Raphael Schallegger (Paris Lodron Universität Salzburg)
Raphael Schallegger's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Salzburg University in the year 2025 with the title:
Common Life on the Brink – A comparative analysis of animal and plant diversity on old stone walls in the city of Salzburg, Austria
The work shows how effects of wall characteristics on species number and species composition differ depending on the regarded organism group (bryophytes, tracheophytes, invertebrate animals) and compares in this context walls surrounded by “dry land” to walls built next to a water body.
Especially in cities, old stone walls represent habitats for various animal and plant species. However, owing to different characteristics (e.g. their vertical nature), they are also considered as extreme environments showing hardly uniform colonisation. During summer in 2022, plant and animal species of 79 wall faces in the city of Salzburg were recorded and morphologically identified. Besides the compilation of an inventory, effects of wall parameters (e.g. orientation, roughness, inclination) on the diversity of these organism groups were analysed.
In total, 137 tracheophyte, 37 bryophyte, and 257 invertebrate animal species were detected. All three groups had in common that only a few of their species were found on more than one wall. Instead, mostly a mixture of single individuals of many different species were recorded. Inclination and surface roughness had a significant effect only on tracheophytes and animals (and not on bryophytes), whereas wall orientation affected both plant groups, but not the animals. For all three organism groups, species composition differed between wall faces directly above a water body and wall faces above dry land. In addition, more bryophyte and less animal species were found on such “water walls” compared to “land walls”, while for tracheophytes the difference in the pure number of species was not significant. The work also emphasises the importance of old stone walls as habitats in cities regarding preservation. Moreover, it serves as a reference, based on which results and applied methods more extensive and targeted investigations of such habitats can be carried out.
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Raphael Schallegger conducted this work at the Department of Environment and Biodiversity of the University of Salzburg in the working group of Andreas Tribsch.
