Riserva Naturale Valle del Freddo

The Reserve

Valle del Freddo was born as a "biotope" of Regione Lombardia on 3rd December 1981. It lies in the territory of the Municipality of Solto Collina at 350-700 m of altitude and covers about 70 ha. The Reserve is characterized by a particular microclimatic phenomenon enabling the growth of high-mountain flora. The first botanist who explored Valle del Freddo was Guido Isnenghi who in 1939, while he was passing through Piangaiano, noticed an edelweiss on the hat of a hunter, who told him he picked it up in the area where today there is the Reserve. The botanist went and explored the area and found there botanical species which usually grow only at higher altitudes. The growth of these species, unusual for the area, is caused by the presence of the cold holes or "mouths" from which icy air comes out. Since then, several researchers and experts have been studying this phenomenon. In '62 Luigi Fenaroli published the first collection of researches carried out in the valley, confirming the presence of about 160 botanic species, out of which without a doubt 24 high-mountain species. In '53 and '73 two quarries threatening to destroy Valle del Freddo and its particular phenomenon were opened. When the second quarry was opened in 1973, a local association (N.E.A.V.C.) was born with the aim to safeguard the valley. Thanks to its resolution and the sensitivity of some public authorities, the G.R.L. definitively closed the quarries in October 1976.
Afterwards, with the Regional Law no. 86/83 Valle del Freddo became a Nature Reserve with the aim to safeguard its geological, vegetal, and zoological heritage.

Geology

The origins of Valle del Freddo could date back to the end of the last Ice Age - called Würmian, ended about 15-20,000 years ago.
The withdrawal of the glacier has left two evident signs on the territory of Valle del Freddo: the first one is an evident "U" shape characterizing the alpine valleys, the second one is represented by the piled-up material which is formed by small-size pebbles and huge boulders, called erratic boulders. These stones are mainly formed by sandstones and porphyritic conglomerates, typical materials of Valle Camonica. The stratum consisting of pebbles forms the scree.

The Microclimatic Phenomenon

The land morphology plays an essential role in the microclimate phenomenon since it creates the ideal environmental conditions for the growth of high-mountain flora. The microthermal phenomenon derives from the upward air motions between Mt. Grione and Mt. Nà, to which the axial winds of Cavallina Valley superimpose, and from the detritus preserving low temperatures. During the winter, when it rains and snows, water and snow penetrate the underground, where they come into contact with the cold gravel and become ice. During the summer, the detritus maintains the low temperature of the air inside it, making it heavier. The gravity and breezes blowing over the valley lead the icy air to come out of the holes. In summer, the hot and wet air comes into contact with ice, gets cold, and maintains around the exit of these holes the ideal climate to preserve the microthermal flora. Valle del Freddo is characterized by two climates: the general climate, which is not influenced by phenomena linked to the cold air mouths, and the "microclimate" characterizing the microthermal area, where the cold air comes out. The measuring carried out by L. Fenaroli in 1962, between 4.00 p.m. and 5.00 p.m., registered a thermal difference of about 27° between the valley atmosphere and the air coming out of the holes.
Here you are the thermal data, which have also been confirmed by recent studies:

Flora

Flowers from the Cold

On the valley bottom, 32 vegetal alpine species have been found. Since these species are characteristic of the alpine climate, they usually grow in areas completely different from the area of the Reserve.
Around the "holes of the cold" - where the soil reaches very low temperatures - the so-called "microthermal species" can be found, such as Edelweiss, Hutchinsia alpina, Dryas octopelata and Pinguicola alpina. The latter is an insectivorous plant whose fleshy leaves are covered by stalks which can entrap the insects resting on them.
Saxifraga hostii is very common: it forms cushions of yellow flowers with red dots.
Among the shrubs present in the area, Rhododendron hirsutum with its rose flowers, the dwarf pine, and Salix appendiculata are widespread.
As far as one leaves the microthermal area, the vegetation becomes rich in species growing in the hill and mountain plateaus.
In spring, periwinkle plants form a wonderful carpet in the undergrowth. Large carpets of gentians, heath, thyme, and globularia cover the slopes of the area. If you climb higher, Amelanchier ovalis and Hawthorn dominate; in this area the rare and wonderful Peonia officinalis blooms, while the Cyclamen and Centranthus ruber L. are more common plants.
Listera ovata is an orchid which deserves to be mentioned: it can reach the 30-60 cm of height and is characterized by small yellow-green flowers.

Vegetation

The two different climates of the Reserve lead to the formation of four different environments from an ecological and also botanical point of view:

The coppice wood mainly formed by broadleaf trees like the hazelnut tree, the flowering ash, and the hop hornbeam and the Pinewood dominated by Scots pine.

The dry grasslands, where we find species growing on not very deep and dry soils. This area is characterized by the presence of moor grass (giving the name to the moor grass formation), Cytisus emeriflorus and several spontaneous orchids (Listera ovata, Cephalantera longifolia, Platanthera bifolia, Gymnadenia conopsea, Ophrys bertolonii, Ophrys insectifera).

In the scree you can find soapwort, the oxeye daisy, Selaginella helvetica, and the horned rampion.
The flowers growing on the detritus have their roots at a temperature of 4-5° less than the temperature you have a few centimeters on the soil surface.

• List of the characteristic high-mountain flora in the microthermal area (PDF, Italian text - 55Kb)

Fauna

Valle del Freddo Reserve houses the typical fauna of the middle-mountain woodlands and grasslands of Lombardy. Therefore, the fauna is not different from the one characterizing the adjacent areas. Birds represent the most diversified wildlife category (with 28 species): among them the blackbird, the great tit, the chaffinch, the shrike, the greenfinch, the robin, the jay, and the hoopoe. The woods rich in hazelnut trees and pines house several invertebrates and mammals like the dormouse, the hazel mouse, some squirrels, and reptiles like the viper and the western whip snake, the green lizard and the common lizard. Along the trails you can also sight the hare and the weasel.