Main Article Content
Springs are unique but understudied habitats. Diatom communities have received some attention but have remained largely unknown in the south-western Alps. We therefore studied the springs of the south-western extreme of the Alpine mountain range. We analysed epilithic and epiphytic assemblages in 48 springs of different ecomorphological types, located on contrasting lithological substrata (carbonate/siliceous). Moreover, phytosociological relevés were carried out for carbonate springs. The diatom flora consisted of 223 taxa. Most (198) of the taxa were included in the Red List, and 12.5% belonged to threatened categories. Characteristic spring taxa (crenophiles) were present. The ecological preferences of crenophilous diatom species described in the eastern Alps were confirmed. Diatom species characteristic of the lake-littoral zone were found in pool springs. We observed no significant differences in species richness and diversity between epilithic and epiphytic assemblages, but some species showed a preference for bryophytes, and five occurred in the epibryon only. As regards moisture conditions, 15% of the taxa occurred on wet or temporarily dry sites, and 4% lived mostly outside water bodies. The main environmental factors influencing diatom assemblages were pH, conductivity, altitude, and shading. The carbonate-substratum crenic vegetation was composed of a mixture of vascular plants and bryophytes, which find their ecological optimum in springs. Bryophyte cover was dominant, with the most abundant taxa belonging to the genus Palustriella. The vegetation corresponded to the Cratoneuretum commutati association.
Acta Botanica Croatica is an Open Access journal with minimal restrictions regarding content reuse. Immediately after publishing, all content becomes freely available to anyone for unlimited use and distribution, under the sole condition that the author(s) and the original source are properly attributed according to the Creative Commons Attribution 4.0 International License (CC BY 4.0).
CC BY 4.0 represents the highest level of Open Access, which maximizes dissemination of scholarly work and protects the rights of its authors. In Acta Botanica Croatica, authors hold the copyright of their work and retain unrestricted publishing rights.
By approving final Proof the authors grant to the publisher exclusive license to publish their article in print and on-line, in accordance with the Creative Commons Attribution (CC-BY-4.0) license.