Effects of grazing versus mowing on the vegetation of wet grasslands in the northern Pre‐Alps, Switzerland

Abstract

AbstractQuestionWet grasslands are among the most threatened habitats in Central Europe and are subject to loss of their unique species assemblages. Grazing and mowing are important conservation management tools for such semi‐natural habitats. The aim of this study was to investigate and compare the influence of grazing and mowing on the diversity and species composition of wet grassland vegetation.LocationMontane wet grasslands in the Gantrisch Nature Park, Switzerland.MethodsWe sampled 18 pairs of vegetation plots along land‐use borders between grazing and mowing (fence‐line contrasts), distributed over six fens, mostly belonging to the phytosociological alliance Calthion palustris. We tested for differences in structural parameters, biodiversity indices, mean ecological indicator values and the frequency of individual species. In addition, a detrended correspondence analysis was carried out.ResultsManagement type had no influence on species richness, Shannon index or Shannon evenness. Maximum microrelief, vegetation height, mean nutrient indicator value and mean competitive strategy were significantly higher with grazing, whereas the mean aeration indicator value and the mean ruderal strategy were significantly higher with mowing. Cirsium oleraceum, Filipendula ulmaria, Geum rivale and Juncus effusus, species of nutrient‐rich wet meadows, were more frequent under grazing, whereas mowing favoured grassland species with wide ecological amplitude, such as Plantago lanceolata and Trifolium pratense.ConclusionsAt the plot scale, vascular plant diversity did not differ between these management regimes. Thus, from the conservation point of view, in the study region, there is no clear preference for either management type, and both should be eligible for subsidies. At the landscape scale, it is beneficial to have both management types present to ensure high gamma‐diversity, as they favour different species.