Alien plants in Central European river ports

Vladimír Jehlík,Jiří Dostálek,Tomáš Frantík

doi:10.3897/neobiota.45.33866

Abstract

River ports represent a special type of urbanized area. They are considered to be an important driver of biological invasion and biotic homogenization on a global scale, but it remains unclear how and to what degree they serve as a pool of alien species. Data for 54 river ports (16 German, 20 Czech, 7 Hungarian, 3 Slovak, and 8 Austrian ports) on two important Central European waterways (the Elbe-Vltava and Danube waterways) were collected over 40 years. In total, 1056 plant species were found. Of these, 433 were alien, representing 41% of the total number of species found in all the studied Elbe, Vltava, and Danube ports. During comparison of floristic data from literary sources significant differences in the percentage of alien species in ports (50%) and cities (38%) were found. The number of alien species was closely related to port size, but the proportion of alien species expressed as a percentage of the total number of species did not depend significantly on port area. The proportion of alien species in both studied waterways decreased with distance from the sea and was highest in the Hungarian ports and lowest in the Czech Republic, Austria and Bavaria. Lower levels of shipping towards inland regions due to decreased river flow are likely the reason for this trend. The dissimilarity in the species composition of alien and native flora between individual river ports increased with increasing inter-port distance. Neophytes presented a stronger distance decay pattern than did either native species or archaeophytes of the Danube inland ports, potentially due to the different cargoes of individual ports, which may affect the introduction of different neophytes from different geographic areas. The results show that river ports in Central Europe should be regarded as a type of industrial area and deserve full attention with regard to the distribution and spread of alien plants.

Highlights

Many studies have demonstrated that cities are hotspots of alien plants (e.g. Pyšek1998; Sukopp 2002; Wittig 2002; Clemants and Moore 2003; Zerbe et al 2004; Ricotta et al 2009; Zhao et al 2010; Lososová et al 2012; Aronson et al 2014)
40-year study of flora and vegetation in 54 river ports of Central Europe (Jehlík 2013), this paper presents detailed information on alien plants that occur in this specific type of industrialized area
The results of this study demonstrate that river ports contain high proportions of alien plant species

Summary

Introduction

Many studies have demonstrated that cities are hotspots of alien plants (e.g. Pyšek1998; Sukopp 2002; Wittig 2002; Clemants and Moore 2003; Zerbe et al 2004; Ricotta et al 2009; Zhao et al 2010; Lososová et al 2012; Aronson et al 2014). Traffic junctions and transshipment points of goods have had an important role, as they represent the sources of occurrence and spread of invasive plants (Jehlík and Hejný 1974; Forcella and Harvey 1988; Kornaś 1990; Jehlík et al 1998; Song and Prots 1998). For this reason, urban-industrial areas are regarded as the main drivers of biological invasions (Wittig 2010)

Methods

Results

Conclusion