Revegetation of the Vernie Rouge ski slope in the Alps

National Id
Site name
The Vernie-Rouge trail.
In the ski resort of Saint-Léger-les-Mélèze, a ski slope carved out by remodeling work was revegetated to reduce erosion, increase snow retention on the slope, improve the resort's landscape integration and allow grazing activity on the slope in summer. Vegetation restoration was done by the so-called "green hay" technique, which consists of seeding the area with hay previously harvested nearby. The seed bank provided by this technique makes it possible to encourage the establishment of a diverse range of species adapted to the local context. This restoration project was part of the "Sem' les Alpes" programme, aimed at developing vegetation techniques adapted to alpine meadows.
The in-depth description of the case study
Location description
The Vernie-Rouge trail is located in the Saint-Léger-Les-Mélèze resort, in the adhesion zone of the Les Ecrins national park. Facing North, it is located at an altitude of 1300-1500 m above sea level. It is identified as mountain hay meadow (priority habitats) by the EUNIS habitat classification. It has been remodeled in 2015, leading to a nude soil which was rapidly eroded by rain events and revegetalisation with commercial seeds have not succeeded.
Provence-Alpes-Côte d'Azur
RBD code
FRD-Le Rhône et les cours d'eau côtiers méditerranéens
NWRM(s) implemented in the case study
Light or indepth?
Monitoring parameters
Botanical inventory of donor grassland
Before mowing, the national alpine botanical conservatory (CBNA) conducted a comprehensive inventory of the hay meadow used to produce green hay, in order to assess the establishment of herbaceous species in the restored meadow.
Botanical monitoring of the restored site
Vegetation is monitored annually in 15 quadrants of 50 centimeters each side, distributed over a square of 10 meters each side along 3 transects (5 quadrants per transect). All plant species present are recorded, as well as the cover of vegetation and coarse elements (>2 cm). The frequency of species presence at the area scale, specific richness, and percentage of target species are calculated from these data.
Biophysical impact assessement method
Comparison with control site
Project scale
Application scale
Field Scale
Installation date
Area (ha)
0.27 ha
Favourable preconditions
The restoration of natural grasslands on ski slopes reduces erosion while improving the landscape and allowing agricultural use during the summer months. The use of local green hay should encourage the establishment of vegetation and is more interesting for biodiversity than commercial seeds.
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Design consultation activity
Activity stage Key issues Name Comments
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Others (please specify in column H)
Initiation of the measure
Municipality of Saint Léger les Mélèzes
Research institute / University
Conservatoire botanique national alpin (CBNA) (National Alpine Botanical Conservatory)
Key lessons
Although no specific monitoring has been put in place, the ski resort promoter reported an improved situation as regards erosion and for maintenance of the snowpack, both primary objectives of the project. The re vegetalisation with green hay is more efficient than commercial seeds mixture with plants more adapted to local conditions and more efficient than dry hay in which part of the seeds are lost or not germinating. It requires however an adequate monitoring of the hay source to allow maximum amount of seed species of good quality and more manual work to spread the hay. The hay also provides organic material, useful for the first years of the growing meadow. After 2 years, the meadow includes 73% of the targeted species, as compared to 53% with commercial seed mixture: local source allow having a seed mixture adapted to local conditions.
Success factor(s)
Success factor type Success factor role Comments
Attitude of decision makers
main factor

The main opportunity was the involvement and motivation of the municipality of Saint Léger les Mélèzes to participate in the Sem' les Alpes programme. The animation and consultation work carried out in this programme has proved to be very important for the development of revegetation by alternative methods.

Financing type Comments
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Driver type Driver role Comments
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Policy description
Ski resorts commonly face erosion problems on their ski slopes, which prevent the establishment of herbaceous vegetation. The absence of vegetation reduces the snowpack's shelf life and affects the quality of the landscape during the summer months.
Many ski resorts are therefore carrying out revegetation operations on their slopes in order to stabilize the soil on the ski slopes and limit erosion. However, revegetation is generally carried out with exogenous seeds that are not fully suited for local conditions and biodiversity, and that also have a low species diversity. The runway has been remodeled, with its ground exposed. At the same time, a retention basin was dug upstream of the runway, causing a lot of soil material to be deposited on the runway. These materials were removed at the first rainfall, which made the ski slope very stony. Attempts to vegetate the ski slope following the work did not work, and it remained bare. The objectives of the prairie revegetation were to improve snow cover conservation and control erosion, while allowing the ski slope to be landscaped and grazed in summer. It was not grazed on the first 2 years to allow its correct rooting and installation.
Policy target
Target purpose
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Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
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Requirement directive Specification
Information on Ecosystem improved biodiversity
After 2 years of revegetation, 73% of the procession is composed of target species (species typical of hay meadows), compared to 53% with the traditional method
Information on runoff reduction
The year after restoration, erosion was observed in the area planted with commercial seeds, unlike the area planted with green hay. According to the Mayor of the municipality and the operator of the resort, the snow on this plot holds better than it did before it was planted.


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