Elodea canadensis Michx. − an alien plant species in Arkhangelsk Region, NW Russia

Lead Author Olga, Galanina
Institution Contact St. Petersburg State University, Institute of Earth Science, 199034, St. Petersburg, Russia
Co-Authors Dmitriy Philippov I.D. Papanin Institute for Biology of Inland Waters of Russian Academy of Sciences, Russia
Theme Theme 1: Vulnerability of Arctic Environments
Session Name 1.7 Invasive species in Arctic ecosystems in the changing world: Is it a real threat?
Presentation Type Poster
Abstract text The big river valleys are the natural corridors for migration of alien plant species and penetration into the northern ecosystems. The data on distribution of Elodea canadensis Michx., an invasive aquatic plant of North American origin, over the Arkhangelsk region, North-West Russia is given.
This alien plant species appeared, for the first time, in the White Sea basin about 100-110 years ago. It was recorded in the tributaries of the upper course of the Sukhona River in 1920th (Perfiljev 1934). In 1932 Elodea canadensis was collected by A.P. Shennikov in the river basin of Vajmuga (a left bank of Emtsa River). In 1940 it was already seen in the upper course of the Northern Dvina River. In mid-1960th this plant spread along the whole valley of the Northern Dvina River. Later, the floristic revisions of this species had proved its distribution over the rest of Arkhangelsk region (excluding islands) (Vekhov 1994; Schmidt 2005; Razumovskaya et al., 2012; Herbaria: LE, LECB, IBIW). It was noticed that Elodea canadensis is nearly absent in the big rivers, but it is rather abundant in the small ponds of the river valleys.
Our data show that Elodea canadensis forms the plant communities in about 60-70% of oxbow lakes in the middle courses of Northern Dvina and Pinega Rivers. This fact, probably, can be explained by the young age of oxbow lakes and ponds, peculiarities of their hydrologic and hydro chemical regimes, underlying calcareous and gypsum bedrocks.
Elodea canadensis was noticed in the slow and shallow waters of small rivers; less often it occurs in the medium-size rivers on sandy-silt grounds with a depth up to 0,6-0,8 m. It replaces the native species of aquatic macrophytes acting the most actively at the initial stages of plant successions.
This work was supported by the RFFR (grant № 13-05-00837).