Torrent Grave San Marco
(photo by: Enrico Vettorazzo)

The territory of the Park is crossed by several watercourses (Cordevole, Mis, and Caorame are the main ones), some of them flowing in narrow valleys and deep ravines. The stream is an extremely dynamic and complex ecological system: the irregular water regime, with a marked contrast between the dry and wet seasons and with periodical floods, implies continuous and sometimes sudden changes in the landscape and in the vegetal and animal communities. The central areas of the pebbly riverbanks often lack of vegetation or are colonized by herbaceous and shrubby vegetation, while, on consolidated alluvial deposits, pioneer vegetation evolves into small riparian woods. The most common situation implies the presence of Speckled Alders, pure or together with shrubby Willows. In more ripen populations, it is possible to find Scots Pines and Spruce Firs or Ash Trees and Mountain Maples.
The Marble Trout, Brown Trout, and Bullhead find their ideal habitat in the streams of the Park. Fishing is regulated in order to favor the reproduction of indigenous species like the Marble Trout and monitoring activities are continuously carried out in order to follow their evolution. Many species of invertebrates and amphibians find food and shelter in riparian habitats.
Certain birds, like the Grey Wagtail and the Dipper, are strictly linked to stream environments.