The cross-country ski trails in the Pertuyzat sector are bordered by spruce trees in perfect health which is not the case everywhere in Auvergne where the species was locally weakened by the drought of summer 2018 as well as autumnal and winter conditions which did not allow the water recharging of the soil. More sensitive to climatic disturbances than the fir, the spruce is then attacked by the bark beetle, a pest whose proliferation is favoured by global warming.