The standing stone of Trépaloup

Inaugurated in 1824, the meteorological observatory was built on the initiative of Georges Fabre, one of the pioneers of the reforestation of Mont Aigoual. His work with the botanist Charles Flahault enabled the creation of the arboretum of L’Hort de Dieu. The first meteorological data were gathered by agents from the French National Water and Forestry Commission. Since 1943, the observatory has been managed by the National Meteorological Office. It is France’s last mountain weather station that is inhabited year-round.  

Here, only species with a short reproductive cycle can settle due to the frequently glacial climate. The heath has been invaded by heather and mountain pine. This zone is barely wooded due to the violent winds and is comparable to subalpine vegetation, consisting of short-grass prairies and heather and blueberry moor. It is sometimes called pseudo-alpine.

At the pass stands a schist menhir (standing stone). To the north, in Trépaloup ravine, hewn flint implements bear witness to a human presence in the region since prehistoric times. Palynological analyses (studies of pollen fossilised in peatbogs) have allowed scientists to piece together the plant life on Mont Aigoual from 8,000 to 5,000 BC. Pine predominated, accompanied by birch and hazelnut. Then pine populations gradually diminished. The damp climate warmed up, favouring the spread of oak and hazelnut. Finally, the increased damp and cloud cover at altitude allowed fir and beech to develop. From the end of the first century BC, the substantial percentage of grasses shows that forest had receded in favour of pasture and prairies. This was the start of the great deforestation.