New record of Ludwigia peploides subsp. montevidensis in Greece
According to Zotos et al. (2006), Ludwigia peploides (Onagraceae - EPPO List of Invasive Alien Plants) has been reported in Southern Turkey in 1998, and Ludwigia peploides subsp. montevidensis has been recorded in 2001 in 3 localities of the Lake Lysimachia, in the Western chain of the Greek wetlands, covering in total 0.7 ha. The Lake Lysimachia has a rich biodiversity and has been proposed to be part of Natura 2000 in Greece. At the time of the publication, L. peploides was recorded in 3 sites, and the total number of plants in these 3 sites was estimated as 10 000 individuals.
In 2 locations where this species is recorded, the invaded sites are seasonally flooded for 6 to 8 months in winter, and are subject to intensive human activities in summer, with the cultivation of tobacco and maize. In the third locality, flooding lasts all year long, and the banks of the channel are moderately inclined and link Lake Lysimachia to Lake Trichonida.
From phytosociological relevés performed on the invaded sites, it appears that L. peploides subsp. montevidensis develops in 2 types of vegetation community with the following soil characteristics:
- in Phragmites australis (Poaceae) communities, L. peploides subsp. montevidensis grows on loamy-sandy soils with an average moisture of 30.8%, average organic matter of 5.7%, and average pH of 7.5.
- in Paspalum paspalodes (Poaceae) communities, it grows on loamy sandy soils with an average moisture of 17.6%, average organic matter of 7.8%, and average pH of 7.4.
The pathway of introduction of L. pelploides in Lake Lysimachia remains unknown, but it may have been introduced by birds, as the lake is a station for migratory birds. The spread and behaviour of the species will be followed, in order to provide evidence on the dynamism and aggressive expansion of this species.
Zotos A, Sarika M, Lucas E, Dimopoulos P (2006) Ludwigia peploides subsp. montevidensis, a new alien taxon for the flora of Greece and the Balkans. Journal of Biological Research 5, 71-78.