Cas pratique : Utilisation du système d'information géographique comme outil de gestion de zones humides d'altitude : le cas du domaine skiable de Val Thorens

Dans quelle mesure l’utilisation d’un système d’information géographique peut-elle aider à la gestion des zones humides de montagne ? Quel est l’intérêt d’un outil de cartographie dans la définition des mesures de gestion et de restauration ? Premiers éléments de réponse et perspectives d’utilisation pour les gestionnaires des zones humides d’altitude du domaine skiable de Val Thorens

Transplanting success of two alpine plant species in combination with mulching during restoration of a high-elevation peatland

International audienceMany high-elevation wetlands have been degraded by activities related to the skiing industry. However, few studies exist on their restoration in this harsh environment. From 2010 to 2017, we set up an experiment on a degraded bog located at 2500 m within the ski resort of Val-Thorens (France). We tested (1) if transplanting two sedge species, Trichophorum cespitosum and Eriophorum scheuchzeri effectively helped to initiate the restoration of the bog vegetation and (2) if different planting combinations of the species under different mulch treatments affected transplant survival and cover. After stabilising the bare peat with wood fascines and installed weirs in the incised gully that drained the bog, we planted tussocks of T. cespitosum and ramets of E. scheuchzeri, each alone or in mixture. We used straw mulch or a "biomulch" made of live shoots of Polytrichum moss. After a slight increase the first 2 years, the number of E. scheuchzeri ramets decreased continuously in all treatments and reached zero in 2016. T. cespitosum had a low mortality in all treatments; its annual survival rate and cover were significantly higher with biomulch. Because of strong winds and snow action, all the straw was removed after 2 years while the biomulch cover remained between 10 and 25% from the third to the fifth year then was close to zero from 2016. Nevertheless, this low cover seemed sufficient to favour the survival and growth of T. cespitosum. In 2017, bare soil was lower in all treatments with biomulch and T. cespitosum. This treatment appears to be the best restoration option, but it is likely that more than 7 to 10 years will be required to establish adequate plant cover at degraded high-elevation sites

Cas pratique : Utilisation du système d'information géographique comme outil de gestion de zones humides d'altitude : le cas du domaine skiable de Val Thorens

Dans quelle mesure l’utilisation d’un système d’information géographique peut-elle aider à la gestion des zones humides de montagne ? Quel est l’intérêt d’un outil de cartographie dans la définition des mesures de gestion et de restauration ? Premiers éléments de réponse et perspectives d’utilisation pour les gestionnaires des zones humides d’altitude du domaine skiable de Val Thorens

From repairing the damaged landscape to restoration project

The study adopts an empirical sociological approach to analyse how the objectives behind the revegetation of ski trails and runs in the French alpine resort of Alpe d’Huez have evolved since the 1970s. A revegetation programme was first introduced to repair the scars left by the works conducted to equip the resort with infrastructures, and then, over time, it became a more complex restoration project. At first, revegetation techniques were developed to fight soil erosion, but soon also became associated with the idea of “turning the mountain green again”. Now, 40 years later, revegetation is aimed at restoring both a natural ecosystem and a cultural landscape. The ski resort’s managers, local farmers, technicians, and those conducting research in the area share a common desire to promote autochthony, which in some cases runs the risk of reproducing folklore. Far from adopting an overriding ethical perspective, the study suggests that the area’s physical characteristics, specific history and configuration of local actors have shaped and continue to shape both the manner in which ecological restoration is implemented, through political choices and technical decisions, and the debates it gives rise to. The study concludes by examining the specificity of the findings for Alpe d’Huez and discussing their validity for other alpine ski resorts.<br>A partir d’une approche sociologique empirique, ce texte propose une analyse de la mise en œuvre de la revégétalisation sur la station de l’Alpe d’Huez depuis les années 1970. Il montre comment la revégétalisation est passée d’un objectif de réparation des cicatrices provoquées par les aménagements à une entreprise plus complexe de restauration. S’il s’agissait au départ de répondre à un objectif technique de lutte contre l’érosion, la revégétalisation a pris rapidement une tournure paysagère (reverdissement) ; elle a ensuite été pensée dans une perspective de restauration des écosystèmes ainsi que de restauration d’un paysage culturel « typique ». Aujourd’hui, gestionnaires de la station, techniciens, agriculteurs et chercheurs impliqués partagent un désir d’autochtonie qui touche dans certains cas à la foklorisation. Loin d’une perspective éthique surplombante, cette étude suggère ainsi comment les caractéristiques physiques du territoire, son histoire et la configuration des acteurs locaux informent largement les arbitrages et les choix techniques qui président à la restauration écologique, ainsi que les débats qui l’entourent. En conclusion, nous discutons de la spécificité de nos résultats et de leur validité pour d’autres stations alpines

De la réparation à la restauration

In this article, we analysed how the objectives behind the revegetation of ski trails have evolved since the 1970’s. Our approach was based on a sociological survey. We show that the revegetation was first launched in order to repair the scars due to the works and to the infrastructures on the resort and then became, over time, a more complex restoration project. At first, revegetation techniques were developed to fight ground erosion. Soon, it was also associated with the idea of “turning the mountain green again”. Now, 40 years later, it aims at restoring both a natural ecosystem and a cultural landscape. The ski resort’s managers, the technicians, the farmers, and the concerned researchers share a common wish for autochthony, which sometimes is close to folklorisation. Far from an ethical and general perspective, this study suggests that the physical characteristics of the territory, its specific history and its actors’ configuration shape the way ecological restoration is locally performed through political choices and technical decisions, as well as the debates which are at stake. As a conclusion, we point the specificity of our results concerning l’Alpe d’Huez and discuss their validity for other alpine ski resorts

Environmental risks and impacts of mountain reservoirs for artificial snow production in a context of climate change

Mountain reservoirs are hydraulic structures established in recreational mountain resorts designed to provide a water reserve mainly used for the production of artificial snow. Their siting in high-altitude zones makes them highly specific reservoirs subjected to and inducing risks and impacts on their human and ecological environment. Based on in-depth bibliographic and field research, Cemagref has launched a study on mountain reservoirs. The present article aims to establish the current state of the risks related to mountain reservoirs and their impacts on the environment, placing the development of mountain reservoirs in their societal, social, and environmental contexts. It will then develop mountain reservoir risks and impacts, focusing on the specific risks and uncertainties to which these structures are exposed, and the different environmental impacts related to the construction and management of these reservoirs

Risques et impacts environnementaux des retenues d’altitude pour la production de neige de culture dans un contexte de changement climatique

Mountain reservoirs are hydraulic structures implanted in recreational mountain resorts designed to provide a water reserve mainly used for the production of artificial snow. Their implantation in high-altitude zones makes them highly specific reservoirs subjected to and inducing risks and impacts on their human and ecological environment. Based on in-depth bibliographic and field research, Cemagref has launched a study on mountain reservoirs. The present article aims to establish the current state of the risks related to mountain reservoirs and their impacts on the environment, placing the development of mountain reservoirs in their societal, social, and environmental contexts. It will then develop mountain reservoir risks and impacts, focusing on the specific risks and uncertainties to which these structures are exposed, and the different environmental impacts related to the construction and management of these reservoirs