Plants playing at home: Advantage of native plant seeds for ski slope revegetation in the French Pyrenees

Abstract

Machine levelling for the creation or maintenance of ski slopes is a major source of disturbance in high elevation ecosystems. Traditional, exogenous seed mixtures can help restoring plant cover and mitigate soil erosion, but they comprise species that are not ecologically adapted to high elevation conditions. Here, the use of local seed mixtures, harvested at nearby sites, was compared to that of exogenous seed mixtures for revegetation of three machine-graded ski runs with different soil conditions in the French Pyrenees. The plant cover, biomasses and associated soil microbial activity were recorded for four years following seeding. The results showed that the establishment of the plant cover was highly dependent of the soil conditions and strongly differed between paired plots that had received local or exogenous seed mixtures. In both seed treatments, some Poaceae dominated the plant cover, allowing the settlement of several spontaneous native species. But the plant cover established more rapidly and more densely, and included a larger cover of target, native species after seeding with local compared to exogenous seed mixtures.