Invasive Himalayan balsam overruns Iidesjärvi’s southern shore, worrying birdwatchers

Three-metre-tall pink spikes of Himalayan balsam have sprung up along the slopes of a former landfill on Iidesjärvi’s southern shore, their sweet scent filling the air, Aamulehti reports. The invasive plant has spread across a wide area south of Iidesjärvi near Nekalantie. Birdwatchers and residents who use the popular walking routes are worried.

Teija Ahonen, the city’s environmental planner for invasive species, said the occurrence is known and that control work has taken place on the lake’s north and east sides. Resources are limited, so crews must prioritise sites. Tampere’s Oskari database lists more than a thousand plants at the landfill site. Records show removal efforts or other control measures there in 2018, 2020 and 2022.

Officials left the southern landfill out of this summer’s volunteer removal campaign because the area is included in the Nekalanranta general plan. The plan, approved in June, calls for replacing soil, removing invasive species, isolating the old waste fill and converting the site to a meadow with flowering shrubs and trees along the paths. The development follows the partial zoning plan for Iidesjärvi’s south shore approved in June and comes amid local debate over park plans for the shoreline that would create recreational areas while raising wildlife concerns. Local groups have been offered guidance on dealing with invasive plants, including a free May lecture on practical control measures.

Iidesjärvi is a nationally recognised bird lake. A 2018 survey recorded 42 species and an estimated 250–300 breeding pairs, and locals warn action is needed soon to prevent the balsam from spreading along the shores and into nesting habitat.