ESTABLISHMENT SUCCESS OF PLANT IMMIGRANTS IN A NEW WATER RESERVOIR

The set of 25 aquatic and shoreline species which immigrated to the ne w reservoir Rozkos during the 21 years after its creation were analyze d with respect to their time of immigration, distance of nearest sourc e localities, life form, seed size, and reproductive system. The reser voir consists of two parts, one with fluctuating and the other with st abilized water level. The immigrating species originated from various distances, from nearby to more than 100 km away. A distance of tens of kilometers can be overcome by many shoreline species, provided that s uitable (low competition) habitats are available. The survival time wa s correlated with the reproductive system: species with autogamic or v egetative reproduction survived longer. Establishment was more success ful under a fluctuating water level, which decreased the competitive e xclusion of immigrated species by helophytes.