Prvi nalaz vodenog oraška (Trapa natans L., Trapaceae, Myrtales) u Centralnoj Srbiji

Water chestnut (Trapa natans L.) is a floating macrophyte that generates differing views on its role and importance in aquatic ecosystems. It is protected as a rare species in a number of European countries and is an invasive species in some regions of the world. T. natans inhabits stagnant and slow flowing waters that exhibit large fluctuations in water level. Occurrence records are frequently reported from the north of the Republic of Serbia (Vojvodina Province), while there are no relevant data about its habitats in southern parts of the country. The first record of T. natans in Central Serbia was from the Međuvršje Reservoir on the Zapadna Morava River (the Danube River Basin) in 2011. A marked increase in species abundance in certain sections of the reservoir was observed in 2012. High water temperatures and continuous inflow of nutrients reported in recent years will most likely induce further propagation of this species, potentially leading to further eutrophication of the system and upsetting the ecological balance of the new habitat.Vodeni orašak (Trapa natans L.) predstavlja flotantnu makrofitu koju karakteriše različita procena uloge i značaja u akvatičnim ekosistemima. Zaštićena kao prirodna retkost u većem broju evropskih zemalja, ima status invazivne vrste u pojedinim regionima sveta. T. natans je vrsta kojoj pogoduju stajaće i sporotekuće vode sa velikim variranjima vodostaja. Česti su nalazi u severnom delu Republike Srbije (Vojvodina), dok nema relevantnih podataka o staništima u južnijim delovima. Tokom 2011. godine registrovan je prvi nalaz T. natans na području Centralne Srbije u akumulaciji Međuvršje na reci Zapadnoj Moravi (Dunavski sliv). Izrazito omasovljenje vrste u pojedinim sektorima akumulacije je evidentirano u 2012. godini. Visoke temperature vode i stalan dotok nutrijenta koje se registruju zadnjih godina verovatno će usloviti dalju propagaciju vrste. To može doprineti daljoj eutrofikaciji ekosistema i narušiti postojeće ekološke ravnoteže u novom staništu