Above Biasca lies the chestnut forest of Santa Petronilla – a historically and ecologically valuable habitat.

Sweet chestnut trees (Castanea sativa) have been cultivated here for centuries. The light-filled, open forest structures of these "selvae" developed through regular management and were once central supply areas for humans and animals. Today, this special cultural landscape is threatened with disappearance: Without care, blackberries, bracken , and other competitive woody plants grow back, densifying the undergrowth and preventing the regeneration of the chestnut trees. This results in the loss of valuable habitats for heat-loving species such as lizards, wild bees, bats, and various fungi.

The work includes cutting back undergrowth, removing invasive species, clearing old chestnut trees, and clearing up branches.

The use of this plantation will restore the light forest structure typical of chestnut trees – and with it a piece of living Ticino history.