Creation of two new sandariums

Anyone walking across the university campus these days, coming from the NWI and heading towards the Geo building, will see a wonderfully colourful flowering sandy area on their right, which, on closer inspection, is buzzing and humming with activity...

Sandariums are artificial or near-natural sandy areas that play an important role in promoting biodiversity. Many rare and specialised animal and plant species depend on open, sandy locations, which are hardly to be found anymore in intensively used cultivated landscapes. Two such sandariums were created on the University of Bayreuth campus this year, one in front of the GEO II building and one at the edge of the southern areas of the Ecological-Botanical Garden (ÖBG). The starting point was the intention to further promote measures to increase the attractiveness of the campus for endangered animal species. Ground-nesting wild bees, digger wasps and sand beetle species in particular need loose, dry and vegetation-poor sandy areas in order to reproduce successfully.

In the summer of 2024, the opportunity arose to spontaneously implement this long-cherished project. After the ‘Summer Feeling at the University Beach’ event on the campus roundabout, approximately 70 tonnes of sand were available, which, in the spirit of sustainability, could be recycled as sandariums and for the ÖBG's Mediterranean plant area. Together with Dr Andreas von Heßberg (Scientists for Future), we were able to draw on the wealth of experience of the ‘Die Summer e.V.’ initiative, which has already created various sandariums in the Bayreuth city area. The location was ultimately chosen to be one of the UBT's biodiversity areas, a meadow with light southern exposure in front of the Geo II building that receives sunlight all day long. Ideal for heat-loving animals and plants! At the same time, a sandarium was created at the southern edge of the ÖBG arboretum with a view of the southern areas.

The employees of Central Technology (ZT) volunteered their working hours and heavy equipment to excavate an area of approximately 100 square metres to a depth of 20 cm in November 2024. The sand (ideally unwashed, i.e. loess-containing, with a grain size of 0-2 mm) was stacked to a height of approximately 50 cm at the end of February 2025 by employees of the ÖBG, where it had been temporarily stored. In May 2025, the time had come: more than 20 volunteers from the geoecology and biology degree programmes and members of the university group of the Landesbund für Vogelschutz (LBV) helped to plant more than 150 small plants, most of which had been grown by the ÖBG's gardeners. These are drought-loving species such as round-leaved bellflower, common thyme, Carthusian pink, dyer's chamomile, meadow knapweed, meadow yarrow, meadow marguerite, yellow reseda and mountain sandbell. Not only do they provide nectar and pollen for pollinators, but they are also needed as food by specialised butterfly caterpillars. In addition, they attract many species of wild bees, which prefer to dig their nests in compacted sand near small plants. Incidentally, small sand gardens are also useful in your own garden:  in addition to their function as a habitat for ground-nesting insects, they do not need to be watered if planted appropriately, snails avoid the dry sand, and wild bees can be observed among the beautiful flowers in sunny weather.

The two sand pits at UBT not only actively contribute to the protection of endangered species, but also create an experiential space for students and staff on campus. They invite visitors to observe nature directly on campus and highlight ecological relationships. The specialised species communities that settle there can interact with other sandy areas currently being created by the city of Bayreuth in the ‘Green South of Bayreuth’, e.g. at Röhrensee or in the new Bürgerhain in Saas. Appropriate information boards will also raise awareness of biodiversity and sustainability in the future. Sandariums thus make a double contribution: they act as ecological stepping stones in urban areas and at the same time promote environmental education in society.

The newly created sandarium at the Geo building is located on one of currently 33 biodiversity areas (approx. 50,000 m²) on the UBT campus. The first of these areas, which are mowed only once a year to increase species diversity on campus, were designated in 2016. In the meantime, in cooperation with the Central Technical Services, the plant species diversity of the areas has been further increased by sowing species-rich native seed mixtures, the number of areas included in the programme has been expanded, and a maintenance concept, the so-called ‘insect-friendly mowing regime’, has been introduced and successfully implemented. Based on new scientific findings, the latter pursues a mosaic-like mowing approach to accommodate the highest possible number of species. A small portion of the areas (approx. 20%) are mowed in summer. The areas mowed in summer produce a second bloom, and the newly growing vegetation remains standing over the winter as an important structure and winter quarters for insects. The remaining areas (approx. 80%) are mowed with the usual autumn mowing and the mown material is removed to reduce the nutrient content of the areas.

Even though some of the biodiversity areas are disappearing again due to the construction of new buildings on campus, ecological aspects now form an important component in the implementation of green space design projects by the ZT at the UBT.