EPPO Global Database

EPPO Reporting Service no. 01 - 2018 Num. article: 2018/021

Four new EPPO datasheets on EPPO A2 invasive alien plants

Four new datasheets have been published on invasive alien plants recommended for regulation as A2 pests in 2017.

Salvinia molesta (Salviniaceae)
In the EPPO region, Salvinia molesta has been found in Austria, Belgium, France (Corsica), Germany, Italy, Israel, the Netherlands and Portugal, but it is not clear if reports represent established populations. In France, the species was first found in Corsica in 2010, in a water reservoir.  S. molesta is most often found in stagnant or slow-flowing waters such as lakes, slow-flowing rivers or streams, wetlands, rice paddies, irrigation channels, ditches, ponds and canals. Dense mats of S. molesta have the potential to reduce access to the water for recreation, interfere with various engineering structures such as weirs, floodgates or locks, block drains and cause flooding, prevent livestock reaching water; prevent photosynthesis in the water below the mat, and have negative impacts on native animals and plants, and more generally significantly alter aquatic ecosystems and reduce the aesthetic appeal of water bodies.

For the full datasheet: https://gd.eppo.int/taxon/SAVMO

Pistia stratiotes (Araceae)
In the EPPO region, Pistia stratiotes was first recorded in the Netherlands in 1973 but plants did not become established. First reports from Austria and Germany were made in 1980. Repeated introductions failed to establish in Germany up until 2005, however, since 2008, an established population has been permanently present in thermal sections of the River Erft. In Italy, P. stratiotes was reported first in 1998. P. stratiotes is now considered as established in at least one location in France, in a canal along the Rhône river, where first observations dated back to 2005. P. stratiotes grows in slow moving rivers and reservoirs, irrigation channels, ponds, lakes, canals and ditches. Dense mats of P. stratiotes block sunlight, reducing primary production, decreasing water turbidity. Furthermore, the water shaded by P. stratiotes shows decreased levels of oxygen and increased levels of nitrate, ammonium and phosphorus. As a result of the altered habitat, submerged vegetation has been shown to decrease under dense mats along the river Erft in Western Germany.

For the full datasheet: https://gd.eppo.int/taxon/PIIST

Gymnocoronis spilanthoides (Asteraceae)
Gymnocoronis spilanthoides has been reported as casual in 1988 in Hungary, occurring in the thermal waters of Lake Héviz and ditches near Keszthely. Two naturalised occurrences have also been reported in North-Western Italy (Lombardia region). The population in Italy stretches along the water body for over 500 m, and occupies the whole canal width (up to 4 m wide). Within its introduced range, G. spilanthoides grows in wetlands, particularly degraded waterways forming marginal clumps on the edge of slow flowing or still water bodies and also forming dense sprawling floating mats in rivers (including tidally influenced areas) and reservoirs, irrigation channels, ponds, lakes, canals and ditches. G. spilanthoides can have negative impacts on biodiversity and causes other environmental damage. Because G. spilanthoides grows very quickly, it can rapidly cover water bodies with a floating mat, excluding other plants and the animals that rely on them. Water quality may decline if large amounts of plant die-off and rot under water.

For the full datasheet: https://gd.eppo.int/taxon/GYNSP

Cardiospermum grandiflorum (Sapindaceae)
In the EPPO region, C. grandiflorum has non-native records from France (Landes and Alpes-Maritimes departments where it is considered a casual species in the process of becoming established).  The species is also present in Italy (Liguria, in the mainland and the Catania (Canalicchio) in the island of Sicily), Malta (considered as an invasive species), Portugal (Madeira Island), and Spain (Canary Islands: Gran Canaria, Tenerife, La Gomera, La Palma). In the Alpes-Maritimes department in France, the species was first recorded in Menton in the City of Beausoleil in an urban area. C. grandiflorum prefers open habitats though it may grow well in forest edges. C. grandiflorum thrives in well-drained soil types. Research on invasive populations from Australia found soil types to vary substantially among regions of high-density populations indicating a wide edaphic tolerance by the species. In its invasive range C. grandiflorum typically forms dense draping carpets/mats, smothering large areas of underlying vegetation.

For the full datasheet: https://gd.eppo.int/taxon/CRIGR


EPPO Secretariat (EPPO Global Database: https://gd.eppo.int/)