Invasive alien species

Invasive alien species are species that are not originally part of a habitat and that have been introduced to a habitat by mankind either intentionally or unintentionally. We prevent the spreading of detrimental plant and animal species through different means.
The European rabbit is also known as the ‘city rabbit’. Photo: Päivi Leikas
The European rabbit is also known as the ‘city rabbit’. Photo: Päivi Leikas

How we combat invasive alien species

Our goal is to restrict the detrimental effects of invasive alien species on Helsinki nature and the well-being of city residents as well as prevent the spreading of invasive species to elsewhere in Finland. We combat invasive alien species in a systematic, persistent manner, and we have an up-to-date, geographic data based database of the species. We also aim to increase awareness regarding invasive alien species and thereby reduce the harm they cause. We take invasive alien species into account also in construction: when transporting soil, we are careful not to transport invasive species with it.

Different types of invasive alien species

The species to be prevented have been decreed in an act on invasive alien species. The most harmful invasive alien species found in Helsinki are hogweeds, the Himalayan balsam, the rugosa rose, the lupin and large knotweeds. We have combated these for several years now in valuable nature sites, in connection to maintenance work in parks and other green areas, and with volunteer activities.

The most detrimental invasive animal species are the American mink, raccoon dog, European rabbit and Spanish slug. We combat these with various methods depending on the environment and the season. We combat invasive alien species while also considering the perspective of animal welfare.


Take part in combating invasive species

It is important that residents do not help invasive alien species spread further. Please make sure that invasive alien species, such as the previously commonly grown garden plants rugosa rose, large-leaved lupine or certain hogweeds, do not grow in your yard or allotment.

The Spanish slug and European rabbit are familiar pests in many gardens. We help residents combat invasive alien species by sharing information about the topic, for example. According to the Animal Welfare Act, no unnecessary suffering can be caused to animals, and this also applies to invertebrates and animals considered pests.

The leads to external service) website is an excellent source for instructions on how to identify and combat invasive alien species.

Combatting invasive alien species with the help of volunteers

You can also take part in volunteer days combating invasive alien species or hold your own volunteer event. The City will provide you with advice and help. Volunteer events are often focused on invasive plant species, but they have also been organised to combat the Spanish slug, for example. You can find out more details on the volunteer activities website. 

Take part in volunteer work combating invasive alien species(Link leads to external service)