The environment: man and nature
The ecosystems
Rocks, screes, and niveal valleys
The vegetation on a mountain chain like the Orobie mountains is influenced mainly by the altitude which determines considerable variations in climate.
If we imagine flying like an eagle from the top of Pizzo Coca, the highest peak, down the slopes to the valley floor, we will see different environments each with its own particular kind of vegetation.
Our departure point is made of compact rock with practically no vegetation. Few plants survive at this altitude although lichens can be found well above 3,000 metres (9,000 ft). On siliceous rock - and most of the rock in the part is of this type - grows a yellow lichen, Rhyzocarpon geographicum, while in cracks that have gathered a little soil some small cushion-forming plants survive (Androsace vandelli, Androsace brevis).
Just below the crests of the mountains are screes and moraines. They are both formed by debris from the crumbling of the rocks. In the screes the crumbled rock accumulates through gravity while in the moraines it was moved by the action of glaciers. Some alpine plants (Androsace alpina, Linaria alpina, Corydalis lutea and Crytogramma crispa) adapt to these instable surroundings and it is here, in the central-eastern valleys of the Park that the endemic species, Viola comollia, can be found.
In the hollows where the snow gathers the vegetation cycle lasts only for the summer months. These so-called niveal valleys are similar to the Arctic tundra, where there are various mosses and carpets of salix herbacea, a willow that adapts to severe climates. Flowers like the Soldanella pusilla or the Arenaria biflora can also be found.
Only animals and birds which have developed special survival strategies can survive these harsh conditions. The ptarmigan (Lagopus mutus) is the best example; it can change the colour of its feathers so that in winter it is snow-white. It survives by pecking at the small branches that emerge from under the blanket of snow.
The ibex (Capra ibex) survives harsh winters thanks to the fat it accumulates in summer, and by choosing steep sunny slopes where snow cannot gather.
Birds that stay at high altitudes in winter include the snow finch (Montifringilla nivalis) the alpine accentor (Prunella collaris) and the wallcreeper (Tichodroma muraria), as well as their predator, the kestrel (Falco tinnunculus), which nests in fissures in the rocks.
The alpine chough, a kind of crow, (Pyrrhocorax graculus) and the raven (Corvus corax) also nest here, while the golden eagle (Aquila chrysaetos) hunts here but nests lower down.
Water-lands and peat bogs
Streams, lakes and peat bogs have different characteristics according to the altitude and other environmental factors. Springs and streams at a high altitude are not suitable for plants like Saxifraga stellaris, Cardamine asarifolia and Pinguicola vulgaris which grow in lower areas. The yellow Saxigraga aizoides dominates pebbly stream beds. In some shallow lakes or ponds aquatic plants like Spargarium angustifolium grow; this plant covers the surface of Lago Culino in Val Gerola for example. Peat bogs form around these lakes or ponds when water stagnates; decomposition is slowed down by lack of oxygen and the acid environment and so peat is produced. Plumes of cotton grass, like balls of cotton wool, stand out in the midst of moss, sphagnum, sedge and reeds.
Aquatic environments are found at different altitudes and their waters have different characteristics which determine animal life. High altitude lakes have short food chains, with small invertebrates such as the water flea (Daphnia s.p.) at the top. In still waters below 2,000 m. (6,000 ft), including ponds for cattle to drink from, there are insects like the dytiscus and some vertebrates such as the newt (Triturus cristatus) and the red mountain frog (Rana temporaria). In the breeding season they attract a formidable predator, the grass snake (Natrix natrix).
Dragonflies are common near the peat bogs but sometimes Parnassius butterflies can be seen too.
In streams that have a lot of oxygen there are Pleocoptera larvae, a favourite dish for the dipper (Cinclus cinclus), a little bird that swims under water to find food among the pebbles.
Running water also attracts the grey wagtail (Motacilla cinerea).
Alpine meadowlands
Just below the rocky environments, where soil can gather, we find the alpine meadows, covered in grass. Between 2,500 and 2,700 metres (around 7,000 - 8,000 feet) in the Alps there are grasslands characterised by Carex curvula grass, with thin leaves that curve in summer due to a parasite fungus.
There are not however many meadows of this kind in the Orobie mountains in Valtellina, because the slopes are too rocky, and the sunny slopes are characterised instead by tufts of Festuca scabriculmis grass.
The alpine anemone (Pulsatilla alpina) and Koch’s gentian (Genziana kockiano) add yellow and purple to this environment, and we also find two rare species: Allium victorialis and anemone narcissiflora.
In the pastures tussocks of Nardus strica are often interspersed with flowers such as alpine clover (Trifolium alpinum) as well as Arnica montana and the spotted Gentiana punctata.
The meadowlands come to life in summer. Flowers and animals suddenly appear as soon as the snow melts. Marmots come of out the dens where they hibernated, the chamois (Ripicapra rupicapra) returns from the woodlands where it found food in winter, and the northern wheatear (Oenanthe oenanthe), a small migratory bird, returns from its winter stay in Africa.
The black redstart (Phoenicurus ochruros) and the water pipit (Anthus spinoletta) come back to feed on insects, which are abundant in summertime.
If you are lucky you might see an ermine (Mustela erminea) chasing its favourite prey: the snow vole (Chionomys nivalis). But it is more difficult to spot the mountain hare (Lepus timidus) which hides during the day to escape the attention of the golden eagle which often flies low over the meadows. And it is more and more difficult to spot the rock partridge (Alectoris graeca) on the sunny slopes.
