Description
The Roncegno Marshes represent, together with the Fontanazzo Biotope, one of the last and most important riparian woods on the valley floor in the Province of Trento.
The continuous and abundant water supply guaranteed by the Rio Chiavona and other minor streams keeps the land in a state of perennial water stagnation, also thanks to the fact that these streams are not channelled and therefore branch off into numerous surface rivulets that disperse over a wide area.
Despite numerous human interventions, this area still retains the characteristics of the ancient wooded landscapes of the valley floor, both in terms of the structure of the vegetation and the floristic species present.
The presence of water in the soil, consisting mainly of alluvial silts, sands and gravels, is the indispensable condition for the development of marsh vegetation.
The wooded portion is predominantly composed of an alder grove of black alder (Alnus glutinosa) and white alder (Alnus incana); there are also numerous groups of willows, including the ash willow (Salix cinerea) and the imposing white willow (Salix alba).
In general, the forest has a relatively young structure, testifying to the cuts carried out until recent times. In various stretches the alder wood is interrupted by clearings occupied by wet meadows or invaded by marsh reeds; these open environments are very important because they contribute to increasing the degree of diversity of the marsh ecosystem.
Many animals find refuge and breeding possibilities in the Roncegno marsh. The tangle of vegetation provides safe shelter for many mammals, even large ones, such as the roe deer (Capreolus capreolus), the badger (Meles meles) and the fox (Vulpes vulpes).
The most varied component of the fauna, however, is made up of birds: numerous silvicultural species frequent the foliage and undergrowth, but the most valuable entities are those most closely linked to water, such as the mallard (Anas platyrhynchos), the water rail (Rallus aquaticus) and the green warbler (Acrocephalus palustris).
The receptive capacity of the biotope for aquatic fauna has been significantly increased following the creation of a pond system in the place of a former landfill site and in a previously 'dry' and uninteresting area. The ponds attract water birds, including herons (Ardea cinerea) and mallards; dozens of mountain frogs (Rana temporaria) and common toads (Bufo bufo) lay their eggs in their still waters in spring.
