Fingrid has previously erected artificial trees for flying squirrels to jump from, allowing them to glide through transmission line rights-of-way, even if there are several parallel transmission lines.
“In the future, we will establish green corridors for flying squirrels to pass through. These strips of forest will be about 50 metres wide, allowing the squirrels to glide from one side of the transmission line to the other. Our technical solutions make green corridors possible,” says Eeva Paitula, Expert, Transmission Line Routing at Fingrid.
The technical solutions allow transmission line towers to be built closer to each other than usual. By reducing the spans between towers to 200 metres from the typical range of 250–350 metres, the conductors can be high enough to allow trees to grow naturally, forming a green corridor without any electrical safety concerns.
“The green corridors are treated to form a continuum of young trees of different heights. When trees grow to a height of 10 metres, they are felled and left in the terrain to decompose, thereby promoting biodiversity.”
Terrain surveys and land expropriation
The first green corridors will be established on the transmission line route between Kristinestad and Nokia. Construction is due to begin in 2026, and the 170-kilometre line may have up to 6 green corridors.
“The green corridors will be near the flying squirrel habitats identified by an environmental consultant. The locations are also influenced by surveys based on habitat models from the Natural Resources Institute Finland and the Flying Squirrel LIFE project,” says Paitula.
For green corridors, Fingrid expropriates the right of ownership of the land.
Fingrid is normally assigned the right of use of the land under transmission lines. However, for green corridors, Fingrid expropriates the right of ownership of the land to ensure the preservation and treatment of trees in the green corridor in line with the objectives of protecting the flying squirrel.
Green corridors are built specifically for flying squirrels, but other animals can also benefit from them.
