Naturschutz-Management auf Xerothermrasenstandorten in Sachsen- Anhalt: Gefährdungsanalyse und Entwicklungsstrategien am Beispiel des Naturschutzgebietes „Lämmerberg und Vockenwinkel“

Abstract

Baier, A.; Tischew, S.: Nature Conservation Management on dry grassland sites in Sachsen-Anhalt – Investigation of threatening factors and development strategies in the nature reserve „Lämmerberg und Vockenwinkel“.- Hercynia N. F. 37 (2004) : 201 – 230.The south-exposed steep slopes of the „Süßer See“ are the main occurences of dry grassland within the „Mansfelder Hügelland“ landscape unit. The subject of this article is the nature reserve „Lämmerberg und Vockenwinkel“ and adjacent areas which are part of these steep slopes. Three transects were established in order to investigate the influence of the invasion of shrubs, of the nutrient deposition from adjacent fields, and of the increasing dominance of Arrhenatherum elatius (three important threatening factors of dry grassland) on the composition of dry grassland species and on the nutrient contents in the soil. On the former vineyard slopes in the north of the Vockenwinkel, where the soil is very shallow, the invasion of shrubs causes a reduction in the abundance of Festuco-Sedetalia species, dry grassland and ephemeral species, while Trifolio-Geranietea species and persistent Convolvulo-Agropyrion species appear more frequently. Eutrophication from adjacent fields leads to higher nutrient contents in the soil and an increasing number of ruderal plants, nitrophilous plants and weed community species. Many dry grassland species and poor soil indicator plants avoid eutrophicated areas. The increasing dominance of Arrhenatherum elatius can be observed on fine textured soils. It represses many dry xerothermic species, especially endangered species like Adonis vernalis or Muscari tenuiflorum. A development plan was worked out which integrates both species and biotope protection and the protection of successional processes. The development aims were defined according to the site conditions in order to facilitate successful and efficient management. For example, the development aim for degenerated dry grassland can be regeneration, the development of a dry Arrhenatherum elatius-meadow or the succesional invasion of shrubs – according to thickness of fine earth layer, exposure, steepness, size and importance for species protection. The management should concentrate on priority areas, and grazing must be optimized in order to check the described negative changes of xerothermic grassland.