Floristic analysis of a high-speed railway embankment in a Mediterranean landscape

Abstract

-We analyzed the floristic composition of a 4.5 km-long segment of a high--speed railway in Lazio, central Italy, which travels on an artificial embankment through an intensively-farmed landscape. In total, 287 vascular plant species were recorded. The life-form distribution was found to be similar to that of the regional species pool, with high percentages of therophytes (38%) and phanerophytes (13%). In the chorological spectrum the Mediterranean floristic element prevailed (44%), while alien species were 8% of the flora. The phytosociological spectrum showed a high diversity of characteristic species from the class Stellarietea mediae or its subordinate syntaxa (26%), and in particular from the order Thero-Brometalia (Mediterranean, sub-nitrophilous annual communities). Species from forest syntaxa had a relatively high diversity (9%). These results suggest that the ecological filtering provided by the Mediterranean regional climate controlled species assemblage even in a completely artificial habitat, preventing floristic homogenization: the flora of the studied railway section is only partially »ruderalized«, while it keeps strong links with the regional (semi-) natural plant communities. However, in contrast to what is observed in central and north Europe, the railway sides studied in the present paper do not seem to represent a refugial habitat for rare species from grassland communities, mainly because in Italy semi-natural dry grasslands are still widely represented.

Analyses of the flora of railway stations in the Mediterranean and sub-Mediterranean areas of Croatia and Bosnia and Herzegovina.

“…This is consistent with the findings of Filibeck et al (2012) and Altay et al (2015) for Mediterranean railway areas, and only partly with those in central Europe (e.g., Czarna, 2005). Additionally, our finding closely agrees with the proportion of neophytes in urban flora of the main Croatian coastal cities and the city of Mostar in Bosnia and Herzegovina, and in railway stations of inland Croatia (Marković, 1977;Milović & Mitić, 2012;Maslo, 2014).…”

“…In this case, in contrast to the findings of Filibeck et al (2012) in the Mediterranean region of the Italian Peninsula, the high percentage contribution of Mediterranean taxa with co-domination of Cosmopolitans suggests that the Mediterranean climate does not act more than partly as a strong ecological filter, while the presence of cosmopolitans suggests a high degree of human impact (e.g., Dunnett & Hitchmough, 2004). Generally these taxa had a significant influence on the physiognomy of this type of man-made habitat in the area , and references therein).…”

“…In this case, the number of taxa is high when compared to the floristic richness found on railways in the Mediterranean area of Italy (Cornelini & Petrella, 1994;Filibeck et al, 2012), or some north European sites (Lejmbach et al, 1975;Warcholińska, 2008). Other authors have given quite different results for railway areas in a broad sense and over a wide geographic area (e.g., Messenger, 1968;Altay et al, 2015;Májeková & Limánek, 2016;Jehlík et al, 2017).…”

“…Some authors have analyzed the groups of plants that occur most frequently in railway areas (e.g., Brandes, 1983), while others have demonstrated the importance of elements of railway infrastructure for the expansion of these species (e.g., Rutkovska et al, 2013). In general, due to the decrease in grain and livestock rail transportation in the last few decades, railways nowadays have less rich alien flora than was observed in the first half of the 20 th century (Filibeck et al, 2012, and references therein).…”

“…Railways and railway verges have been the subject of botanical studies for more than 150 years (Filibeck et al, 2012, and references therein). In fact, there have been many different approaches to research on species occurring in railway areas.…”