Alien plants in Central European river ports

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.

Spatiotemporal patterns of non-native terrestrial gastropods in the contiguous United States

“…Comparable areas of human population density located away from coastal areas tend to have much lower non-native species diversity. This pattern conforms to findings that ports of entry are gateways to many introduced species, especially non-native horticultural plants (Jehlik et al 2019) and animals such as invasive insects (Langor et al 2009) and invasive terrestrial gastropods (Bergey et al 2014) that are hitchhikers on such plants.…”

The functional composition of the neophytic flora changes in response to environmental conditions along a rural-urban gradient

“…Further, the highly heterogeneous structure of urban areas offers a wider range of different habitats (Kühn et al 2004). In addition, cities represent hotspots of human mobility and transportation which are considered important factors determining the number of invasive species (von der Lippe and Kowarik 2008, Jehlík et al 2019, Seebens 2019.…”

Flora y vegetación de las dunas de la Playa Grande de Cartagena, una playa urbana en Chile central

“…Comparando la proporción de alóctonas del sitio estudiado con las de otros sitios en la misma región administrativa (Tabla 8) se observa que, por ejemplo, en las desembocaduras del río Aconcagua (Arancibia, 2006) y del estero Reñaca (San Martín et al, 2001), la proporción de especies alóctonas también es alta y alcanza a un 64 % en ambos casos. Al respecto resulta preocupante que, de acuerdo con lo reportado por Jehlík et al (2019) para los puertos fluviales europeos, la proximidad de la playa Grande de Cartagena con el puerto de San Antonio, el más importante del país (Directemar, 2020), predice un posible incremento de las especies exóticas asilvestradas. Tabla 7.…”

“…En particular, esto también se observó en las localidades ubicadas cerca de las playas y de las dunas litorales, que son ambientes susceptibles de ser invadidos por las plantas alóctonas tal como se ha descrito en México, Australia, España y Sudáfrica (Castillo & Moreno, 1996;Heyligers, 2008;Asensi et al, 2014;Cowling et al, 2019). Relacionado con ello, Jehlík et al (2019) mostraron que los recintos de los puertos fluviales de Europa central contienen una alta proporción de especies exóticas asilvestradas (41 %), cuya abundancia aumenta con la superficie del puerto, siendo éstos importantes núcleos de dispersión de especies alóctonas asilvestradas hacia el interior de los países.…”