Zielkonflikte zwischen Biodiversitätsschutz und Prozeßschutz bei der Regeneration des ehemaligen Küsten- und Wiesenvogelschutzgebietes „Priwall“ bei Travemünde

The present work deals with the planning of the sustainable regeneration of a former coastal bird sanctuary, the peninsula "Priwall" in the mouth of the river Trave into the Bay of Lübeck, the most southwestern fjord of the Baltic Sea. First of all, the ecological causes for the decline of breeding colonies and resting populations of ground-dwelling wading birds and waterbirds had to be identified, also under special consideration of their historical development. The subsequent assessment of the regenerative capacity of the ecofactors in unfavorable condition enabled the formulation of the goals for regeneration and a derived action plan as part of a coordinated guiding vision development. In Chapter 1, the characteristic breeding and resting bird inventory of the Priwall is elaborated as that of a grazing bird monotony typical of the Baltic Sea coast. This chapter also describes the special ecological function of the breeding colony of the lapwing (Vanellus vanellus) on the Priwall as an ecological protective screen for the population of a species- and individual-rich grazing bird monocoenosis. Chapter 3 therefore deals in particular with the ecological requirements of the breeding colony of the lapwing on Priwall. In this context, own investigations on the Priwall, as well as in the comparison areas Meggerkoog (district Schleswig-Flensburg, Eider-Treene-Sorge lowlands) and Wallnau (island Fehmarn, district Ostholstein) for the first time draw special attention to the relationship between the height of the forest edge adjacent to the grassland of the "Priwallwiese" serving as breeding habitat and the distribution of lapwing clutches. The significant correlation found indicates a saturation function for the conditions on the Priwall meadow with a limiting angle of 11° horizon height with regard to suitability as a nest site. In chapter 4, a comprehensive description and evaluation of the biological diversity on the area of the present nature reserve "Südlicher Priwall" is given. In this context, all available biologicalecological data, especially since the beginning of the 20th century, are considered. Chapter 5 finally works out the demonstrably considerable factors of the degeneration and thus also of the regeneration of the bird sanctuary typical for the Baltic Sea coast on the Priwall from the bases given in the previous chapters, evaluates the regeneration ability qualitatively and quantitatively and formulates thereupon comprehensive and with regard to the actual situation of the nature reserve "Südlicher Priwall" weighed target conceptions for its regeneration. With reference to the correlation between forest edge height and border distance of the lapwing nests derived in chapter 3, the increase of the grassland share in dead former forest areas and the withdrawal of the tall hybrid poplars at the edge of the Great Meadow are considered as essential measures. The recognized "limit angle" here allows a quantitative limitation of this measure to the necessary minimum. In addition to the maintenance (or expansion) of grazing, further measures regarding the raising of the water level as well as the protection of predators are developed and presented.