Urban ecosystems as locations of distribution of alien aquatic plants

Abstract Peculiarities of alien macrophytes invasions into aquatic ecosystems located at urban landscapes were investigated on an example of water bodies, rivers and streams located within the Kyiv City (Ukraine). There have been recognised seven species of alien aquatic macrophytes established at the territory of Kyiv City, representing 11% of the hydrophilic flora of the city. The representatives of the recent invasions Egeria densa, Elodea nuttallii and Pistia stratiotes in comparison with Elodea canadensis were characterized by a wider ecological valence concerning the contents of nitrogen compounds in water. Significant variability of morphometric parameters of coenopopulations of alien species formed in different environmental conditions was recognised. There was observed that the individuals of Pistia stratiotes from eutrophic water bodies formed significantly larger surface organs, and the individuals from meso-eutrophic reservoir had a larger number of leaves in the rosette, and more numerous and longer roots. The alien macrophytes species dwelling in the water bodies of the city were characterized by wide ecological amplitudes, high stress tolerance, high reproduction rate, high naturalization degree, allowing these species to use the resources of their new environment inaccessible for the local species and significantly affecting the ecosystem homeostasis and transformation.