consistently across all treatments. The study aims to determine whether regionally sourced seed mixtures support higher or more diverse flower visitor activity. Overall, the results will improve understanding of the ecological value of regionally adapted seed sources and inform biodiversity-oriented seed mixture selection.

Status right now

Flowering meadows were sown for the first time in spring 2025, however the establishment success was badly influenced by the drought in spring 2025. The first vegetation monitoring was performed by students of the Carl von Ossietzky Universität, which then was followed by a second sowing in autumn 2025 to improve establishment success. Additionally, the first flower visitor monitoring was performed which lead to an adjustment to the used methods. The pilot is in an early but promising stage