| Popis: |
The results of complex investigations of Typha laxmannii Lepech (Typhaceae) in Ukraine are presented. The information on the history and modern distribution of the species, its ecological and phytocoenotic peculiarities are summarized. It is a perennial herbaceous plant, alien species of Asian origin which is characterized by a progressive type of range in the country. For the first time in the flora of Ukraine T. laxmannii (under the name T. stenophylla Fisch. ex Mey.) was recorded in 1902 in the south of Ukraine (Kherson Oblast) by Paczosky. Maps of distribution of the species was prepared on the basis of Ukrainian Herbaria, literature sources and electronic databases. Distribution took place in the northern, eastern and western directions as a hydrochore and anemochore. Now the species is distributed almost throughout Ukraine, but with a majority of records in the central and western parts of Ukraine. The association Typhetum laxmannii formed by this species is common for Ukraine. Depending on the ecological and geographical conditions and floristic composition, 3 following variants in this association were identified: var. typica, var. T. latifola, and var. Schoenoplectus lacustris. Coenoses within this association are distributed almost throughout the whole territory of Ukraine, but the ecological optimum of the species coenotic area is observed in the South of the country, in the Steppe zone, on slightly saline, well-watered substrates. Based on studies conducted in Zhytomyr Oblast in 1995–2021, the expansion rate of T. laxmannii was calculated – from the South to the North – in average 16.6±1.09 km·year-1. From the sites of the primary penetration of the species into the region (Forest-Steppe zone), the expansion rate of it toward to the North was significantly lower (7.7–9.0 km·year-1) compared to that in the Forest zone – Ukrainian Polissia (23.4–31.9 km·year-1). |
