The 29-hectare Mätäoja Nature Reserve and its adjacent Key Biodiversity Areas host protected habitats and endangered species, including the red-listed white adder’s-mouth orchid (Malaxis monophyllos) and the Hylochares cruentatus beetle. Himalayan balsam spreads efficiently along waterways, competes with native vegetation and poses a significant threat to the sensitive nature areas. Early and targeted removal is crucial to protect biodiversity and prevent further spread toward Helsinki.

The project will be implemented through five key activities: project coordination and planning, summer employees, volunteer-based removal events, stream warden support and field operations, and “solo volunteer events” enabled by the award-winning Finnish Crowdsorsa mobile application. All removals will be carried out using manual methods during the optimal growing season. Citizen engagement is central to the project. Residents, schools and other community groups will participate in organized volunteer events, while the Crowdsorsa app enables independent participation and rewards verified removal efforts. The City of Vantaa’s stream wardens will support field operations and logistics in collaboration with other municipal departments.

Project success will be measured through pre- and post-removal inventories, assessing reductions in Himalayan balsam coverage. The project supports Vantaa’s environmental program by increasing public awareness and involvement in invasive species management and is designed to continue beyond 2026 to ensure long-term effectiveness.

Project objectives

• The early-stage invasion of Himalayan balsam is removed entirely from the Key Biodiversity Areas (2,3 ha) and reduced to the maximum feasible extent across the protected area (29 hectares).
• Public awareness and stakeholder engagement in invasive alien species management are increased.