Vegetation of temperate inland salt-marshes reflects local environmental conditions

Inland salt marshes are recognized as habitats of unique and valuable vegetation at the European scale. There is still a lack of generalization regarding its vegetation syntaxonomy and environmental requirements, which is needed for its effective protection. To falsify our hypothesis about vegetation dependence on environmental requirements we aimed at descrip-tion of the syntaxonomical units present in temperate European inland salt marshes and identification of their main envi-ronmental drivers. In our work we focused on the vegetation from the northern part of temperate salt marshes to limit confusion related to the geographical ranges of species. We collected the database of 968 vegetation plots from different European countries and applied the Cocktail method to analyze the data. Based on results, expert knowledge, existing syntaxonomical classifications and information from the literature, we identified diagnostic, constant and dominant spe-cies for individual syntaxonomical units. Then, we compiled maps of the vegetation unit distribution, and identified the most important environmental factors for the analyzed vegetation using statistical and multivariate methods, including canonical variate analysis. We classified the analyzed vegetation into nine classes, including two typical for salt-marsh veg-etation - the Therosalicornietea and Festuco-Puccinellietea. Within these two classes, we distinguished two alliances and a total of five associations. The classes differ the most in terms of species preferences to salinity, soil moisture, light availabil-ity and soil nitrogen content. In addition salt marsh associations differ also by soil reaction and soil organic matter content. This provides direct implications for salt marsh sustainable management.

Automated summary

Inland salt marshes in Europe are unique and valuable habitats, but there is still a lack of understanding regarding their vegetation classification and environmental requirements. In order to investigate the relationship between vegetation and environmental factors, researchers collected a database of vegetation plots from various European countries and analyzed the data using statistical and multivariate methods. They identified nine classes of vegetation, including two typical salt-marsh vegetation classes, and found significant differences in species preferences and environmental factors among these classes. This information has direct implications for the sustainable management of salt marshes.