The Alps are getting warmer. Since 1950, the Alps have already seen a 2°C rise in temperature. At the same time, meteorological hazards such as early snow removal, droughts and late frost events are becoming more frequent. This has an impact on the landscape and biodiversity, as well as on the development and productivity of vegetation. Difficulties can then arise on the alpages for the management of the herds during the summer transhumance.
A first step towards adaptation is to become aware of the climatic risk on alpages. The “Alpages Sentinelles” programme was set up in the wake of the repeated droughts in the early 2000s in order to assess the phenomena at work and anticipate the need for adaptation in these areas. This collaborative research-action programme aims to produce and disseminate knowledge on the evolution of the alpages and provide tools for their practitioners.
It is in this context that INRAE scientists, in association with Météo France, have developed a tool to visualise the evolution of the agro-climatic context of alpages under the effect of climate change. This freely available tool consists of a web interface that displays the climatic profile of more than 2,700 alpages in the French Alps. It provides users with indicators in the form of time-series starting in the 1960s, so that they can compare their values in a given year with reference periods. The data made available online are based on a reference data set produced by Météo-France over a historical reference period (SAFRAN reanalysis).
It is thus possible to monitor the evolution of key indicators for understanding climatic evolutions, such as the conditions at the onset of the vegetation growing season in the alpages (in particular early snow removal, frost and temperatures). Other parameters can be monitored, highlighting new constraints for pastoral management in alpages. One can thus find the date of reaching certain thresholds of vegetation development according to the temperature accumulation, which gives indications as to the moment from which it is possible to bring animals up to the alpages. Thanks to this tool, one can note a gain in earliness of about fifteen days on average over the recent period (1991-2018) compared to the historical reference period (1960-1990) on the scale of the Alps, but which is also subject to strong interannual variability.
The challenge that accompanies the implementation of this new tool is its appropriation by the actors. The deployment of the vulnerability assessment of alpages to climate change is essential for all stakeholders in order to become aware of and identify the adaptation practices and strategies to be implemented according to the specific characteristics of each alpage.
Firstly, it will be necessary to complete the current tool by integrating areas in the Prealps and the most Mediterranean zone of the Alps that are not yet covered. Secondly, the challenge for the future of the alpages will be to move beyond the observation stage in order to provide the means to anticipate adaptation needs on the basis of climate projections up to the end of the century and according to different greenhouse gas emission scenarios, using a set of data produced by Météo-France on the future climate and adapted to mountain areas.
What are alpages?
Alpages are high altitude areas used for their summer forage resource by herds of domestic herbivores that migrate from the valleys or the plains. These areas offer a spontaneous pastoral resource, often herbaceous, sometimes shrubby and/or wooded. They are used exclusively for grazing (no mechanisation possible). They are multifunctional areas, emblematic of the mountains. In addition to their economic and agricultural role, they are recognised for their biodiversity and cultural heritage and contribute to the tourist identity of the area. The pastoral management of these areas is a determining factor in maintaining biodiversity and this multifunctionality.
Deléglise C., François H., Dodier H., Crouzat E., Samacoïts R., Morin S., Bray F., Nettier B. (2022) Agro-climatic profiles of summer mountain pastures in the French Alps : towards a monitoring tool to contribute to climate risk assessment. Agronomy for Sustainable Development. https://doi.org/10.1007/s13593-022-00776-6