Ecological and coenotic characteristic of Cyclachaena xanthiifolia (Nutt.) Fresen. in the flora of Ukraine

Abstract

The flora of Ukraine includes Cyclachaena xanthiifolia adventitious species, which is dangerous for humans and animals. It got out of human control and spread widely throughout the whole territory, but its environmental features have not been studied enough. We found that Cyclachaena xanthiifolia is the eurytopic species in Ukraine, that is, it has wide ecological amplitude. It grows well and develops in wide weather and climatic divides: from semi-ombrophytic climate (1000 mm, Pre-Carpathian, Transcarpathia) to arid one (less than 350 mm, Prysyvashshia) in terms of climate humidity; from hemioceanic climate (Western Ukraine and the Black Sea coast) to subcontinental one (Dry-steppe and South-steppe zones) in terms of climate continentality. Its habitats are confined to flat, lowered, but well-drained and low areas. We did not find it at the altitudes of more than 500 m. This is heliophyte, a short-day plant. According to temperature requirements, it occupies an intermediate position between submesothermal and macrothermal plants that grow well when the amount of heat in April-October is from 1780 to 2620 kcal/cm2 and the sum of effective temperatures is from 2850 to 3750ºC. When it comes to demand on soil moisture, it is predominantly mesophytic plant; with regard to soil solution reaction, it is neutrophilic or subacidophilic plant; with respect to soil fertility, it is eutrophic humifilous eunitrophilic plant on ruderal habitats, and oligotrophic agumyl or sub-agumyl heminitrophilic plant on technogenic ones. The highest frequency of occurrence, abundance and the best morphological plants’ parameters were found on black earth, chestnut, and meadow soils, and the worst plants’ parameters were found on sod-podzol, brown forest, sand, saline and bog soils. In relation to landscapes cultivation, this plant is euhemerobe or polyhemerobe. It grows in the Ambrosio artemisiifolia-Chenopodietum albi, Ambrosio artemisiifolia-Cirsietum setosi, Amaranto retroflexi-Setarietum glaucae, Amaranthetum blitoidi-Echinochloetum grusgalli, Poligono-Chenopodietea communities and others in segetal biotopes. It grows in the Ivaetum xanthiifoliae, Atriplicetum tataricae, Chenopodietum glauco-rubri, Chenopodio-Аtriplicetum hastatae, Ambrosio artemisiifoliae-Xanthietum strumariae communities and others in ruderal biotopes.