Successful Conservation Of Species-Rich Grasslands In Central And South-West Luxembourg - First Results

Species-rich grasslands, most often the result of traditional agricultural practices, are important habitats within the cultural landscapes of central and western Europe. Despite conservation efforts at a national and international scale, many types of these grasslands are severely threatened of disappearing. Contractual nature conservation schemes with financial rewards for low-intensity management are deemed an important instrument for maintaining characteristic plant communities. However, long-term data sets that examine the efficiency of these schemes are rare. The present study compares plant species abundance lists gathered in various surveys undertaken in low-intensity grasslands in central and southwestern Luxembourg over the course of several decades. These vegetation lists, of which one pair is available for every site included in the analysis, and which have been recorded in intervals of up to 16 years, should provide an indication as to the effects of extensive management on vegetation composition. All available data was quality assessed and standardized before the analysis. The resulting dataset with 180 species lists from 90 survey sites was analysed by NMS-ordination, RDA-analysis and ANOVA in order to evaluate potential differences in vegetation composition over time and in relation to various variables. The high initial ecological quality of the grassland communities was conserved at 75% of the surveyed sites and at some sites it had even increased over time. Plant species diversity was lowest at sites with high Ellenberg-nutrient values, underlining the importance of zero fertilization for the conservation of species-rich grasslands. A slight increase in species diversity was found at more than half of the sites. However, this increase did not include any red list species. We therefore highlight the necessity for targeted restoration measures, including the reintroduction of threatened plant species, as extensification measures alone are insufficient for the restoration of typical plant communities. Some species favored by high soil nutrient levels decreased in abundance between the two survey dates, while other species showed a significant increase. The limitations of the present study, due notably to the collation of data from different sources and gathered by different surveyors, are discussed. Nevertheless, our results show that low-intensity grassland management within the framework of contractual nature conservation initiatives can preserve threatened grassland plant communities. The continuation as well as the optimisation of existing schemes, also through the increase in subsidies, accompanied by regular monitoring, are therefore an absolute necessity, even more so regarding the ongoing decline of low-nutrient meadows.