Tropical Invaders Egeria densa Planch., Pistia stratiotes L., and Eichhornia crassipes (Mart.) Solms in Aquatic Ecosystems of Kyiv

Results of the study of the southern tropical macrophytes (Egeria densa, Pistia stratiotes, and Eichhornia crassipes) occurring in water bodies of Kyiv under conditions of temperate continental climate are given in the paper. Different ways of the invasion of these alien species and their ecology were investigated: the history of their appearance in water bodies of Ukraine, the peculiarities of phytocenotic structure of their communities, production and morphometric parameters in local populations, and invasive behavior. It has been found that the studied species are capable of producing significant phytomass: Egeria densa -to 0.5 kg/m2, Pistia stratiotes - to 6 kg/m2, whereas Eichhornia crassipes - to 13 kg/m2 of net phytomass. The severity of production parameter variations within local populations is indicative of plasticity under conditions of the region of investigations, and also of the capability of the studied plants to adapt to the conditions of the secondary area of distribution.