We have added a categroy to our field protocols. When we are surveying the 112 wetlands (batymetry, dragonflies, invertebrates etc) we now also check for selected invasive species. We have selected ca 10 species that are easily recognized and invasive, in order to get data on the occurrence of invasive species in constrcted wetlands in the agricultural landscape. It was not planned in the proposal, but our field surveys give us a good opertunity to get useful data on a large set of constructed wetlands as a side-effect. The species we check for are e.g. Nuttalls Pondweed + Canadian pondweed (Elodea canadensis + C. nutallii), Signal crayfish (Pacifastacus leniusculus), Red water lily (Nymphae alba, var. rocea) , Grass karp (Ctenopharyngodon idella), Yellow scunk cabbage (Lysichiton americanus), Himalyan balsam (Impatiens glandulifera), Japanese knotweed (Reynoutria japonica/Fallopia japonica), Giant hogweed (Heracleum mantegazzianum). The photo show signal crayfish in the wetland D31.

Canadian pondweed (Elodea canadensis) and Signal crayfish (Pacifastacus leniusculus) in the wetland D31