Cold-blooded animals find life even harder at high altitudes. The black salamander (Salamandra atra) and the viviparous lizard (Zootoca vivipara) instead of laying eggs keep them inside their bodies so that they can hatch in the warm. In this way when their offspring are born they are already able to move and find food.
Shrub-lands
As we descend the slopes, before we come to the conifer woodlands, we come across an area of shrubs, varying according to soil and exposure.
The rhododendron or alpine rose (Rhododendron ferrugineum) is found on the damp, shady slopes, while the juniper (Junipers sp) grows on the dry, sunny slopes. The green alder tree (Alnus viridis) is also found here, as well as an endemic species, the Sanguisorba dodecandra. The alders stretch down towards the woodlands, while the mugo pine (Pinus mugo) is less common.
The bird that is the symbol of transition from alpine meadow to woodland is undoubtedly the black grouse (Tetrao tetrix). The male is blue-black with white feathers under his tail and red markings above his eyes, while the female’s plumage offers her camouflage while she sits on her eggs. The adder (Vipera berus) is another inhabitant of this environment, but it tends to keep out of sight while watching for its prey.
Some birds that can be spotted include the shy dunnock (Prunella modularis) or the linnet (Carduelis cannabina) and the redpoll (Carduelis flammea), both red-breasted. The tree pipit (Anthus trivialis) which lets itself drop from a treetop with its wings open like a parachute is something special!
This environment is full of colour in the summer thanks to the flowering rhododendrons and the multicoloured butterflies.
Conifer woods
The spruce fir (Picea abies) is the most widespread conifer in the Orobie mountains, and the woods are known as sub-alpine fir-woodlands or mountain fir-woodlands according to altitude.
The sub-alpine fir-woods stretch from 1,500 m to the tree-line, and at the highest altitudes the spruce fir is found along with the European larch (Larix deciduas) and sometimes with the Swiss stone pine (Pinus cembra).
The mountain fir-woods stretch from the end of the hardwood forest of broad-leaved trees to around 1,500 m. On the shady, damp slopes in the most western valleys of the park the silver fir is found (Abies alba), while on the sunnier slopes the Scots pine (Pinus sylvestris) is often the dominant tree.
The higher reaches of the conifer woods are the favourite habitat for the pygmy owl (Glaucidium passerinum), a tiny nocturnal predator which nests in holes made by the great spotted woodpecker. Lower down, in the spruce fir woods, Tengmalm’s owl nests in holes abandoned by the black woodpecker (Dyrocopus martius), the largest of the European woodpeckers. Woodpeckers, owls and squirrels too must watch out for attacks from the pine marten (Martes martes).
Small birds use different parts of the conifers in their search for food. The crossbill (Loxia curvirostra) feeds on he treetop, using its well-adapted beak to extract fine-nuts from the cones; the treecreeper (Certhia familiaris) finds larvae on the trunks; the goldcrest finds insects and spiders in the leaves. The coaltit (Parus ater) prefers to feed on the ends of branches while the crested tit (Parus cristatus) hides in the foliage.
The fir woods of the Orobie mountains are a suitable environment for the capercaillie (Tetrao urogallus), a large grouse which has become the symbol of the park. It is an endangered species and is becoming rarer. The hazel grouse (Bonasa bonasia), smaller but equally hard to see, shares part of the same habitat. They both need carpets of blueberries to feed on in the mating season.
Broad-leaved woods
Woods of broad-leaved trees cover the Orobie slopes from 1000m (3000 ft) (the lower limits of the park) to the valley floor. The chestnut (Castanea sativa) is the predominant tree; in the past it was exploited for its fruits, its wood and even for its leaves which were used in cowsheds in place of straw. In the western valleys of the park, beech woods are found, and with the beech are found the sycamore maple (Acer pseudoplatanus), the European mountain ash or rowan (Sorbus aucuparia) and the silver fir. Flowers like the liverleaf (Hepatica nobilis) bloom in spring before the leaves of the trees block out light coming to the forest floor.
The lower levels of broad-leaved wood, where the chestnut is not predominant, are characterised by the birch (Betula pendula), the European ash (Faxinus excelsior) and the small-leaved lime (Tilia cordata).
In the Valtellina Orobie mountains, these woods are often interrupted by hayfields, created in the past by deforestation. This area between two environments is rich from a biological point of view, for we find species from both of them as well as others which explicitly need this transition area. Two birds of prey are an example of this: the buzzard (Buteo buteo) which nests in the trees and the eagle owl (Bubo bubo) which nests on the rock walls protected by the woodlands. Both hunt in the bordering open spaces. Other animals which take advantage of the environmental diversity are the hare (Lepus europaeus) , the roe deer (Capreolus capreolus) the badger (Meles meles) the beech marten (Martes foina) and the fox (Vulpes vulpes).
The tawny owl (Strix aluco) hunts and nests in the woods while the rarer little owl (Athene noctua), prefers open spaces. The jay (Garrulus glandarius) and the green woodpecker (Picus viridis) can be recognised by their cries.
In autumn, on wet days, a strange black and yellow little creature can be seen on the carpet of leaves on the forest floor: it is the fire salamander (Salamandra salamandra), which uses its colours to warn off possible predators.
