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Succession and management of calcareous dry grasslands in the Northern Franconian Jura, Germany
(2009)
The massive decline of calcareous grasslands in the Franconian Jura is caused mainly by land use abandonment and afforestation. In the district Lichtenfels, the northernmost part of the Franconian Alb, management measures were put in action since the middle of the 1980s to conserve or restore those threatened ecosystems. Important actions were removal of trees (mainly Pinus sylvestris) and shrubs as well as reintroduction of sheep grazing. This study analyses the success of restoration measures taken at two Natura 2000 sites. Based on vegetation relevés from 70 sites with different land use histories, we investigate the influence of the successional status of the woodlands prior to clear-cutting and the time period of subsequent grazing on the actual vegetation. The results suggest that both factors influence species composition. On formerly dense pine woodland sites, it takes at least five years of grazing until the number of target species increases. On formerly more sparsely wooded sites, target species establish faster after reintroduction of grazing. Our results show that keeping sites open by tree and shrub removal followed by seasonal grazing are important measures to maintain and restore plant communities of calcareous grasslands in the Franconian Jura.
In this paper we aim to present data on current state of steppe-like grasslands dominated by feather grasses (Stipa spp.) in the Transylvanian Lowland (Romania), and to investigate whether management type affects species composition, biodiversity, or the occurrence of rare and endangered vascular plant species in these grasslands. Twelve grassland stands, originating from nine areas and belonging to two associations, Stipetum lessingianae and Stipetum pulcherrimae from the alliance Stipion lessingianae (Festucetalia valesiacae, Festuco-Brometea), were investigated by phytosociological sampling. Our data set contains 60 relevés originating from differently managed grasslands: grazed and abandoned stands as well as former grasslands afforested with Pinus nigra. Transylvanian stands of the Stipion lessingianae occur on steep, south-facing slopes. The species composition has an accentuated sub-continental character, including several steppe elements of Siberian and Pontic origin, many of them reaching the western edge of their distribution in this region. By comparing the species composition of the two associations, we identified 12 differential species for the Stipetum lessingianae and 19 for the Stipetum pulcherrimae, but these associations also contained many species in common, which underlines their close syntaxonomic relatedness. Grazing vs. abandonment had only a slight influence on species composition and vegetation structure, while afforestation with pines resulted in strong transformations: decreased cover of the herb layer, increased cover of litter, decreased representation of diagnostic (i.e. typical) species of the two associations but increased frequency of woody, ruderal, and mesophytic grassland species. As the Stipion lessingianae belongs to the priority habitats of the Habitats Directive, these alterations call for grassland restoration measures. Our study revealed a lack of high-quality data on the vegetation of steppe-like dry grasslands in southeast Europe, where they have their largest and best-developed stands on the continent. Thus, we emphasize the need for compiling such data and for developing a consistent supranational vegetation classification of Festucetalia valesiacae communities in this region.