Studies of four invasive alien plants in Southwestern Georgia
The distribution and invasiveness of four alien plant species was studied in the Chorokhi Delta in South-West Georgia.
Ambrosia artemisiifolia (Asteraceae: EPPO List Invasive Alien Plants) is native to North America and was first recorded in Georgia in the early 1900s along the coastal areas of the Black Sea. In the Chorokhi Delta, A. artemisiifolia occurs on different soil types and is abundant along the edges of canals, in ruderal areas and edges of forests. In these areas, A. artemisiifolia inhibits the growth of native plant species.
Sicyos angulatus (Cucurbitaceae: EPPO List Invasive Alien Plants) is native to North America and was first recorded in Georgia in 2012 in agricultural habitats in the Chorokhi River Valley. In 2014, Sicyos angulatus was recorded from the Chorokhi Delta. It is widespread in moist soils along the edges of rivers, agricultural areas and semi-natural habitats. With its climbing habit, S. angulatus can smother native vegetation.
Solidago canadensis (Asteraceae: EPPO List Invasive Alien Plants) is native to North America and was first recorded in the surroundings of Ochamchire in the 1920s. The first individual specimens of S. canadensis were recorded in the Adjara region in 2011. In 2019, S. canadensis was recorded in the Chorokhi Delta and is widely distributed in South Kolkheti, occurring along roadsides, railways, in ruderal areas, along edges of canals and rivers, in abandoned construction sites, wetlands and degraded cleared forests.
Verbena brasiliensis (Verbenaceae), native to South America, was first recorded in the Black Sea area and has began to spread rapidly since the early 2000s. It grows along highways and around railway stations and the edges of rivers in low lying habitats in Western Georgia. In its native range, V. brasiliensis is an annual or short-lived perennial. In the Chorokhi Delta, it is a perennial which allows the species to dominate the habitats it invades. The species can produce up to 100 000 seeds with a high germination rate.
Sources
Mikeladze I, Manvelidze Z, Tsiskaridze D, Shainidze G (2023) Distribution and invasiveness of four non-native species of plants in ecosystems in the Chorokhi delta (SW Georgia). European Journal of Environmental Sciences 13, 80–89.