Walking along the nature trail (starting at Chanavey), it is possible to come across different points of interest indicated by descriptive panels that allow you to find out more about Rhêmes-Notre-Damey from a morphological, naturalistic, ethnographic point of view...
Human settlements in the valley have always been affected by demographic patterns, catastrophic events (landslides, avalanches, floods...), acts of war and natural cycles. As a matter of fact, the climate has changed considerably, if one thinks that the mountain pasture of Fos (2,067 m) was once inhabited all year round. The permanently inhabited villages sprung up along the stream, where the terrain is flatter and the risk of avalanches lower. The size of the settlements varies depending on the potential to make a living, what was not possible to grow locally was produced in the valley floor at Saint-Pierre. A fundamental concept emerges from this: the inhabitants of this area were perpetually migrating between the properties of the valley floor and high pastures in summer.
The morphology of an Alpine valley
The valley was shaped by glacial erosion, which up to 12,000 years ago occupied the whole area, from Mont Blanc to Ivrea, with a thickness greater than 1000 m. Looking at the valley you can see the "U" profile with a flat bottom and steep sides, the "glacial cirques" that make up the valley heads, and the "steps of confluence" where the action of the main glacier is more evident. Gradually, the streams accumulated alluvial deposits in the valley bottom and "alluvial fans" coming from the side valleys. Landslides have contributed to reforming the area with the accumulation of "detritus layers and cones".
Sunny rocky ridges, on the opposite side, are overwintering areas for the chamois and ibex. During the summer season we find them at high altitudes, while in the late autumn they move to the exposed rocky walls to the south, to overwinter until the beginning of summer. These ridges provide them with shelter from the weather and avalanches, the snow-free grassy areas allowing them to feed during the winter months. In May the green grass draws them close to the villages.
Alongside the rocky faces you can see a number of birds flying. Binoculars can help you tell apart the crows, black in colour, from birds of prey, lighter in colour. The most common are the Common Raven, the Alpine Cough and Red-billed Cough and the Black Crow. The most prominent bird of prey is the Golden Eagle, whose main prey is the marmot. Smaller in size is the Kestrel, with its long tail and wings that end in a tip, and the Sparrowhawk, with more rounded wings. Recent years have seen the reintroduction of the Bearded Vulture, a large vulture with a cuneiform tail.
The "giant" plants. If you look at the slopes near springs and the edges of the streams you may notice herbaceous plants of considerable size for such an Alpine environment. This is why they are called "Megaforbie", species include Woodland Geranium (Geranium sylvaticum), Maiden Sorrel (Rumex alpestris), Alpine Cabbage (Adenostyles alliariare) and Masterwort (Peucedanum ostruthium).
Rural architecture was linked to the agricultural use of the land. In addition to the family home, there was a need for shelter for animals, foodstuffs and hay, and places for processing farming produce: the kitchen (mèison) with a big fireplace for making cheeses and a covered area (grandzoe) for threshing cereals. The barn and the house were made of stone, while the attic area, used as a hayloft, was partially close by a wooden plank in order to ventilate it and prevent it from setting alight.
A The first house you meet in Orellier is telling for the top of the roof which is parallel to ridge of the mountain and the two very elongated sides almost touching the ground. This system reduced the risk of damage when hit by an avalanche.
B On entering the village there is a small stone and wood barn, now transformed into a dwelling. On top of the stone base there is a wooden structure made with planks and protected from the ground. The lower floor was used as a kitchen, storeroom or barn, while the two upper floors were used for all the family belongings.
C In the first clearing on the right you notice an example of rural architecture on two floors and with a double-gabled roof. The house includes a barn, the dwelling (identifiable by smokestacks) and the hayloft in which the area for threshing cereals was often located.
D Along the trail to left of the Park's shed lies the shared dairy, which was used by the whole community for processing milk. Inside is a huge fireplace with a revolving fork on which were hung the cauldrons and other tools for the processing. The lintel of the door bears the date of 1924.
E Just beyond the dairy is a dwelling with covered storeroom on the ground floor for the cart. This means was used for transporting materials because of the lack of slopes in the valley floor.
F Just after it is easy to spot a house with a cylindrical pillar. This had a number of uses: its covered passageway was a place for the cart and protected it from bad weather. The part in stone was for the barn, the dwelling and the hayloft, well ventilated by wooden slits. The granary was also in wood.
Geology's vastness of time force us to use our imagination to understand the phenomena which have led to the current appearance of the mountains. Rocks different in their nature and origin are twisted on top of each other. Looking at the picture below you can see the different layers of the continental shelf alternating with materials from the bottom of the ocean and shallow seas.
These complex structures are due to the effects of the huge pressures that led to the rise of the Alps. More than 100 million years ago the land masses of Europe and Africa came together closing the ancient Tedide Ocean that once separated them, folding the Earth's crust. The image below shows the ancient prealpine geography.
The transition from the former appearance of the past to that we see today involved various geological phenomena. The rocks visible nowadays exposed to erosion were pushed to depths of tens of kilometres and subjected to enormous pressure and temperature increases. The original structure and mineralogy of the rocks has changed, giving rise to the phenomenon of metamorphism.
