New weeds in wet meadows: terrestrial forms of invasive Water Primroses (Ludwigia spp.) on meadows

Abstract

Water Primroses (Ludwigia spp.) are well-known invasive species, because they cause many problems in hydrosystems. However, they are still surprising plants both for managers and scientists regarding their ability to colonize new habitats. For some years now they have been expanding on wet meadows in protected areas. First, the two amphibious species are presented. Then the process of their colonization on meadows and an estimation of the colonized areas are detailed, morphological adaptations of terrestrial forms are analyzed. In the last part, management and mitigation experiences in different contexts underline the difficulty of a corrective management and impose preventive management as much as possible.