Diagnostic species are crucial for the functioning of plant associations in inland salt marshes.

Salt marsh vegetation is considered unique and valuable and has been legally protected in Europe for years but is still declining. Its protection is related to vegetation syntaxonomical units. The characteristic combination of diagnostic species is used to create this syntaxonomical system. The aim of our novel study was to assess whether diagnostic species are sufficient for characterising vegetation functioning. Moreover, we included biochemical traits not considered to date in vegetation ecology. We hypothesised that (1) diagnostic species are crucial for the functioning of inland salt marsh vegetation and (2) their morphological and biochemical traits define the functioning of typical salt marsh associations. We chose three typical inland associations to test our hypotheses and measured the morphological and biochemical functional traits of their diagnostic plant species. Our research has shown that diagnostic species play a crucial role not only in distinguishing typical inland salt marsh associations but also in determining their functioning. Among the analysed associations, Salicornietum ramosissimae was the most adaptable to osmotic and oxidative stress under soil salinity. Triglochino maritimae-Glaucetum maritimae showed the lowest salt resistance, as indicated by the highest osmotic and oxidative stress and stress responses. Our findings may facilitate the practical application of new approaches and protection strategies for inland salt marsh habitats.

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 description of the syntaxonomical units present in temperate European inland salt marshes and identification of their main environmental 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 species 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 vegetation - 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 availability 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.

Salicornia europaea L. Functional Traits Indicate Its Optimum Growth.

Salicornia europaea L. grows in areas periodically flooded by salty or brackish water. It has potential economic value, because it can be used as food, forage, or biofuel, and has potential in pharmaceuticals and cosmetics. Increasing interest in S. europaea is due to its extreme salt tolerance and well growth in marginal saline soils. However, the variation in its functional traits in response to environmental conditions is still poorly studied. There are still questions regarding the optimal level of salinity for different traits. Therefore, we worked to address the question if S. europaea traits from different scales are controlled by salinity level. Based on performed pot experiment, we found that almost all traits are salinity dependent but affected in different ways. We demonstrated that morphological, biomass, and anatomical properties indicate optimum growth between 200 and 400 mM NaCl and growth limitations at 0, 800, and 1000 mM NaCl. Moreover, we found the most affected traits which include photosynthetic pigments and protein content, plant surface area, peroxidase activity, and anatomic traits related to cell shape. Our results significantly expanded the knowledge about S. europaea functional traits variation in response to salinity, which can be important for discovering regulating processes and for possible future agricultural applications.

Invasive Plant Species Distribution Is Structured by Soil and Habitat Type in the City Landscape.

Invasive alien species (IAS) is a global problem that largely relates to human activities and human settlements. To prevent the further spread of IAS, we first need to know their pattern of distribution, to determine which constitutes the greatest threat, and understand which habitats and migration pathways they prefer. Our research aimed to identify the main vectors and distribution pattern of IAS of plants in the city environment. We checked the relations between species distribution and such environmental factors as urban soil type and habitat type. We applied data on IAS occurrence (collected in the period 1973-2015) in 515 permanent plots with dimensions of 0.5 × 0.5 km and analyzed by direct ordination methods. In total, we recorded 66 IAS. We found a 27% variance in the IAS distribution pattern, which can be explained by statistically significant soil and habitat types. The most important for species distribution were: river and alluvial soils, forests and related rusty soils, and places of intensive human activities, including areas of urbisols and industriosols. Our results provide details that can inform local efforts for the management and control of invasive species, and they provide evidence of the different associations between natural patterns and human land use.