The "alneto" (green subalpine association of vegetation) is a dense area formed mainly by the Green Alder and can be likened to a rainforest due to a number of its features:
Green Alder (Alnus viridis) is a shrub, even a couple of metres tall, with branches that form impenetrable entanglements. It is accompanied by other shrubs, including several species of Willow, Blue Chervil and Rock Currants, rather rare in the Alps, but which has found a favourable habitat in the valley.
One of the characteristic shrubs is the Mountain Ash, with its red berries which are much loved by birds and therefore used by bird-hunters. The herbaceous layer is composed of the above-mentioned "megaforbie", along with uncommon species such as Tansy-leaved Rocket, Martagon Lily and French Meadow-rue. Globeflowers stand out in the grassy fields of these mountain lands.
The areas of upland grassland are part of the Alpine pasture of Lo Botse and the village of Broillat. These fields are cultivated as meadow-pasture, mowed at the end of July and used for livestock grazing in autumn. These areas are bordered by coniferous forests and are a habitat for many animal species.
Cow pats provide food for dung beetles, which are very useful in breaking down the manure and making the soil fertile and suitable for herbaceous growth. There are numerous varieties of Lepidotteri (butterflies): Mountain Apollo (Parnassius apollo), Orange Tip (Anthocaris cardamides), Clouded Yellows, Cabbage Whites, Gossamar-winged, Brush-footed, Burnet Moths and Hawk Moths.
Gathering polleN from the flowers are also various Hymenoptera such as Bumble Bees, Wild Bees, Flies and various species of Beetles. The dense vegetation is also home to some invertebrates such as molluscs: Slugs and Snails, including the large Helix with its hazelnut shell.
Predators and prey
Moving up the food chain, birds feed on these insects and invertebrates. The meadows and trees are the hunting grounds of the Whinchat and the Black Redstart. Chaffinch and Serins feed on grain, while the Black Crow is omnivorous. Among the small mammals there are the Wood Mouse, the Water Vole and the Shrew. At twilight and night, we can see the Brown Hare and the Mountain Hare, whose fur turns completely white in winter. Among the carnivores, but hard to see, there are the Weasel, the Stoat, the Beech Marten, the Badger and the Fox.
This area is characterised by a spring, sourced by the water from the rocks and detritus permeable deposits of the mountainous side, giving life to a number of different environments: streams, shallow puddles, ponds and the small lake of Pellaud below.
This mixture of stagnant and flowing water is the ideal habitat for several species of animals. Between the stones are the larvae of macroinvertebrates, insects that help stabilise the purity of the water. They transform into Dragonflies, Mayflies, Stoneflies, Caddisflies and Flies. It is interesting to watch the Diving beetles, small dark beetles that swim underwater thanks to the rowing hair on the back legs; when they resurface, they store air bubbles beneath the wing casing for underwater breathing.
Mammals include the Water Shrew, able to swim easily on the bottom of the stream in search of food thanks to the fringes of stiff hair on the tail that it uses like fins. It eats its own weight in food every day.
Another interesting animal that has adapted to water life is the Dipper, which walks underwater to get food and builds its nest along the banks at surface level or behind waterfalls. Other birds include the White Wagtail and the Grey Wagtail, recognisable by their long tails, the Wren, small and brown with a short raised tail, the Little Leaf Warbler, a feathery cotton ball, brown and green in colour.
A typical amphibian of these places is the Common Frog. It is possible to see its tadpoles swimming in large numbers, they grow and develop during a summer, but it takes 4-5 years to reach the reproductive age.
The edges of the ponds are always soaked with water, favouring the development of hydrophytic vegetation, the most striking being Cottongrass (Eriophorum angustifolium) and Speedwell. Others, more abundant, but smaller in size are the Sedges, the Rushes and the Firefly Grass.
The small lake of Pellaud was formed following a landslide of the glacial cirque bearing the same name of the east wall of G. Rousse. The accumulation of huge blocks created a barrier diverting the flow of the stream and forming an upstream flood plain. The bottom of the lake consists of large blocks clogged with limescale material and therefore permeable, resulting in water leakage. In the 1980s, the basin ran dry due to drought, and "cracks" opened on the bottom of the lake, preventing filling even if sufficient water arrived. Waterproofing works allowed this small lake to be reborn.
Landslides mould the landscape
The shape of Alpine valleys, in addition to the glacial action, is also due to the landslides of the steep slopes that, descending to the valley, form slopes, debris cones, and, in the case with lake Pellaud, alluvial, even marshy plains, with peat deposits.
Landslides sometimes involve entire mountain sides, causing the a gradual collapse towards the valley, along sloping surfaces even hundreds of metres deep. Shifting out focus northwest it is possible to see the Chateau-Quelet rocky canyon formed by one such phenomena that affects the downstream slope of the junction of the Sort and Entrelor valleys. Similar situations are called paleophrenic, since they are inactive, dating back to the period of the last glaciation (10,000 years ago). The abrupt retreat of the ice (here even 1000 m thick) caused a decompression and the collapse of the more fractured slopes.
