Suspected invasive plants are alien species that spread so strongly and quickly that they can supplant native species and cause damage. The indicator incorporates the plants listed in the Watch List of invasive alien species in Switzerland because they have the potential to cause damage (for example in the area of health and economic activity). Their spread must be monitored and if necessary halted. These species are already causing damage in neighbouring countries.

There were 21 alien species susceptioble of causing damage in Switzerland in 2008. This fact should be seen as negative - there is no limit value, however the number of invasive plant species should be kept as low as possible.

Information in accordance with the CPS-SKEW Watch List. http://www.cps-skew.ch/english/black_list.htm