Invasion pathways along the rivers in Serbia: The eastern corridor of Reynoutria spp.

Abstract

Increasing levels of invasion worldwide have been the source of concern for scientists, due to significant costs and efforts required for managing them. The knowledge of invasion pathways, both those of initial introduction and subsequent spread, is of key importance, since further increase in the number of pathways and vectors of invasion is predicted for the 21st century. At regional scales habitat type has proven to be a reliable predictor of the level of invasion, as certain habitat types (i.e. frequently disturbed, under strong anthropogenic influence) is characterized by high invasion levels. Riparian habitats, as hotspots of alien species diversity and primary sources of their spread, represent some of the most important invasion corridors, where water acts as an effective dispersal mechanism. Some invasive plant species, like Reynoutria spp. show a strong tendency to invade riparian habitats. Preliminary findings of field surveys aimed to assess the level of riparian invasion by Reynoutria spp. in Serbia suggest that some river basins are significantly affected by the presence of these invasive species. Bearing in mind the principal means of their propagation, further spread of Reynoutria spp. along the rivers in Serbia is to be expected over the following years.

Stepen invazija koji je u porastu širom sveta zabrinjava naučnike, zbog značajnih troškova i napora koji su neophodni u njihovom kontrolisanju. Poznavanje puteva invazije, kako početnog unosa tako i naknadnog širenja vrsta, od ključnog je značaja, jer je u 21. veku prognoziran dalji porast broja puteva i vektora invazije. Na regionalnom nivou tip staništa se pokazao kao pouzdani pokazatelj nivoa invazije, jer određene tipove staništa (često remećena, pod snažnim antropogenim uticajem) karakteriše visok nivo invazije. Riparijalna staništa, kao centri diverziteta alohtonih vrsta i primarni izvor njihovog širenja, predstavljaju neke od najznačajnijih koridora invazije, u kojima voda deluje kao uspešan mehanizam disperzije. Neke invazivne vrste biljaka, poput Reynoutria spp. pokazuju snažnu tendenciju ka invaziji riparijalnih staništa. Preliminarni rezultati terenskih istraživanja koji su za cilj imali procenu nivoa invazije riparijalnih staništa vrstama roda Reynoutria u Srbiji ukazuju na to da su slivovi nekih reka pod značajnim uticajem prisustva ovih invazivnih vrsta. Imajući u vidu osnovni vid njihove propagacije, dalje širenje Reynoutria spp. duž reka u Srbiji može se očekivati tokom narednih godina.