The Environment
GUIDE OF SAN GIORGIO DELLA RICHINVELDA
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THE ENVIRONMENT
The territory of S. Giorgio della Richinvelda is situated in the middle Friulian plain at a latitude of 46° and at 80/90 metres above sea level slightly sloping from north to south. It spreads out between two important torrential streams: the Tagliamento river to the east and the Meduna river to the west. For this reason it has gravelly soil of alluvial origin, generally called Grave with natural habitat typical of the area (fig. 55). The territory of the Meduna river, together with the Cellina river, a tributary of the Meduna, create a large area with shrubbery, called Magredi.
Between the inhabited area of S. Giorgio and the Meduna river, once the prairie of the Richinvelda spread out, which gives the name to the town. The area has been reclaimed, and in the latest decades, thanks to irrigation, quality vineyards and fruit fields have been planted. Between the pebbly riverbanks there is a strip of more fertile soil which spreads out from the inhabited area of Provesano towards south/south-east as far as S. Martino al Tagliamento
In the course of the time the Tagliamento river has not undergone anthrophic modifications, with the exception of the embankment of the 19th century, carried out to protect the inhabited areas and the cultivations. Water flows on the surface irregularly, depending on the rainfall in the mountains, while under the gravel it is generally present, and it resurfaces downstream. In the Meduna, instead, water is generally absent, as dams have been built in the mountains. Only when the reservoirs are refilled, surplus water is drained off for some days of the year.
The climate is temperate with frequent rain (1500mm average in 120 days with rain) also in summer, owing to frequent rainstorms; the rainiest seasons are autumn and spring. The mean temperature is 13°C and it varies from a mean temperature of 3°C in January to 23°C in July. Temperatures can occasionally fall below -10°C in winter and exceed 35°C in summer. These limits are rarely exceeded, even if global warming in the latest decades has fostered warmer summers with maximum absolute peaks of 38°C. In spite of heavy rainfall the type of soil needs irrigation of cultivations which consist mainly of maize, soyabean, fruit, and vines. As far as vines are concerned, there are both vineyards for the production of grapes and fields for the cultivation of vines used as rootstock, needed to produce grafted cuttings, “the barbatelle”.
The territory is not rich in easily accessible water resources, like the areas situated a few kilometres to the south where water resurfaces. For this reason from the Cosa stream in the 13th century the “Roggia di Lestans” or “Roggia dei Mulini”( Stream of the Mills) was diverted, which supplied drinking water and mechanical energy until the first its function is no longer relevant, but it is protected as environmental heritage. Its historical importance is undeniable for different reasons: social, economical, and why not, cultural decades of the 20th century, and was considered one of the oldest and most important in Friuli. Nowadays.
The “Magredi”
The hamlets of Domanins and Rauscedo are bounded to the west by the Meduna river and include a small portion of the “magredi”, an area characterized by many metres deep of pebbly and gravelly soil.
In the past they were open grassland used as pastures or for haymaking and today, considerably reduced as a result of the agrarian transformations of last century, they represent a naturalistic heritage and precious evidence of the ancient steppe environment following the glacial period. The landscape consists of wide dry areas, even if the vegetation of the “magredi” is varied, and from the naturalistic point of view, is one of the most important habitats of Friuli Venezia Giulia (fig. 56).
The flora is among the richest and most varied in the region and includes some endemic and rare species. Noteworthy are the “Brassica glabrescens”, a species typical of the magredi of Pordenone, the “Matthiula fruticolosa ssp”, the “Valesiaca”, the “Centaurea dichroantha”, the “Euphorbia trifora ssp. Kerneri ssp”., the “Stipa pennata” - feather grass - (fig. 57) and others. A rare plant of steppe origin is the “Crambe tataria” (fig. 58), common in the steppes of Eastern Europe and Central Asia and present only in some areas of the “magredi”.
Also fauna includes some species typical of the steppes or of open habitats, such as the hare, some species of lizards, snakes, amphibians and several species of insects. Some predators are present like the buzzard (Buteo buteo), the harrier and the hen harrier (Circus pygarsus e cyaneus), the kestrel (Falco tinnunculus), the peregrine falcon (Falco peregrinus), and others. Among the fowls there is the partridge, the stone curlew, the little ringed plover, the lapwing, the cuckoo, the goatsucker, the hoopoe, and other smaller birds. In the woody areas deer, roe-deer and wild boars coming from the Pedemontana find shelter.
Since 1978 this territory has been preserved and protected by regional planning legislation.
The Tagliamento River
The Tagliamento river bounds the eastern part of the Municipality, including the hamlets of Provesano, Cosa, Pozzo and Aurava, with an expanse of polychromatic gravel which reflects the geology of the mountains (fig. 59).
The earliest documentary evidence of the hydronym was given by Pliny the Elder (23 – 79 A.D.) who in the Naturalis historia (III, 126) mentions the “Tiliaventum Maius Minusque” consisting of two branches. The name comes either from the Indo-European root telia/tilia which means “lime tree”, whence “place of the limes”, or from the Celtic telo, “spring”.
It is considered the only river in the Alps, and one of the few in Europe, which maintains a morphology of interlaced branches. It is studied by universities and research centres all over the world as a model for interventions of river re-naturalisation. It is considered an extremely rare and interesting ecosystem, the last river in the Alps which has not been morphologically modified and where man’s intervention has been limited.
Typical of this river is the phenomenon called “dealpinismo”: plants which grow in the mountains screes appear in the river-bed transported by water.
The river-bed, apparently a bare gravel expanse, is mainly characterized by herbage resistant to floods; on the higher gravel banks, with occasional flooding, shrubbery appears, but also black poplars and white willows. The same habitat can be found in the islets (also called “saletti”, in Friulian “salets”) which form among the branches. Finally in the holms, where flooding is less frequent, permanent vegetation grows, consisting of white poplars and alders and numerous animal species like deer, wild boars, badgers, foxes and hares find shelter. The river-bed of the Tagliamento is also the “ corridor” for many migrant birds which often use it to nest.
The river flooded many times in the course of the centuries. The first flood recorded by historians occurred in 1275. Fifty-nine floods have been recorded since then, the most destructive one in the 20th century was on November 4, 1966 when the villages near the bank were flooded.
