Fløjgaard, C., Nygaard, B., Eriksen, P.N., Mielic, C. & Ejrnæs, R. 2022. Evidensbaseret forvaltning af Kongenshus Mindeparks biodiversitet. Kortlægning, målsætninger og virkemidler. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 36 s. - Teknisk rapport nr. 228. http://dce2.au.dk/pub/TR228.pdf

Summary

Hedeselskabet contacted Aarhus University with a desire to improve the knowledge base for a more ambitious management of nature and biodiversity towards a wilder state in Kongenshus Mindepark.

The mapping of nature types shows that Kongenshus is dominated by large areas with dry heath and small areas with meadow, marsh and fen. Besides the flowering dwarf shrubs, there are generally few flowers on the heath surface, which appears monotonous and without variation in the form of bare sand and woody plants. Resen Bæk is in an unusually good condition for a Danish stream without a clear nutrient load, regulation or drainage.

National monitoring data indicate that the state of dry heaths is generally deteriorating, and analyses of monitoring data from Kongenshus Mindepark show the same picture. There is a significant negative development in the average species score, which suggests an improvement of robust species and a decline of more vulnerable species. There is a non-significant decline in the number of particularly vulnerable species (“star species”).

An inventory of species in Kongenshus in summer 2021, along with previously known data, shows that there are 35 red-listed species in Kongenshus Memorial Park, of which 15 are associated with heaths. In the surroundings of Kongenshus, there are 46 red-listed species associated with heath, which will potentially benefit from a management that promotes a greater variety of habitats. The red-listed species are typically associated with heaths, marshes, bare sand, low vegetation, flowers, dead woody plants and dung.

Based on the above, a number of objectives are recommended.

Objectives for habitats:

1. Increase the diversity of plant growth
2. Increase the area of bare sand and soil
3. Ensure the presence of dung from large herbivores throughout the year
4. Ensure a rich flower bloom and a long flowering season
5. Allow the growth of woody plants to solitary trees, shrubs and scrubs and preserve old trees.

Objectives for natural processes:

1. Restore a more natural grazing process based on perennial grazing by large, indigenous herbivores without subsidy feeding
2. Ensure the natural hydrology in the wet parts of the area
3. Promote spatial variation of disturbances
4. Increase the area and the variation in habitats that are managed in a context.

Recommendations for the choice of tools:

1. Grazing: A more natural grazing process can be approximated by practicing full-year grazing without subsidy feeding. Horses or oxen, but also European bison, wild boar, elk, red deer and fallow deer are relevant, but we do not recommend grazing by sheep and goats, as is typically practised in nature conservation today.
2. Machine peeling will immediately create bare soil/bare sand and benefit endangered species associated with this habitat. Heavy grazing animals can maintain and increase the amount of exposed substrate.
3. Fire can be a means to counteract negative effects of nitrogen deposition, but the biodiversity effects are less well known.
4. We recommend limited use of mechanical mowing/clearance, which can lead to homogenisation and that it is only applied if there is a risk that eutrophication or overgrowth threatens the biodiversity of the heath.
5. Large, cohesive nature areas with grazing, also in forest reserves, are recommended as many species are associated with transitions between light-open and woody plant-dominated areas.
6. In the southern part of the area, Resen Bæk can be protected against leaching of nutrients by purchasing and setting aside agricultural land.
7. A vision of the future could be creating an even larger and more varied, coherent nature area by establishing connections to Hald Ege, Karup Å and Dons Sande.