Species rich and colorful meadows have been established in Central Europe over many centuries, as they have been consistently used for the production of hay and straw. The species diversity is at its highest when mowed once or twice per year with no or little fertilizing. Due to increasingly intense usage and land conversion, such extensively used, ecologically valuable habitats have actually become very rare. Three grassland areas in the Botanical Garden are cultivated accordingly to preserve rare plant communities for teaching and research purposes on sufficiently large areas. Selected threatened species from the Ex-Situ Conservation Program are also propagated at these sites.
Alkaline spring water mire
The species composition of the wet meadow, which spontaneously cropped at the source of the Kayen Mill Creek, is characterized by year-round soaking from constantly flowing groundwater and late mowing in the year. In some parts, this wet meadow is only moderately nutrient-rich, making the perfect conditions for a brown moss-sedge reed community. This is where the uppermost source flows from the Kayen Mill Creek, a natural stream that flows through the Botanical Garden. The species composition is characterized by year-round soaking with alkaline groundwater and two late mowing cycles per year. In May and June, large populations of the western marsh orchid (Dactylorhiza majalis) dominate the aspect of this habitat, while the buckbean (Menyanthes trifoliata) dominates the more nutrient-poor areas. A few weeks later, the inflorescences of the marsh helleborine (Epipactis palustris) and, in the more nutrient-rich part, wild angelica (Angelica sylvestris) color the area. Though it belongs to the community in small amounts, common reed (Phragmites australis) is removed on a yearly basis to allow the more valuable wildflowers and orchids to flourish.
Nutrient-rich wet meadow
As a counterpart to both the oligotrophic sandy dry grassland and the spring water mire, this wet meadow is characterized by permanent soil moisture due to its proximity to groundwater, high nutrient richness and more shady, humid location. In April, a large population of snake’s head fritillary, also called chess flower (Fritillaria meleagris), dominates the scene for about ten days before taller grasses and perennials take over the area, among them marsh marigold (Caltha palustris), marsh hawk’s-beard (Crepis paludosa), water avens (Geum rivale), cabbage thistle (Cirsium oleraceum), meadowsweet (Filipendula ulmaria) and wood club-rush (Scirpus sylvaticus). In summer, the inflorescences of the common spotted orchid (Dactylorhiza fuchsii) and the common twayblade (Listera ovata) can also be found. Due to the abundant supply of nutrients, this vigorous meadow requires more frequent maintenance and regulation measures right into autumn.
Sandy dry grassland
The landscape in north-eastern Germany is characterized by extensive moraine deposits from the last ice age. Among them are numerous sandy hills, one of which is also in the Botanical Garden. The water retention capacity and nutrient supply are low, the soils only barely developed. In a sun-exposed southern location, a meagre grassland develops which is populated by adapted small-scale specialists. Since the economic utility value of such areas is low, this habitat, which was formerly common in the landscape, has mostly been covered with buildings or afforested. This biotope section, which is developed in a calcareous and an acidophytic variant, represents a Red List habitat in which Sileno otitae-Festucetum brevipilae and Diantho deltoides-Armerietum elongatae interpenetrate. Accordingly, meadow saxifrage (Saxifraga granulata) and sea pink (Armeria maritima, of the leadwort family) which is typical for the coastal region of the Baltic Sea, are dominant parts of the community. The highest variety of insects in the Botanical Garden can also be encountered here.