Monitoring of Trapa natans (Trapaceae) Populations During Reintroduction into Saratov Oblast

The possibility of introducing the species Trapa natans L. into Saratov oblast has been studied. Donor material from the lower Volga (Astrakhan oblast), the Middle Don (Volgograd oblast) and the Khopyor middle reaches (Voronezh oblast) water bodies is used. The fruits are sown within the boundaries of Saratov oblast in 77 places in the floodplains of the Khopyor, Medveditsa, Tereshka, and Volga rivers. For morphometric analysis, 16 morphometric parameters are measured in 30 rosettes from each population. The ordination of the points was performed using the PCA. The Medveditsa and Tereshka rivers turned out to be unsuitable for reintroduced populations. The reintroduction of T. natans to the floodplain of the river was successful. The reintroduction of the species into the Khopyor and Volga rivers was carried out using donor material from the floodplains of the Don River (Volgograd oblast) and the Khopyor River (Voronezh oblast). The material from Astrakhan oblast, on the contrary, is unacceptable as donor material for reintroduction into Saratov oblast. According to morphological features, natural populations from Voronezh oblast are more variable than populations from Astrakhan oblast. The population from Astrakhan oblast is characterized by larger rosettes and leaves than populations from Voronezh oblast. In the reintroduction populations created in the floodplain of the Khopyor River within Saratov oblast, the leaf and rosette parameters are higher and the fruit productivity is lower than in the donor populations from Voronezh oblast. At the same time, in the reintroduction populations of first vegetation year, compared with the donor populations, a range narrowing of morphological and productive variability of individuals is observed.