Impact on nature and the environment and compensatory measures
Like any construction project that takes up large areas of land, the construction of the European XFEL has had an impact on the environment in areas that affect humans, animals, plants and the landscape in general. In order to minimise these impacts as far as possible, extensive measures are aimed at avoiding, mitigating or compensating for these impacts.
For example, the construction work for the European XFEL was carried out in such a way that high-quality structures such as large trees, hedgerows or other semi-natural woodland are preserved as far as possible. This significantly minimises the impact on animals and plants as well as on the soil and landscape.
In addition, European XFEL compensated for the unavoidable impact on nature and the landscape well in excess of the requirements of nature conservation legislation. The compensatory measures include the renaturalisation of the creek Düpenau, the campus and the surrounding area with plantings, near-natural green spaces, hedges, groups of trees and natural areas.
In addition, European XFEL has planted native tree and shrub species such as silver birch, copper beech, ash and English oak, which provide nesting opportunities for various bird species, making the surroundings of one of the world's leading research facilities an attractive location for local nature.
Renaturalisation of the Düpenau lowlands
A central element of the compensation measures is the large-scale renaturation of the Düpenau creek on the Schenefeld site and in the surrounding area. European XFEL financed this renaturalisation work and was responsible for implementing half of the measures in close cooperation with the town of Schenefeld and the state of Schleswig-Holstein, while the other half was coordinated by the city of Hamburg.
As part of these measures, European XFEL has renaturalised more than one kilometre of the watercourse and extended it by meandering it. In the largely wood-free lowlands of the brook, a variety of basins with flattened banks, wetlands and a reedbed area now support a wide range of species. Frogs, sticklebacks and many other animal and plant species find a protected habitat here. At the edges of the flooded area, an alder and ash riparian forest is being created, which is transitioning into mixed oak forest in the higher areas. Subway profiles allow the Düpenau and wildlife to cross the site.
As a result of the removal of topsoil from some of the renaturalised areas and the creation of nature-friendly water bodies and dune structures. There are several territories of marsh warbler and stonechat. Thanks to the marsh warbler, the cuckoo can also be heard again in the Osdorfer Feldmark. Whinchats, bluethroats, snipe and woodcock have also been observed in the area during migration and wintering periods.
Mammals have also found a refuge along the Düpenau. These include roe deer, brown hare, fox and badger.
Of course, many insects have also colonised the area. These range from lynx flies of the genus Cliorismia, which specialise in sandy, shrub-covered riparian landscapes, to butterflies such as the brown blue and various meadow butterflies and dragonflies, of which an extraordinary variety of species populate the ponds and the Düpenau. The Fauna and flora habitat (see FFH) species Aeshna viridis was found several times in the ponds with crab claw vegetation. Somatochlora maculata and Ceriagrion tenellum were found. All native damselflies are present (Chalcolestes viridis, Lestes barbarus, Lestes dryas, Lestes sponsa, Lestes virens, Sympecma fusca) There is Aeshna affinis, the recently increasing Aeshna isoceles and Crocothemis erythraea are also present. Leucorrhinia pectoralis has even been sighted several times. The presence of orchids can be considered a botanical speciality.
Creation of near-natural copses, forest development, tree planting and rows of trees
Dense and tall trees typical of the landscape were planted along the edges of the site, and a meadow orchard with 15 trees was created. There are also trees along the connecting roads, in the car park area and in the built-up area. To the south-east of the Schenefeld research campus, a forest-like planting was created.
Creation of hedgerows
Knicks (hedgerows) are home to many plant species, including black elder, common viburnum, blackthorn, hazel, dog rose, willow, aspen, hawthorn and sycamore. Many bird species such as bullfinches, whitethroats, stonechats, Bohemian waxwing, and yellow warblers find breeding grounds in the trees and bushes of the hedgerows, while the flowering plants in the hedges provide food for bees and other insects.
As part of the compensation measures, European XFEL has planted new hedgerows in the Feldmark.
For example, European XFEL has had a 360-metre-long double kink created along the hiking and service path on the south-western edge of the site. A further 570 metres of knick were created on land provided by the town of Schenefeld on Holtkamp and Aneken roads.
Planting of green fences
The fences around the company premises should be as opaque as possible with predominantly evergreen climbing plants.
Creation of extensively maintained meadows and succession areas with low wood cover
The green areas on the company premises are mowed at different times. As part of natural processes, a mosaic of areas and islands of native trees and shrubs is created.
As a result of the extensive construction work, the eutrophic topsoil was removed from many areas, revealing leaner parts of the deeper soil layers. One particularly successful measure was the use of excavated soil from building pits to model an undulating area with pools. The relatively lean areas were sown with various seed mixtures, including regional meadow flower mixtures. The mixture of naturally occurring species and the seeds has resulted in a diverse and flower-rich meadow flora. Various insect species have colonised the areas. These include many meadow butterflies and rare species such as the Glanville fritillary and the swallowtail. The rather sandy soil also provides ideal nesting conditions for various ground-nesting hymenoptera. These include sand bees, leafcutter bees, digger wasps, path wasps and many more. The number of newly created ponds has continued to grow in recent years and the damselfly Ischnura pumilio, which specialises in young water bodies, has also settled here.
Bird and bat protection
Under expert supervision of the German Nature And Biodiversity Conservation Union (NABU), nesting aids attached to masts, buildings and trees offer numerous bird species and bats the opportunity to raise their young. Kestrels, jackdaws, sparrows, black redstarts, swifts and tits breed on the site. There is also a winter and three summer bat caves.
Insect protection
Honey and wild bees
European XFEL honey is produced twice a year in collaboration with local beekeepers. It bears the name ‘Beetime’ in reference to the researchers' beam time.
Wild bees love the elongated hills to the east of the main building, which are modelled on the tunnels of the X-ray laser, as a nesting aid.
The entire site offers bees a rich variety of flowering plants in the wild meadows and along the Düpenau.
