Description
The biotope is set in a pleasant and picturesque landscape, whose soft lines are the result of the shaping action of the glaciers of the Quaternary period, which ended about 15,000 years ago. The glacier, which used to occupy the entire valley, smoothed out the slopes and hollowed out the bottom, thus creating the depression that hosts Lake Serraia.
The biotope presents a remarkable environmental variety, due to the different degree of soil humidity in the different portions of the area.
Perhaps the most important sector of the protected area is the lakeshore with the portion of water in front of it.
The shore is bordered by a strip of reed thicket, dense vegetation composed of water reed (Phragmites australis), a grass that grows where the water is only a few decimetres deep, but also on dry land, provided the soil is soggy.
The cane thicket is the nesting environment for several species of water birds, whose presence lends considerable faunal interest to the biotope, an interest further enhanced by the high altitude of the protected area, almost 1000 metres, which is unusual for this fauna. The most easily observed species are the mallard (Anas platyrhynchos), the coot (Fulica atra) and the rare great crested grebe (Podiceps cristatus). In spring and autumn, this quiet area of the lake offers resting and refuge for passing species during migration.
The remaining part of the protected area consists of a mosaic of marshy meadows more or less invaded by water reed, alternating with small areas with willow bushes (Salix, various species), thickets and rows of black alder (Alnus glutinosa) and white alder (Alnus incana).
This environmental mosaic represents an extremely favourable situation for fauna, as it offers multiple feeding and breeding possibilities for many animals.
Until not so many decades ago, the wet meadows were partly occupied by crops, mainly cabbage and potatoes, which were abandoned due to low productivity; to this day, a series of regular lines can still be recognised on the ground, testifying to the presence of the old plots. Nature quickly regained its territories and plants typical of marshy areas have reoccupied the basin; among these, the most common are sedges (Carex, various species), which often grow in large tufts.
The watercourses running through the biotope are also very interesting, including one of the main tributaries of the lake. They are a receptacle for various types of aquatic plants, such as the showy mazzasorda (Typha latifolia), and are home to a rich invertebrate fauna, including the crayfish (Austropotamobius pallipes). In spring, these watercourses, in the low current sections, are frequented by the toad (Bufo bufo) and the mountain frog (Rana temporaria), which come here from the nearby forests to mate and lay their eggs.