Flower strips are vital for supporting biodiversity and pollinators in agricultural landscapes. EXPBIO partners collaborate on research comparing regional seed mixtures across the North Sea Region to identify the most effective solutions for local ecosystems.
Transformations in the European landscape have always been dynamic and radical, and there have been periods of relative stability between these periods of transformation (Renes 2008). The main drivers of landscape transformation are technological advances in agriculture, institutional changes and economy. However, post-war agricultural policies in the EU promoted the intensification of agriculture by promoting technical innovations that resulted in an increasing pressure on biodiversity. To reduce the pressure on biodiversity, flower strips have been introduced to provide food sources and habitats to pollinators in agricultural landscapes. Many different seed mixes for species rich flower strips exist, which leads to one of EXPBIO’s tasks: comparing regional seed mixtures from the North Sea region.
The establishment success of flower strips depends on the quality of the seed mixture. Native plant mixtures were more efficient than standard cultivar seed mixtures. This can be explained by local adaptation. Local adaptation refers to the higher reproductive success of plant populations in their home environment than that of introduced foreign plant populations. Plant populations can adapt to a multitude of abiotic and biotic factors such as climate conditions, soil conditions and herbivores. Different transplantation experiments have shown that local plant populations outperform transplanted plant. In Germany, 22 seed transfer zones were established for the management of locally collected wild plant seeds and their reintroduction to the corresponding region after propagation. The main reasons for this system are local adaptation to local environmental conditions, synchronized phenology, and the conservation of local genotypes.
EXPBIO uses two regional seed mixtures from Germany (Saaten-Zeller, seed transfer zones 1 and 7), a Swedish regional seed mixture (Pratensis), and a regional seed mixture from the Netherlands (Cruydt-Hoeck) that mimics the species composition of the German regional seed mixture from seed transfer zone 1 with Dutch seeds (grasses of German origin). Multiple experimental sites were installed in spring 2025 in Belgium, Germany, the Netherlands, and Sweden, where two to all of the seed mixtures used were sown either in spring or in fall. Regular vegetation surveys will be conducted until September 2027. Additionally, EXPBIO includes pollinator surveys to gather data on the preferences of local pollinators.
We expect that
1. Regional seed mixtures will establish better in their native environments than in non-native environments
2. Regional seed mixtures will be more resilient against invasion from not seeded plants (grasses, for example) than non-regional seed mixtures
3. Regional seed mixtures will offer more food sources for pollinators than non-regional seed mixtures during the vegetation period
4. Regional seed mixtures will attract more pollinators in their native environment than non-native regional seed mixtures