ENVIRONMENTS

Plain forest
The reclamation works mostly  carried out between 1927 and 1938 in the Southern plain of Monfalcone saved only a few strips of the large marshy plain forests that originally flourished in the whole area. Despite man’s intervention and their fairly small dimensions the so called “Bosco Grande” (Big wood) and the Alberoni wood represent the remains of such environments that present peculiarities as far as vegetables and fauna are concerned. Some rare bird species usually nest in the area: diurnal and nocturnal birds of prey, the wood pigeons, the Eurasian Nuthatch, the Eurasian Wryneck and more recently the Black Woodpecker.



Woods and floodplain woods
Woods and undergrowth flourish in the floodplains of the Reserve, particularly in the northernmost part and in the Southern strip of the bridge on the provincial road Monfalcone Grado. The main arboreous species are the White Willow, various types of the Populus, the Fraxinus Oxifillus, the Black Alder and the Robinia. Marginal strips are covered with brambles, as well as the river banks that are often covered with Robinia. Large areas are colonised by the Amorfa Fruticosa, a weed shrub that originally grows in Northern America.
These environments are of vital importance for some species of birds both during nesting and during migration when they host a high number of passeriform birds.



Salt marshes
Salt marshes are areas that rise out of the sea water in the Reserve. They are generally covered with low vegetation and they are exceptionally submerged by sea water only during high tides. The soil of salt marshes is characterised by a high percentage of salt and this factor is the reason for the thriving of the typical halophilic vegetation (they live in environments with very high concentrations of salt) such as the Sea Rush or Juncus maritimus, the Limonium etc..
Transition areas between floodplains and mud flats are usually filled with cordgrass strips (Spartina).
Sea water seeps into the floodplains through tortuous channels and gullies During high tides Isola della Cona hosts some birds’ dormitories in the most quiet sandy areas. Some of these birds are the Eurasian Curlew (the symbol of the Reserve) and the Grey Heron. 

Mud flats
Velme are muddy or sandy sea floors that cyclically emerge from the water thanks to low tides.
They account for about one third of the entire surface of the Reserve.
Velme are partially populated by meadows of Zostera noltii and seaweeds but sometimes there is no vegetation on their surface (on muds, on fine sands and near the mouth bar). Many different species live in such environments and they represent the favourite food of limicolous birds such as the Eurasian Curlew and the Dunlin. In Winter, after hunting was officially prohibited in the Reserve, large flocks of aquatic birds flood mud flats where the Wigeon and the Eurasian Cood are among the most numerous species.  



Sandy deposits and gravelly isles at the river’s mouth
Punta Spigolo, the left side area of the Isonzo river’s mouth, is characterised by an extraordinarily dynamic environment. It is shaped by the sea, by the wind (Bora) and by the river that deposits large amounts of sand and gravel when frequently flooding. External sandy isles, sometimes covered with thin vegetation, are key to the nesting of some vulnerable and threatened species such as the Little Tern and the Eurasian Oystercatcher. Besides, when there is high tide they represent a good perch for other birds like Cormorants, limicolous birds and Seagulls.   

 The Exposed gravelly river bed and the river environment  
In the Northern area of the Reserve, from the confluence with the Torre river to the bridge of the provincial road Monfalcone Grado, the Isonzo’s course is characterised by large gravel and sandy layers that are visible when there is the minimum flow.
In the highest parts of these isles there are often thick willow woods that resist the strength of the river’s impact during floods. Open gravelly environments particularly suit birds when nesting (the Little Ringed Plover and the Common Sandpiper).

 Farming
Some areas of the Reserve are dedicated to farming, mainly corn, soy and beetroots besides considerable artificial implantations of populus hybridus for cellulose. Usually, farming lands are poor in spontaneous vegetation and animal species, made exception for some banks covered with bushes and some  artificial channels with resurgence water where the typical aquatic vegetation firmly resists.  Birds such as the Crested Lark and the African Stonechat nest on the strips of the farming land  while the European Golden Oriole prefers Populus woods. In Winter farming lands are populated by  the Ardea and the African Linsang (Poiana).



Grazing and meadows
Some areas of the Reserve are dedicated to grazing lands where big herbivores like horses and bovines play an important role.
In the 80s, after grazing had been temporarily set aside, the area was gradually populated by reed beds and bushes. At the moment this trend is encouraged by denying cattle access to some areas. In other cases, the reintroduction of cattle allowed to reclaim meadows besides considerably increasing the biodiversity of many vegetable and animal species.



Temporary and perennial fresh water marshes and environmental restorations.
Such environments had almost completely disappeared in the Reserve because of extensive reclamation works. Only in the 90s they were gradually restored. In Isola della Cona those areas which had been reclaimed and embanked were reshaped later. These changes occurred by excavating and by planting the existing sluice gates in the ground. In a second phase they were flooded with rainwater and artesian aquifer water.
This is how freshwater marshes originated and how they became characterised by different depths. In addition, such marshes are managed in order to make them a sort of rescue and a food source for all numerous species of birds in all seasons. In the restored areas surrounding the visitors’ centre there are many couples of nesting limicolous birds such as the Northern Lapwing, the Black-Winged Stilt and the Little Ringed Plover. During Autumn and Winter these areas host many ducks and geese as they like to enjoy the quiet atmosphere and the deep waters.
During  Spring and Autumn migrations, limicolous birds go hunting invertebrates in the wet meadows and in low waters. In Summer, Ardeas feed on frogs and fish in low waters that underwent a process of evaporation while many ducks complete their moult. Reed beds (the Phragmites australis or the common reed, the Bulrush or Schoenoplectus lacustris and the Typha) and wet meadows with different species of herbs are the main vegetation. After vegetation is partially mown in Summer, open large areas become very attractive for aquatic birds. Besides, the periodic drying up and the sudden flood of some marshy areas are key elements to increase the number of species in the Reserve.



Reed Beds
Punta Sdobba’s large reed ticket, called “Caneo”, is affected both by the Isonzo’s fresh waters and by the sea salty waters. The reed beds are higher and denser in those areas which are close to the river while their height and density tend to decrease where there are gullies and channels communicating with the sea. Here is where the Common Reed is replaced by the Bulrush (Schoenoplectus lacustris).
Meadows of the Sea Rush (Juncus Maritimus)  and of the Saltmarsh Rush (Juncus Gerardii) are very widespread as well. Less large but highly interesting Reed beds grow along the final strip of the river’s left bank, in the area of environmental restoration and in just a few fresh water marshy areas.
This is where the process of reproduction occurs for different species of birds, such as the Little Bittern, the Purple Heron, the Reed Warbler and the Great Reed Warbler.

Underwater seaside areas
In the Reserve the seaside areas are not very deep (maximum 3 – 4 metres of depth) and the seafloors are mainly composed of muddy sands and superficial fine sands. This is where wide meadows of sea phanerogams (herbs) develop. Such habitats rescue a great number of species of fish, crustaceans, molluscs and other invertebrates during all the phases of their evolution. In addition, in Winter they are populated by many different birds and particularly by the Western Grebe, the Great Cormorant, the Seaduck and the Eurasian Coot while in Summer it is possible to observe the European Shag. The Mute Swan is always present throughout the year.