The considered territory is inserted in the northern zone of the province of Treviso and includes a large lowland area, to which is added part of the pre alpine ridge that stretches from Mount Cesen to Cansiglio, passing through the Col Visentin. The central nucleus is represented by the sub-pre alpine hills that compose the Core Zone, the heart of the Site that, thanks to the landscape and rural peculiarities, has made it possible to obtain recognition as a World Heritage Site. It is a series of parallel reliefs called “hogback”, which extend between the small towns of Valdobbiadene and Vittorio Veneto, interrupted by transverse incisions of variable amplitude.
The hills are formed by resistant layers of conglomerate, sandstone or limestone, while the depressed bands follow the layers of clay or marl.
This type of landscape, called by geologists “monoclinale”, in the configuration in which we find it in the “Alta Marca Trevigiana” is unique worldwide.
There are other examples in Iran and the USA, but they are free from the scenic component given by the vegetation of our Hills.
The rocks are “sisters” of those we find in Valbelluna and, in fact, were in continuity with these at the time of their formation on the bottom of the sea, between 30 and 4 million years ago. Later, the tectonic movements caused by the African continent’s push against the European during the last 4 million years, have arched the entire geological structure forming the Prealps. Selective erosion has finally removed most of these materials, producing the debris that form the Venetian plain, and creating the relief with parallel ridges that represents the southern flank of an anticlinal fold. The lavers rose from their horizontal position of origin, remaining inclined by about 70 degrees. The more resistant ones draw the long line of parallel Hills so beautiful and so characteristic, the spectacle of nature that we all know.
The vegetation of the territory considered here, is very heterogeneous, developing from the plain to the greater heights of the pre-alpine ridge. It has been profoundly modified by human activities through agricultural crops: maize, vineyards and stable meadows, which are now less and less frequent and are also replaced by vineyards. Primeval forest has also been affected by the uses and, for example, the locust has often replaced oaks, hornbeam and other deciduous trees. The same chestnut was largely favoured (important and famous formations above Combai and Miane) and helped to modify the characteristics of the soil.
The potential series includes the oak-hornbeam (with guide species farnia and white hornbeam, lowland and hilly), the orno-ostrietus (orniello and black hornbeam) in which the oaks (rovere and roverella) have often been supplanted by hornbeam. Maples, asher and tiles characterise the cooler slopes with less arid soils. Starting from 600-800 m, gradually, the prevailing species becomes the beech, while the presence of conifers is only sporadic and often artificially favoured. At the largest altitudes represented by Monte Cesen (m 1570) and Col Visentin (m 1763) there are grasslands arranged on the southern slopes above the current limit of the forest, often arid-rocky, alternating with areas once subject to mowing or grazing and today abandoned. An important role for biodiversity is supported by communities, arboreal or often shrubs, which forms hems and cloaks that characterize the clearings, border and lightening following the cuts.
As for fauna, there is a fair presence of wild mammals. The wide clearings alternating with woods of the pre-alpine area constitute the ideal habitat for roe deer, which is not uncommon to meet even in the hilly strip of the valley floor. The noble deer, which in recent decades has seen an authentic numerical explosion, meets in the hilly areas on the edge of the plains in search of new spaces in which to stabilize. In recent years, reports of wolves have multiplied, present on the reliefs with some stable herd and some erratic individual even in the plains, while the exponential growth of wild boars has become a serious problem for farmers as these animals cause substantial damage to high-altitude meadows and crops in the areas of plains and hills. Good the presence of the fox, the badger, the stone marten, the pine marten, the latter on the reliefs, while, among the rodents, there is a widespread presence of the squirrel and the dormouse. Finally, it is worth remembering the common hare, which can be found in particular where there is a good alternation of meadows and wooded areas.
Speaking of birdlife, in relation to the valley floor strip connected to the lake basins, we point out the mallard, the teal, the coot, the moorhen, the white heron and the ash heron, the grebe in the Valley Lakes, and numerous other species related to aquatic environments. In the cultivated belt live the greenfinch, the starling, the pheasant, the lark, the shrike, the goldfinch, the plaice, the magpie. In the wooded areas we find the siskin, the common groin, the wood pigeon, the finch, the thrush, the nightingale, the oriole, the green and red woodpecker, the blackbird, the cuckoo and the turtledove.
There are numerous birds of prey, present in the open areas alternating with hedges and wooded areas: the buzzard, the kestrel, the hobbyist, the goshawk, the sparrowhawk and, over 1000 m of altitude, some specimens of golden eagle and short toed, beyond tetraonids such as the fork rooster and the capercaillie. Among the nocturnal birds of prey, there are the civetta, the allocco and the gufo.
Good the presence of reptiles such as the common viper at altitude, the biarat snake, the smooth stalk, the Aesculapian snake, the slow worm, the lizard, the green lizard and, speaking of amphibians, to remember the common toad, the temporary frog, the spotted salamander, the alpine and dotted tritone and, among the rarest and most protected presences, the Lataste frog, endemism of the Po Valley, the howl with a yellow belly and the crested newt.
The GDP (parks of local interest) also deserve a quote, in particular the Parco del Rujo in the municipality of Cison di Valmarino, the “Parco dei Laghi della Vallata di Revine e Tarzo” and the Parco Grotte del Caglieron in the municipality of Fregona. To these are added the areas of great naturalistic value protected by Natura 2000, which invest the territory in question. Despite their specificities, we limit ourselves to listing them: Gruppo del Visentin-M. Faverghera-M. Cor; Passo di San Boldo; Monte Cesen; Perdonanze e corso del Monticano; Laghi di Revine; Palù del Quartier del Piave; Grave del Piave; Dorsale prealpina tra Valdobbiadene e Serravalle; Ambito fluviale del Livenza e corso inferiore del Monticano; Grave del Piave-Fiume Soligo-Fosso di Negrisia; Fiume Meschio e Settolo Basso.