Around Polset

The climate and local materials have brought about a special know-how in the construction of buildings, which are built on an East-West orientation, supported and well hung on the slope. The buildings take advantage of existing boulders and natural hollows to provide shelter from avalanches and the wind. In Polset, an interesting fact is that the builders combined both stone and wood. Beams embedded in the masonry form a chain that surround the building to strengthen its cohesion.

The Vanoise is also an agricultural land. This pasture is currently used by sheep in the summer. These sheep are transhumant originating from the south of France. This pastoral vocation is old and the chalets are proof of it. Carrying on this activity is important for keeping the open spaces that are habitats for many species.

Thanks to their southern exposure and their steep declivity, the slopes above the hamlet of Polset are replete with chamois and ibex during the winter months. The steep terrain and its predominantly southern exposure facilitate the clearance of snow and allow the ungulates to quickly find the grass that is vital to their winter survival.

Large, generally pale yellow with black stripes that cut through its wings, it is easy to spot even in full flight. It tends to hover in flight. A beautiful butterfly that can’t be missed, it loves warm, herbaceous and slightly bushy areas with rocky outcrops. The Polset valley has a wealth of assets to welcome this butterfly.

First stop to observe the “stones”. Strata are visible, so we have a sedimentary rock. 300 million years ago a chain of mountains covered what was to become France. Eroded, it left space for a warm, shallow sea. At the bottom of this sea, the sediments were deposited and our rock began to form between -240 and -233 million years. In 7 million years a rock thickness of about 150 m was created. We can only see about 5 metres here. It is grey limestone. The uplift of the Alps 80 million years ago moved and carried this rock to where we walk today.

Although it is better maintained than agriculture which has been challenged by the slope and fragmentation of the land parcels, pastoralism has receded. The grasslands retreat before the green alders and spruces, while the on-site mechanical installations, such as the old churn, made mobile or taken further down the mountains within streamlined fixed operating units, are disappearing.

Look at the rocky slabs on the left as you descend the track. These are undulated like the sandy beaches by the sea. Not surprisingly, it was actually the sand from a beach that gave birth to this rock. Its undulations have remained intact despite its transformation into rock. Several million years ago, this was the site of a beach.

Ÿou are not witnessing a pile-up of vehicles but a pile-up of two geological formations of different ages. Looking north, on your left, is the coal-shale part of the Vanoise with dark rocky cliffs (rocks dating from -360 to -295 million years). To the left, beyond the summit of the Schwarzhorn is the “crystalline” Vanoise, which is not visible from this point. The Schwarzhorn is located between these two formations.

This water intake collects part of the waters of the St. Bernard rivulet, which come from the melting of the Chavière glacier. Once collected, this water is sent to the Plan d´Aval reservoir several kilometres away by means of underground pipes. The construction of these tunnels required an enormous amount of work. The water stored at Plan d´Aval is then sent to the Avrieux hydrœlectric power production site.

The Vanoise has about 200 species of birds. This species inhabits the area between the mountain and sub-alpine environment and on the edge of the forest. It particularly likes coniferous forests. Polset is therefore the ideal environment. Its name evokes the colour green. The Citril comes from Provençal which derives from Verduron. The bird is predominantly green with yellow plumage. The Citril finch observing altitudinal seasonal migrations. They are a delight to find in springtime in Polset.

Several species of softwood populate the Polset valley. They are best identified by looking at their needles: If they are long and in ascicles of five then it is a cembro pine. If they are grouped into ascicles of 30 to 50 pale green needles and soft to the touch, then you are looking at a larch tree. The Scots pine has needles grouped into ascicles of two and an orange trunk at the top, or salmon-pink some would say. The silver fir has dark-green needles with two small white grooves on the underside which resemble ski tracks.