The Pellaud mill, which was uilt as a grinder for cereals, was transformed into a power plant in 1921, with the creation of the Société Coopérative Electrique du Lé. The plaque on the facade bears the name of the creator, Henry Bristin.
As soon as you enter Pellaud, there is a small building with a porch: it is the village oven, a communal structure where families would take turns baking rye, usually once a year at the start of winter. Communal ovens are typical throughout the Aosta Valley, a communal oven could back from 30 to 120 loaves at a time. The Pellaud oven is one of the few that is still working and continues to play a role gathering the community together to this day.
A typical part of the Valdostan culinary tradition, it is called "Pan Ner" (Black Bread). It is obtained from a dough of rye and wheat, with a rounded shape and a brown crust. The bread was dried on special racks, "ratelé", placed in haylofts and ate throughout the year.
You now enter the area of a larch forest, an open and bright wood, with a teeming undergrowth. The Larch (Larix decidua) is distinguished from the other conifers for its short, soft needles, light green colour, arranged in bunches of 20-30; in autumn, unique among the conifers of the Alps, the needles turn yellow and fall; the bark is rough and very thick. Out of the rather uncommon tall trees, the stone pines are distinguishable for their longer and darker needles, arranged in bunches of five. The large oval shaped pine cones produce numerous edible pine nuts.
The shrubs of the undergrowth
There are numerous species, such as the Bilberry (Vaccinium myrtillus), with vivid red flowers and delicious black-and-blueish berries; Lingonberry (Vaccinium vitis-idaea) with white flowers streaked in red that turn into red berries from which a tasty jam is made; Rhododendron (Rhododendro ferrugineum), with flowers ranging from red to white, evergreen and on the underside of the leaves they have a rusty colour from which the scientific name derives; the common Juniper, an evergreen shrub-conifer with very sharp needles, with its very aromatic blue berries used to be produce liquors.
Just past a clearing in the larch forest, the trail becomes more cramped and narrow and passes between two rocks; here you can see on the surface of the large boulder to the right some grey, yellowish, white "veneers"... these are lichens. They are a plant-like organism present on the trunks and branches of larches, on the ground, on mosses and on the rocks such as the one we can see right now. Lichens play a very important ecological function (pioneering) on rocks; they prepare the surfaces for the establishment of other forms of vegetation, which otherwise could not grow directly on the rock.
What are lichens?
Lichens are an association, called symbiosis, between two very different organisms: an algae (and/or cyanobacteria) and a fungus. The latter provides the algae with the protection and what is need to photosynthesis, from which the fungus itself benefits. In the case of lichens, the resulting organism does not resemble any of the two original components and, thanks to the symbiosis, lichens may grow where neither algae nor fungus could survive. This association is particularly successful in Alpine environments, where environmental, climatic and nutritional conditions are so adverse.
The Red Wood Ant lives in these woods and builds nests using materials found in the undergrowth. The large heap is usually built on a coniferous stump, with the nest inside consisting of tunnels and rooms for storing food and breeding offspring. The anthill is waterproof and the various entrances can be closed in case of danger. Each colony can have anything from 200,000 to one million individuals divided into social caste: the big queen lays the eggs; the males, called drones, are there for reproduction, and come out of the anthill together with the queen at the beginning of the summer; the workers carry out the tasks related to the construction of the nest, the feeding of the offspring and the search for food.
A discreet presence
In order to discover the presence of other animals, we need to look all around for small signs. Underneath the bark of the dead logs you can find the larvae of Longhorn Beetles, xylophagous insects (that feed on the wood). The top soil consisting of pine needles and other plant remnants hides microorganisms such as Springtails, Mites and Ticks, Molluscs and Worms.
Holes with a diameter of 3-4 cm, food remains and tunnels signal the presence of Mice and Voles. Other food remains such as nibbled pine cones come from Squirrels and Dormice; dug out anthills are the work of the Badger and the Green Woodpecker; there are few traces left by carnivores, such as excrement or food remains from Foxes, Weasels, Stoats, Beech Martens and Martens.
Your ears can pick up the song and presence of numerous passerines like the Chaffinch, the Goldfinch, the Fieldfare, the various Tits, the Goldcrest, the Crossbill and the Treecreeper. Drumming on tree trunks is a common trait of the Woodpeckers, the most prevalent being the Red Woodpecker and the rare Black Woodpecker. They drum, tap and drill into the wood searching for the xylophagous insects that live in the tunnels. Woodpeckers therefore keep the number of these insects under control that could otherwise cause serious damage to the trees.
Among the nocturnal birds of prey, the Little Owl occupies the nests carved out in the trunks and then abandoned by Black Woodpeckers; the Tawny Owl lives in the densest areas of the woods or on rocky cliffs.
The narrow alluvial plain we are in is connected to the Pellaud landslide (point 8). It was formed following the regular flooding of Dora di Rhemes, which caused the gradual accumulation of gravel and sand. Alpine streams have considerable fluctuations in water flow, conditioned by the melting of snow in the early summer and the intense rainfall that rapidly flows downstream from steep rocky slopes. When the two phenomena come together (often at the beginning and end of the summer), the result can be catastrophic, with erosion of the banks and flooding in flat areas.